Whittle Dene Catchment Project

Phase I Study Report 2002 - 2005

Final Report

Whittle Dene Catchment Project

Phase I Study Report 2002 – 2005

Final Report

Report prepared by ADAS UK for Defra under contracts PSO 0430 and PL 0553 J Hillman, M. Shepherd, C. Proctor, S. Cartmell, S Hadden, C. Murray & J. Fowbert ADAS UK, Meden Vale Mansfield Nottingham NG20 9PF UK and J Jonczyk School of Civil Engineering and Geosciences Cassie Building University of Newcastle upon Tyne NE1 7RU UK Email: jonathan.hillman@adas.co.ukTel: +44 (0)1623 844331

CONTENTS

ACKNOWLEDGEMENTS.............................................................................................i EXECUTIVE SUMMARY..............................................................................................i LIST OF DEFINITIONS, ACRONYMS AND ABBREVIATIONS ..................................x

1. INTRODUCTION ............................................................................................... 1 1.1 Water quality and the WFD .........................................................................................1 1.2 Whittle Dene project description .................................................................................3 1.3 The importance of land management for water quality ...............................................1

2. METHODS......................................................................................................... 7 2.1 Project management ...................................................................................................7 2.2 Establishing catchment studies – practical considerations .........................................7 2.3 Whittle Dene Western Catchment Characterisation....................................................8 2.4 Water quantity .............................................................................................................9 2.5 Water monitoring strategy ...........................................................................................9 2.6 Water quality .............................................................................................................11

2.6.1 Nitrate and phosphorus analysis ..................................................................................... 11 2.6.2 Sediment analysis............................................................................................................ 12 2.6.3 Pesticide analyses ........................................................................................................... 12 2.6.4 Faecal indicators and pathogens..................................................................................... 12

2.7 Pesticides selection for the monitoring project ..........................................................13 2.8 Application of models for catchment characterisation...............................................13

2.8.1 Pesticides......................................................................................................................... 14 2.8.2 Nitrate modelling.............................................................................................................. 14 2.8.3 Sediment.......................................................................................................................... 14

2.9 Soil assessment ........................................................................................................14 2.10 Historical Water Quality Data.................................................................................15 2.11 Farm & field survey ................................................................................................16 2.12 Aquatic survey .......................................................................................................16

2.12.1 Identification and enumeration of samples ...................................................................... 18 2.13 Vegetation assessment..........................................................................................18 2.14 Mobilisation and delivery of N and P......................................................................18

3. RESULTS ........................................................................................................ 20 3.1 Physical description ..................................................................................................20 3.2 Concentrations of nitrate in recent years...................................................................23 3.3 Concentrations of pesticides in recent years.............................................................25 3.4 Rainfall and flow 2003 - 2004....................................................................................26 3.5 Water Quality in the Whittle Dene Western catchment 2002 – 2004 ........................28

3.5.1 Pesticides......................................................................................................................... 29 3.5.2 Microbial indicators and pathogens ................................................................................. 31 3.5.4 Phosphorus and sediment ............................................................................................... 34

3.6 Soil Mineral Nitrogen and Phosphorus in fields in the WDWC..................................37 3.7 Soils and drainage ....................................................................................................40 3.8 Surface and subsurface flow.....................................................................................43 3.9 Vegetation survey .....................................................................................................46 3.10 Aquatic survey .......................................................................................................46

4. DISCUSSION .................................................................................................. 50 4.1 Objectives .................................................................................................................50 4.2 Pesticides..................................................................................................................50 4.3 Microbial Indicators ...................................................................................................56 4.4 Nitrate........................................................................................................................60 4.5 Phosphorus and sediment ........................................................................................63 4.6 Soils and drainage ....................................................................................................66

5. CATCHMENT PLAN........................................................................................ 72

5.1 Catchment planning for agriculture and water quality ...............................................72 5.2 CAP reform ...............................................................................................................73 5.3 ELS and HLS ............................................................................................................74 5.4 Farming in the North East .........................................................................................75 5.5 Characteristics of holdings in the WDWC .................................................................77 5.6 Multiple options presented as a catchment plan 2005 - 2007...................................78

5.6.1 WDWC and cross compliance......................................................................................... 78 5.6.2 WDWC, ELS and HLS ..................................................................................................... 79 5.6.3 WDWC and voluntary additional options ......................................................................... 81

5.7 Research plan ...........................................................................................................83 REFERENCES ......................................................................................................... 85

APPENDIX 1. ........................................................................................................... 91

APPENDIX 2 ............................................................................................................ 95

APPENDIX 3 ............................................................................................................ 97 Table of Tables Table 2.1 Description of the main sampling points in the Whittle Dene catchment.. 11 Table 2.2 Selected pesticide characteristics............................................................ 13 Table 3.1 Monthly rainfall 2003-04 and long term average rainfall 1941-70 ............ 27 Table 3.2 Loads of phosphorus, nitrate and IPU at gauging stations in the............. 36 ................................................................................. 36WDWC 2003 - 2004Table 3.3 SMN Index (0-90 cm) of fields in the WDWC 2002-2004......................... 39 Table 3.4 Olsens P index (0-15 cm) of fields in the WDWC February 2003 ............ 40 Table 3.5 Drainage pipe type and permeable fill type numbers and percentages

installed in Northumberland and Parishes around Whittle Dene.............. 44 Table 3.6 Habitat types at sampling locations along Whittle Burn ........................... 47 Table 3.7 Proportion of organisms collected with similar BMWP scores for each site

........................................................................................................................... 47Table 4.1 Routes of environmental contamination by pesticides ............................. 55 Table 5.1 Transition to Flat Rate Payments 2005-2012 .......................................... 73 Table of Figures Figure 2.1 Map of the WDWC and surrounding area (inside red line) .................... 9 Figure 2.2 Aerial image of the WDWC (inside red line) ........................................ 10 Figure 2.3 Environment Agency Sampling Points in the Whittle Dene Area......... 15 Figure 3.1 Schematic diagram of the reservoir network (Source: NWL)............... 21 Figure 3.2 Concentrations of nitrate-N in the Whittle Burn at Ovingham .............. 23 Figure 3.3 Concentrations of nitrate-N in Coldicoate Burn, Ponteland ................. 24 Figure 3.4 Concentrations of nitrate-N in the River Pont at Kirkley Mill ................ 24 Figure 3.5 Concentrations of IPU in the five reservoirs at Whittle Dene 2002 .........

(Source: NWL)..................................................................................... 26 Figure 3.6 Flow (L sec-1) and rainfall (mm) at Whittle Dene 2003......................... 27 Figure 3.7 Flow (L sec-1) and rainfall (mm) at Whittle Dene 2004......................... 28 Figure 3.8. Concentrations (µg L-1) of IPU at Whittle Dene 2002 – 2004............... 29 Figure 3.9 Loads of IPU at Whittle Dene 2003-2004 (mg).................................... 30 Figure 3.10 Concentrations (µg L-1) of propyzamide at Whittle Dene 2002 – 04 .... 31

Figure 3.11 Concentration of faecal coliforms at Whittle Dene 2002 – 2004 .............

(log scale) (CFU/100 ml) ..................................................................... 32 Figure 3.12 Concentration of nitrate-N (mg L-1) at Whittle Dene 2002 – 2004........ 33 Figure 3.13 Loads of nitrate-N at Whittle Dene 2003-2004 (kg) ............................. 34 Figure 3.14 Concentration of MRP at Whittle Dene 2002 – 2004 (µg L-1) ............. 34 Figure 3.15 Concentration of TP at Whittle Dene 2002 – 2004 (µg L-1).................. 35 Figure 3.16 Concentration of suspended sediment at Whittle Dene 2002 – 2004

(mg L-1) ................................................................................................ 35 Figure 3.17 Loads of TP at Whittle Dene (kg)........................................................... 36 Figure 3.18 Loads of MRP at Whittle Dene (g) ......................................................... 37 Figure 3.19 SMN autumn 2002............................................................................... 38 Figure 3.20 SMN autumn 2003............................................................................... 38 Figure 3.21 SMN autumn 2004............................................................................... 39 Figure 3.22 P index (Olsens) and cropping spring 2003......................................... 40 Figure 3.23 Soils at Whittle Dene ........................................................................... 41 Figure 3.24 Dominant soil series in the area around Whittle Dene......................... 41 Figure 3.25 Agricultural field drainage in the Alnwick Division 1951 to 1991.......... 42 Figure 3.27 Flow accumulation map for field number ‘F9’ and photographs .......... 45 Figure 4.1 Average arable area (%) in parishes around the Whittle Dene Western

Catchment 1970 – 2000 ...................................................................... 51 Figure 4.2 Predicted risk of IPU leaching to watercourses in an average autumn 52 Figure 4.3 Ten most frequently occuring substances in surface water >0.1 µg L

(EA 2003)-1

............................................................................................ 53Figure 4.4 Map of main sources of faecal material at Whittle Dene...................... 58 Figure 4.5 Faecal Coliform: Faecal Streptococci Ratio at Whittle Dene 2004 ...... 59 Figure 4.6 Predicted loss of nitrate (kg NO3-N) in an average year...................... 61 Figure 4.7 Concentration of TP (µg L-1) vs total daily flow (m3 day-1) .................. 64 Figure 4.8 Risk of soil erosion by water in an average year around Whittle Dene 66 Figure 5.1 Proportionate Change in Total Subsidy Receipts by Farm Type ......... 76 Figure 5.2 Risk of soil erosion by water in an average year around Whittle Dene 78 Table of Plates Plate 2.1 Water sampling equipment and telemetry ........................................... 10 Plate 3.1 Aqueduct at Whittle Dene .................................................................... 20 Plate 3.2 Whittle Burn entering the reservoir complex........................................ 22 Plate 4.1 Soil erosion and poor drainage at Whittle Dene 68 Plate 4.2 Field drain blocked by Willow roots (photo from outside catchment) 68

ACKNOWLEDGEMENTS This research was funded by Defra, with contributions by the Environment Agency, United Kingdom Water Industry Research and the Voluntary Initiative. The support of Northumbrian Water Ltd and the National Farmers Union is also appreciated.

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EXECUTIVE SUMMARY Background Implementation of the Water Framework Directive (2000/60/EC) brings with it many challenges. These include developing methods for identifying diffuse pollution sources at the catchment scale, identifying appropriate mitigation measures to decrease pollution, devising appropriate instruments to encourage their uptake and engaging land managers and other stakeholders in the process. A further complication is that it is necessary to control several potential sources of pollution, which may provide conflict when identifying mitigation methods. This project aims to address these challenges in a small (c. 3.9 km2) catchment, the Whittle Dene Western Catchment (WDWC), Northumberland. The advantage of using a small, well-defined catchment is that it allows a complete understanding of sources and causes of pollution, so that there is a much better chance of being able to effect change. The catchment therefore represents an ‘idealised’ situation in which to characterise, monitor, formulate and implement a plan and to assess results in a formal, scientific manner. The WDWC was deemed suitable for study following a scoping study of the area (Hillman et al., 2002). It is a rural catchment and is integral to the transfer of water to a series of 19th Century reservoirs supplying Newcastle and its surrounding areas (estimated 600,000 consumers, NWL, pers comm). The Scoping Study concluded that, within a five-year timeframe, an integrated catchment management plan should be implemented, which would take account of water quality issues while promoting sustainable agriculture with biodiversity and amenity benefits. Given the size of the research catchment (c. 3.9 km2), the project has taken care to ensure that its characteristics are representative of the region and therefore an exercise was conducted to investigate land use and water quality in a larger area. The investigations were, therefore, conducted at three scales:

• The wider catchment (c. 500 km2), incorporating existing water quality data, land use, land cover, soil type, and screening models for diffuse pollution risk.

• The Whittle Dene Western Catchment (WDWC) (3.9 km2), detailed monitoring and investigations to identify the sources and transport of diffuse pollutants and their causes.

• Individual fields assessed for soil nutrients and physical condition, drainage, field management, animal husbandry.

The project provided an approach to help identify and address water quality issues in a predominantly rural catchment, which could be transferable to other catchments. This falls within Defra’s objectives of minimising loss of potential pollutants from agricultural activity to the wider environment: in this case, the water environment. It is also directly relevant to the implementation of the Water Framework Directive. Methods A Steering Group comprising Defra, EA, ADAS, Voluntary Initiative, Northumbrian Water Ltd and the NFU guided the project, with a funded research student at the University of Newcastle. Monitoring and catchment characterisation under Phase I ran from January 2003 to December 2004. Watercourses in the WDWC were instrumented at strategic locations using flow-gauging structures, automatic water sampling equipment and telemetry. Water samples

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were collected at regular intervals during baseflow and high flow (storm events) to be analysed for selected pesticides, faecal indicator organisms (FIOs), nutrients (nitrate, phosphorus) and suspended sediment. Fields in the catchment were sampled to 90 cm for determination of soil mineral nitrogen (SMN) each autumn. Further soil samples were taken in spring 2002 for determination of Olsen P, K, Mg and pH. Catchment characterisation included a survey of soil type, soil structure, field drainage, aquatic invertebrates and macrophytes, farm assessment and management of individual fields. Supporting data was used for a wider area (c. 500 km2) to assess water quality and risk of diffuse pollution. Historical water quality data was used alongside agricultural census data, land use and soil type. Data on the drainage installations that took place from the 1950s to the 1990s was collected by the former MAFF Divisional Offices. ADAS collated these databases and they were interrogated to indicate the likely extent and nature of the underdrainage systems in the area. Diffuse pollution risk assessment models were run for the agricultural herbicide isoproturon, nitrate and sediment. Results and discussion Rainfall and flow The total annual rainfall in 2003 was 39% below average, with a very dry autumn. This caused minimal flow throughout much of the summer and autumn. Conversely, 2004 had 113% of average rainfall, with a particularly wet summer, causing a peak flow of over 1200 L sec-1 in August in the Whittle Burn. The catchment hydrology was dominated by a flashy hydrograph with low baseflow, common for headwater catchments with relatively impervious soils and geology. Pesticides Between 2003 and 2004, concentrations of the agricultural cereal herbicide IPU regularly exceeded the 0.1 µg L-1 limit for an individual pesticide in water, with peak concentrations exceeding 2.0 µg IPU L-1 during the spring and autumn spraying seasons. However, in January 2005, following a wet winter, concentrations of IPU peaked at 10.0 µg L-1. Modelling predicted that approximately 170 km2 of an area of 500 km2 around the WDWC was at high risk of IPU losses in an average autumn. Another herbicide, propyzamide, was detected at concentrations >0.1 µg L-1 during the spraying season and this was used on oilseed rape. There were isolated detections of the insecticide cypermethrin. The peak concentration was 0.19 µg L-1, compared to an EQS MAC of 0.002 µg L-1 and this was shortly after cypermethrin was applied to a cereal crop. Cypermethrin is strongly adsorbed by soil particles and has a low solubility. The sorption of synthetic pyrethroids (SPs) to soil does not, however, discount their movement either through macropores down the soil profile or their entry into surface waters, whilst attached to soil particles. The Brickfield and Dunkeswick soils of the Western subcatchment are prone to cracking and, following the very dry summer and autumn of 2003, macropore flow is likely to have been significant Current national monitoring programmes will not detect such localised, but potentially important, concentrations in small streams and tributaries. Monthly monitoring of higher order streams is unlikely to detect such incidents, and it could be argued that the impact on

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headwater stream, small tributaries and their ecology in the semi uplands could be disproportionally high. Faecal indicator organisms The concentrations of FIOs showed a typical seasonal pattern, with concentrations of faecal coliforms rising from <10 cfu/100 ml in winter to c. 100,000 cfu/100ml in late summer. This pattern was related to changes in the long term store of bacteria in the soil, and this in turn was related to changes in factors such as frequency and amount of rainfall, and increased animal grazing in the spring and summer. Several high-risk areas were identified, such as unfenced watercourses, seasonally wet depressions in fields, grassland over historical field drains (cundys) and purpose built stock watering locations on the banks of the Whittle Burn. These were areas that allowed stock to water from a wet depression, while preventing direct access to the channel. There are no specific pieces of legislation that specify or advise the concentrations of FIOs that should be sought in small headwater streams or rivers. However, the respective values specified by both the Surface Water Abstraction Directive (75/440/EEC) and the Bathing Water Directive (76/160/EC) were exceeded for several months of each year. Nitrate The Surface Water Directive, 75/440/EEC, (CEC, 1975) specifies a mandatory limit of 11.3 mg NO3-N L-1 (50 mg NO3 L-1) in surface waters. In 2003, the concentrations in the main stream typically remained <5.0 mg NO3-N L-1 until late winter, and this was due to the very dry autumn, which caused nitrate to remain in the soil profile. It is also possible that the exceptionally dry conditions inhibited mineralisation of organic N, thereby reducing the amount of nitrate in the soil. The advent of the late winter rains caused the concentrations in the main stream to exceed 25 mg NO3-N L-1 as nitrate was leached from the soil in December 2003. There were also peaks up to 34 mg NO3-N L-1 in drain D3. . The drain at D3 is strongly suspected as taking domestic drainage (potentially from a septic tank), before running through an arable field to the sampling point. The most significant factor in 2004 was the above average rainfall from June to August, and, in particular, the heavy rainfall in August was responsible for significant summer losses of nitrate. Phosphorus and sediment The concentrations of Molybdate Reactive Phosphorus (MRP) in the Whittle Burn and feeder ditches exceeded 100 µg L-1 during low flow, and after heavy rainfall. Concentrations tended to increase as flow decreased in summer 2003, and this was probably due to reduced dilution. In common with nitrate, concentrations of MRP increased in December 2003 after a very dry autumn and peaked at >100 µg L-1 at site F3. In 2004, the peak concentrations occurred in August as a result of the above average summer rainfall. As outlined in Section 3.4, some of these storms were particularly heavy, and were responsible for mobilising significant quantities of Total Phosphorus (TP) and sediment with the largest concentrations at gauging station F2, when peak discharge exceed 1200 L sec-1. Aquatic ecology and vegetation The vegetation assessment suggested that most of the aquatic species would survive under eutrophic (high nutrient) conditions. Only Glyceria fluitans, which is described as mainly mesotrophic, is the exception. None of the species would be found in only oligotrophic (low

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nutrient) conditions, however. This assessment supports the findings of the water quality monitoring survey and the modelling results. The surveys of aquatic invertebrates revealed that there was a rich community of aquatic macro-invertebrates in the Whittle Burn, contributing to the aquatic biodiversity of the Whittle Dene catchment. Some 17 of 41 families were present with BMWP scores ≥ 6 indicating water of relatively good quality. However, biotic indices were initially developed for considering organic pollution such as sewage and not agrochemical impacts. Land use change and water quality The shift towards more arable land in a northerly direction from the Tyne Valley was very apparent. In the WDWC, the proportion of arable land increased by up to 40% in the thirty years analysed and the increase was particularly apparent between 1980 and 1995. However, it cannot be assumed that the relationship between arable conversion and a perceived decline in water quality is straightforward. Detailed catchment investigations, such as that in the WDWC, are necessary to understand the causes. Discussion Rainfall and flow Rainfall was a large factor in variations of water quality. There was little dilution during the dry conditions in 2003 and this caused a uniformly large concentration of FIOs and MRP, for example. This was mainly ascribed to direct access of the burn by livestock. By contrast, the large amounts of summer rain in 2004 caused significant transport and mobilisation of sediment, FIOs and nitrate, contributing to both large concentrations and loadings. Soils and drainage It is considered that soils and drainage contribute significantly to the risk of diffuse pesticide losses to watercourses at Whittle Dene. Soils have a major physical influence on hydrological processes. Their physical properties govern the storage and transmission of water within the soil, and these properties combine with other characteristics to act as chemical buffers and biological filters to a greater or lesser extent. Though some of these effects can be observed at a very small scale, their influence can become pronounced when aggregated across the whole of the catchment. Brickfield is the main soil series of three that occur within the WDWC. Brickfield soils are graded 3b for agricultural land classification purposes and soil wetness is the main limitation. Underdrainage systems in the WDWC were found to be in a poor condition. The ADAS drainage database revealed that over 80% of drainage schemes are not recorded as using proper permeable fill (such as gravel) to cover the pipes in the drainage trenches, and the majority of the schemes did not employ secondary treatments, such as subsoiling. The general lack of permeable fill in the drainage trenches, together with an absence of secondary treatments, will have the effect over time of decreasing the overall drainage effectiveness. More water will tend to remain either on or within the shallow plough layer, especially if it is at all smeared at its base following cultivations. Overland and near surface flow would become the dominant flow paths and pollutants will be transported with the water moving along these paths. The effectiveness of drainage systems relies not only on the in-field soil conditions and pipe condition, but also on effective drainage outfalls to allow sufficient headfall. Visual examination of the ditches within the WDWC showed that in places there is an urgent need for maintenance and clearance.

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Under less effective drainage conditions, there will be a tendency in all winters to return to field capacity earlier, resulting in potentially more difficult soil management conditions and increased difficulties for the application of autumn pesticides and early spring fertilisers. Pesticides There is no evidence that farmers are using pesticides irresponsibly or against recommendations. However, the use of some marginal fields for arable production could be questioned. This is not unique to Whittle Dene, and poor grade agricultural land is frequently used for arable production despite limitations due to drainage, soil characteristics, or slope, for example. Under these conditions, a factor in the success of ES might be how many of these fields are reverted to permanent, low input grassland. The majority of pesticide mixing and handling is conducted outside of the monitored area of the WDWC. Thus, in this case, diffuse sources from arable land are the main source of pesticides to watercourses. Water quality monitoring has revealed concentrations of arable pesticides across the WDWC; i.e. no single field was responsible. Pesticides in water bodies are a national issue. Pesticide mixing handling areas can be a significant source of water pollution in addition to diffuse sources (e.g. Mason et al., 1999), therefore it is important not to neglect this source when discussing water quality with farmers in the catchment. Pathogens Several studies have identified domesticated farm animals as a source of faecal organisms to watercourses and, in particular, bathing waters in the UK, e.g. Aitkin et al., (2001). There are relatively few studies that have measured concentrations of faecal indicators in headwater streams, and even less over successive seasons. However, it is important to investigate the source and transport of faecal material to watercourses in order to devise management strategies to protect amenity and bathing waters. Potential source areas such as the WDWC represent an important avenue of investigation, as there are no significant sources beyond domestic and wild animals to complicate the situation. Between 2003 and 2005, organic fertiliser was used relatively infrequently to a small number of fields. The solid, relatively well-stored manure is likely to have presented less risk of pathogen transport to watercourses than slurry (Nicholson et al., 2000). Information on farm and field management, animal movements and field walking was used to identify several sites that were considered ‘high risk’. Most of these could be tackled relatively easily by fencing, tracks and cattle bridges. Some were more problematical, such as several seasonally wet depressions in fields, cracking soils over old stone drainage systems. Nitrate Historical data on nitrate in the watercourses around Whittle Dene showed the usual seasonal trends, with larger concentrations in autumn and winter (e.g. Davies, 2000). The concentrations of nitrate in spot samples from rivers and streams in the area exceeded the 11.3 mg NO3-N L-1 limit in autumn and winter in the 1990s. These concentrations are likely to be less than the actual peaks because they were ‘spot’ samples, taken by hand at a low sampling frequency without consideration of flow conditions. The reduction in concentrations in nitrate during 2000 – 2002 compared to previous years was of particular interest. This was ascribed to dilution during the very wet autumn of 2000, and to destocking/manure spreading restrictions during Foot and Mouth Disease.

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At Whittle Dene, there were large concentrations of mineral N in fields in autumn, indicating that there is considerable scope to reduce inputs of N across the catchment. This was confirmed by assessing fertiliser policy for the farms. It is important to ensure that fertiliser use is matched closely to crop requirement and expected yield and this should be viewed holistically to include factors which adversely affect crop health, such as soil conditions and drainage, for example. Phosphorus and sediment There are several sources of MRP, sediment and particulate-P in the WDWC. These include runoff from poorly drained fields, sediment from arable field drains, trackways for livestock that slope to the Burn, livestock farm hardstandings, and runoff from roads and verges via drains. Cattle can be seen to be watering directly from the Burn with the usual problems of direct daefication to the water, puddling the bed and banks. In high flow, there will be unconsolidated bed sediment and organic material that will become suspended and entrained in the current. There are reports that the Whittle Burn has become silted in recent years. This has coincided with both an increased arable area and the felling of a small block of woodland (with associated bare soil). Woodland and forestry operations can be a significant source of sediment to watercourses (e.g. Stott and Mount, 2004). Forest and Water Guidelines (Forestry Commission, 2003) should minimise water quality problems as a result of forestry operations, and it will be important to work with managers of small blocks of commercial woodland, such as that found in the WDWC. Catchment response Resources for catchment management of diffuse pollution are likely to dictate that detailed investigations are limited to specific, problematic areas. Phase I has shown how intensive investigations can successfully identify the sources and causes of water quality issues in small catchments, but this is clearly not practical without a method for identifying these areas. Models and local knowledge were used to indicate the situation in the environs around Whittle Dene, and such information is useful to target specific areas for study. Models were useful for screening large areas, but Phase I also showed that the issues responsible were often beyond the designed capabilities of the software. For example, underdrainage maintenance, or livestock watering from the Burn had a large effect on several water quality parameters, but this level of detail is generally not possible to include in modelling. The results show that models are useful in guiding attention, but there is still a considerable amount of investigative work required before solutions can be tailored to the locality. The project has clearly shown that water quality is insufficiently studied at the small catchment scale where factors beyond strict scientific principles on losses of nutrients, FIO’s or pesticide substances from agricultural systems come into play. Farm management, diversification, economics, domestic dwellings, historical land drainage, and catchment physical characteristics are all complicating factors. By undertaking detailed studies, the project is now in an excellent position to put forward a response in the form of a catchment plan. It is proposed to continue to monitor the WDWC during and after the introduction of the Single Farm Payment (SFP) and the land management that it requires under Cross Compliance (XC). In addition, it is intended to make best use of the new Environmental Stewardship schemes to improve water quality. However, it is acknowledged that some additional action may be desirable at Whittle Dene in order to address some specific problems, therefore some additional work and capital schemes are also proposed. All these options have been put forward as a plan to improve the water quality at Whittle Dene.

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The GAEC requirements for soils are detailed in Defra (2005b). The intention is for all farmers to draft a risk-based soil management plan for introduction from 2007 onwards. There are therefore two years for familiarisation of the guidelines and drafting of the plan, prior to implementation. The guidelines for ‘heavy soils’ are particularly relevant to the area around Whittle Dene. Amongst the principles of good soil husbandry for heavy soils are those for effective underdrainage systems and regular maintenance of field drains and ditches. These aspects need especial attention at Whittle Dene. There are three distinct farm types in the Western Catchment, with four other landowners with fields in the catchment, but holdings outside. The implementation of voluntary schemes allows different interpretations and options. As already mentioned, there are many options under ELS/HLS and the project needs to ensure that these are selected carefully for each farm. The relevant technical specialists will liase with the farm consultant, farmer and landowner, to advise what options are desirable. A summary of water quality results from Phase I may help convince farmers of specific options if there is difficulty. ELS The intention is to work with the farmers to produce the best combination of options, primarily to manage agricultural inputs to watercourses, with secondary landscape and wildlife benefits. The key components are listed and outlined below.

• Buffer strip along the burns and ditches in arable fields: the efficacy of this option to control soluble diffuse pollutants is questionable, but they are likely to have an impact on sediment, and sediment bound substances. Buffer strips may also reduce the risk of spray drift under some circumstances.

• Ditch maintenance at the head of the burn: will improve habitats and improve drain

outfalls, potentially improving in-field drainage and allowing increased infiltration (free-flowing drains have been shown to reduce IPU losses on this soil type for this reason). The effect of drain improvement on the transport of other potential diffuse pollutants (e.g. N, P) in the Whittle Dene research catchment will be important to monitor.

• Low input grassland adjoining the burn: will reduce potential losses of nitrate

• Two key field corners out of production:

• seasonally wet area of grass field on margin of burn that is currently used for stock watering;

• a difficult arable field corner that is close to two large open field drains.

• Soil management plan. • Crop protection management plan. • Nutrient management plan.

Each of the above plans will be beneficial in encouraging profitable husbandry while in addition reducing the possibility of unnecessary inputs, reducing the risk of losses to watercourse and improving understanding of the relationship between land management and the aquatic environment. A detailed and integrated soil, nutrient, manure (where applicable) and crop protection management plan would be ideal for farms in the catchment.

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These options will have an as-yet unknown impact on water quality in the WDWC. Supplementary options to benefit the water environment, such as the proposed Higher Level Scheme, could be deployed and evaluated at Whittle Dene. Since membership of the ELS is a prerequisite for the HLS, the implementation (or trial) of options under this scheme could be staged beyond 2005. Indications are that Whittle Dene will not be eligible under the HLS. It would be interesting to discuss if options to protect key water supply catchments (i.e. intended for abstraction for potable use) could be deployed. The area around Whittle Dene shows how important this is, since the water company and EA have no effective mechanism to interact with farm decisions on ‘high risk’ farms and fields. Similar ADAS work in the Coquet (also in Northumberland) has also identified that key parts of the catchment could be targeted to protect water resources. It would be possible (and perhaps preferable) to discuss this as the project progresses, as a way to ‘ratchet-up’ the options through time. A range of options such as fencing or cattle bridges should be deployed with relative ease by the farmer (at quiet times of the year) or by a contractor. The project has identified several potential contractors in the area, and has experience with some of them during work for Phase I. The contractors are, therefore, trusted local companies with a good knowledge of the area and of the Whittle Dene project. In practice, these options should be planned in the winter of 2005, ready for installation in the spring and summer. The implementation of voluntary capital schemes will require careful consideration. The plan has identified what problems need to be addressed, the response and location, but a detailed plan of work is now needed for each option. ADAS is able to call on relevant specialists to plan such schemes, which include drainage remediation schemes and dirty water systems, for example. In common with the options recommended under the agri-environment schemes, these options will be planned carefully with the farmer in winter 2005, ready for installation in spring and summer. Drainage in arable fields at Shildonhill Farm is poor. Evidence suggests that a gas pipeline installed in the 1980’s caused significant drainage problems. There is a spring running across grass and arable fields to the Whittle Burn which causes significant soil erosion and crop failure. It is very unlikely that agricultural inputs are suspended where there is no crop, thus creating a significant potential source of pesticides and nutrients to the burn. Options here include drainage remediation, or reversion to low-input grassland under ELS, for example. The ‘Military Road’ (B6318) includes drains which run into the catchment. There is little problem where this occurs through open ditches. However, it is noticeable that the road drainage runs past the livestock unit at Vallum Farm where there is significant potential movement of faecal material. The road drainage should be diverted at this point to reduce the risk of farm runoff. The yard at Vallum Farm drains towards the Vallum Runner ditch, which joins the Whittle Burn. Samples from this point have indicated high concentrations of faecal material, nutrients and pesticides, and while not all will emanate from the yard, it still represents a significant potential source. The runoff from this yard should be either stored or treated. Options include a dirty water holding tank, or a constructed sedimentation pond. Runoff from pesticide mixing and handling areas has been shown to be a significant potential source of pesticides to drains and ultimately watercourses. Biobeds have the potential to reduce the risk of pesticides entering watercourses from pesticide handling areas. ADAS activity at Whittle Dene and the 500 km2 Coquet Catchment has revealed that farmers and pesticide users are very interested in this new technology. Farmers are, however, very conservative and are often led by their peers. A demonstration biobed at Whittle Dene would be an extremely valuable educational tool for the North East and is totally conducive to the

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theme of work at Whittle Dene. Ultimately, the catchment could be used as an educational facility and this demo unit would therefore be seen by a large number of relevant stakeholders. Fencing and bridging is needed for many fields. Fencing stream banks restricts livestock access, and reduces the risk of faecal material entering the watercourse. Similarly, where access is across watercourses, it is highly desirable to construct a bridge to prevent direct defecation into the stream. Much of the watercourses at Whittle Dene need fencing at one point or another, to prevent livestock access. Since the burn is commonly used as a watering point for livestock, it will also be necessary to install a water supply for fields used for grazing. ADAS ecological surveys, conducted as part of the Whittle Dene Project, supports earlier findings that the burn contains undesirable quantities of sediment. The main sources of the sediment are likely to be from arable fields at Shildonhill, and also a small woodland plantation felled in the early 1990’s. The stand at Shildonhill is likely to be felled during the life of the project. Plantations <10 ha are common in the North East, usually on unproductive or sloping land that can be vulnerable to erosion. It is recommended that dialogue continues with the landowner and Forest Enterprise. Low cost options may be appropriate under these circumstances and may be more effective than equivalent use in larger forest plantations. WDWC and the Voluntary Initiative on Pesticides Whittle Dene has been included as part of the Voluntary Initiative on Pesticides. The catchment is unusual in that it is the only one not to have any VI activities implemented, the plan being to collect baseline information on water quality and pesticide use. After discussion with the VI and NFU, the component parts of the VI which are considered to be most successful will be deployed to the Whittle Dene catchment. Thus, the catchment will benefit from experiences of other catchments collected over the past two years. The catchment will benefit from the introduction of VI Crop Protection Management Planning, for example. The farmers and contractors in the catchment are well aware of the VI. The objective for Phase II will be to ensure that the farms and spray contractors who operate in the catchment have taken part in the main components of the VI. For example, the project will work with spray operators to persuade them to take part in the National Sprayer Testing Scheme. It is important to use the Whittle Dene catchment to its greatest potential. The issues at Whittle Dene are not unique, and the catchment is representative of a large area of North-East England. Farmers are naturally conservative, and respond well to practical demonstrations. The catchment will therefore be used as a demonstration facility for local, national and international visitor. Occasional factsheets will be drafted the project to explain the background, methods and results. ADAS has worked on similar issues in the 500 km2 Coquet Catchment and it is apparent that key areas of the Coquet are responsible for most of the pesticide water quality problems in the river. These areas have similar characteristics and soils to those at Whittle Dene. Thus, the demonstration facility will be important to regional environmental and economic targets.

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LIST OF DEFINITIONS, ACRONYMS AND ABBREVIATIONS ADAS: ADAS consulting Ltd. CAP: Common Agricultural Policy CFU: Colony Forming Unit CSF: Catchment Sensitive Farming CSS: Countryside Stewardship Scheme XC: Cross Compliance Defra: Department for environment, food and rural affairs ESA: Environmentally Sensitive Area EN: English Nature DWI: Drinking Water Inspectorate DWPA: diffuse water pollution from agriculture EAA: European Environment Agency EA: Environment Agency ES: Environmental Stewardship FMD: Foot and Mouth Disease GAEC: good agricultural and environmental condition GAC: granular activated carbon GC-MS: gas chromatography mass-spectrometry GPS: Global Positioning System Grab sample: water sample taken by hand, sometimes also called ‘spot’ sample HPLC: high performance liquid chromatography (formally high pressure liquid chromatography) Measure: individual option to improve water quality. Can be source, transport, or field edge (e.g. reduced fertiliser application, contour ploughing or buffer strip, respectively) Microcatchment: small surface water catchment (usually between 1 and 10km2) used for detailed water quality and/or quantity studies MRP: molybdate reactive phosphorus NFU: National Farmers Union

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NSRI: National Soil Resources Institute NVZ: nitrate vulnerable zone NWL: Northumbrian Water Ltd Instrument: the method used to promote the implementation of a measure (e.g. tax, education/advice, grant aid) PAC: powdered activated carbon p.f.: permeable fill RAP: Regional Area Payment SDA: Severely Disadvantaged Area SFP: Single Farm Payment SMN: soil mineral nitrogen SMR: Statutory Management Requirements STW: sewage treatment works TDP: total dissolved phosphorus TP: total phosphorus VI: Voluntary Initiative WFD: Water Framework Directive WTW: water treatment works UKWIR: United Kingdom Water Industry Research WDWC: Whittle Dene Western Catchment

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1. INTRODUCTION

Both quantity and quality of the water resource are linked to land management, but there are technical, financial and institutional reasons why the interests of water resource planners and farmers have often been in conflict. The Water Framework Directive (2000/60/EC) (WFD) requires all bodies of water within designated ‘River Basins’ to be characterised, and Management Plans must be implemented for each River Basin District to ensure that all water bodies meet specified chemical and ecological standards for their specified use. Thus, there will be an even greater emphasis placed on land management and its effects on the water resource. Implementation of the WFD brings with it many challenges. These include developing methods for identifying diffuse pollution sources at the catchment scale, identifying appropriate mitigation measures to decrease pollution and engaging land managers and other stakeholders in the process. A further complication is that it is necessary to control several potential sources of pollution, which may provide conflict when identifying mitigation methods. Catchment planning can be split into a number of idealised, logical steps, and these are listed below.

1. Identify the catchment 2. Characterise the catchment using existing data and information 3. Devise additional monitoring as required 4. Identify the environmental stresses 5. Identify appropriate measures to improve standards and the instruments with which to introduce them 6. Ensure that measures and instruments are introduced as a coherent plan with due regard to other sectors 7. Monitor 8. Review and revise methods, measures and the catchment plan (Modified from Willett and Porter, 2001)

The purpose of this report is to describe the approaches taken to fully characterise and monitor a small, predominantly agricultural, catchment. The general data, information and models that could be used as a screening exercise for larger a catchment area will also be described using the Whittle Dene area as a practical example. Finally, a pragmatic response to water quality problems, in the form of a catchment plan, will be described. It is proposed to implement the plan from 2005 onwards, with associated monitoring. The catchment plan described in this document is not intended to devise new and novel measures to control diffuse pollution, but to take new schemes to see how they will operate ‘on the ground’. Similarly, it is not the intention of this report to review diffuse pollution in England and Wales as such reviews have recently been published elsewhere (e.g Defra 2002a, 2004a). That said, where it is appropriate a brief outline of current understanding or key research findings will be presented where appropriate. 1.1 Water quality and the WFD Water pollution is usually divided into point source, or diffuse (non-point). Point source pollution is defined by the European Environment Agency as ‘a stationary location or fixed facility from which pollutants are discharged; any single identifiable source of pollution; e.g. a pipe, ditch, ship, ore pit, factory smokestack.’ These discharges are usually relatively straightforward to manage. In recent decades there have been significant reductions from a range of point sources to water such as utilities (e.g. STWs), industry and agriculture (e.g. slurry stores). However, there is still an underlying water quality problem in many parts of the UK, and this situation is repeated internationally in developed countries.

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While point source pollution of watercourses is relatively well understood and regulated, there is an underlying problem of poor water quality from some rural and urban areas. This is in the form of diffuse pollution (i.e. without a single point of origin or not introduced into a receiving stream from a specific outlet). Individually, these discharges are usually insignificant, but cumulatively, they can cause water quality problems. However, the issues are not evenly distributed, either spatially, or temporally, and herein lie the many problems with their management:

• Locating high risk areas of diffuse pollution in catchments • Devising suitable monitoring programmes within constraints of available resources • Identifying the pollutants • Identifying the reasons • Identifying solutions

The need to improve water quality, largely in response to the WFD, has increased the need for methods to screen large areas for risk of diffuse pollution. However, the monitoring of large areas at sufficient spatial and temporal resolution to identify high-risk areas in large catchments is prohibitively expensive in time and resources. In recent years, advances in GIS, data management and modelling have largely fulfilled this need, with output from desk exercises identifying areas on which to focus study, or attention. Usually, these data have limitations and are used to assist in planning a more intensive investigation, in which limited resources can be focussed and a monitoring plan devised. The requirements for the design of surface water monitoring programmes under the WFD illustrate the move away from the former static protocols implicit in the old directives to a more dynamic, risk-based approach. Here pressures due to hydromorphological and physico-chemical factors are linked to biological indicators of environmental quality. However, these biological indicators have yet to be fully defined. Under the WFD, a network of monitoring sites needs to be established to classify all water bodies using a combination of surveillance, operational and investigative monitoring of proscribed quality elements. In England and Wales, there is already a good monitoring network, but it is inadequate for the purposes of diffuse pollution. The EA assesses the quality of rivers and canals by looking at nutrients, chemistry, and biology. Approximately 7,000 river and canal sites are sampled for several parameters (e.g. N, P, pH, conductivity, metals) but these will vary between sites. This sampling network developed gradually, primarily to monitor point sources, so the sampling parameters are targeted and sampling frequency varies by site (maximum monthly). Additionally, the sampling is conducted by taking ‘grab’ samples at set frequency with no regard to flow and, since concentrations of diffuse pollutants are largely dependant on flow conditions, it is important both to measure discharge, and to take samples or measure concentrations automatically during rainfall/storm events. Thus, while a useful programme to collect data on the impacts of point sources, the current monitoring programme is not adequate to monitor the impacts from diffuse sources. Essentially, surveillance monitoring will be used to validate risk assessments and determine long-term changes. Operational monitoring will be used to determine the status of water bodies identified as being at risk and how this changes as result of the programme of measures. Investigative monitoring will be used to establish reasons for failure. The building of the monitoring network will be influenced by the nature of the individual water bodies, the analysis of the pressures and risks associated with them, the classification system to be applied and the extent of the existing monitoring network.

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It is likely that the need to introduce monitoring schemes for diffuse sources of water pollution will make small, representative catchments very desirable. Thus, research projects such as Whittle Dene will provide very useful information on the use of such ‘subcatchments’, in addition to the actual data that they can provide. 1.2 Whittle Dene project description The Whittle Dene system comprises five interconnected reservoirs and this system is fully described in Section 3. Briefly, water is supplied to the system from a combination of direct catchments, and from larger impounding reservoirs via open aqueducts. There have been water quality problems in the reservoirs, largely from agricultural herbicides, but also nutrients. One of these catchments, the Whittle Dene Western Catchment (WDWC) was historically used to supply one of the Whittle Dene supply reservoirs, the Western Reservoir, but the Whittle Burn was diverted around the reservoir complex in 2001. A Scoping Study was conducted to assess the suitability of using the catchment for a research project. Hillman et al. (2001) concluded that due to the small size (c. 3.9 km2) and characteristics of the WDWC it was ideally suited to a comprehensive study on the interactions between water quality and land management. In 2002, a comprehensive monitoring programme was put in place and a response, in the form of a catchment plan was devised. The methods and results are reported in this document. Tasks included instrumentation of the catchment to take water samples automatically during storm events and during baseflow, survey/monitoring of soil and water status, farmer engagement and farm survey (Section 2). This phase of the work ran to December 2004. The monitoring and characterisation period enabled a good understanding of the water quality problems (Section 3) and the reasons for them (Section 4). It also allowed a response to be drafted with a reasonable degree of confidence of addressing some of the causes, and not simply the symptoms, of water quality problems in the catchment. The response takes the form of individual measures designed to address specific problems (e.g. a buffer strip). The measures were incorporated into a coherent catchment plan with due regard to other issues (e.g. wildlife, habitats, flooding). Allied to this process, it was crucial to take instruments of delivery into account, which will take the form of either ‘sticks’ (e.g. legislation, taxes) or ‘carrots’ (e.g. grants, advisory schemes) (Section 5). Many of the water quality monitoring and catchment assessments described here are resource intensive, since they were designed to be employed in a small research catchment. This is because the detailed data on the main diffuse pollutants (pesticides, N, P, sediment, faecal indicators) and the sources/transport processes (land use, land management and characteristics) can only be effectively collected at a small catchment scale. However, the response, in the form of a catchment plan, was designed to be pragmatic and responsive to current agricultural practices and support schemes. New or novel measures and instruments were not considered since these need to be studied at a smaller (usually field) scale to evaluate their effectiveness. Thus, the Whittle Dene project aims to take forward the scaling issue from field to small catchment to monitor the effect of a combination of current measures and best practices. Only at this scale will the ultimate success of catchment planning be truly assessed, since complications at a larger scale will make such assessments extremely difficult. It is also true that screening processes are likely to show discrete, high-risk subcatchment areas within catchments, such as the WDWC. This is especially so for resource protection areas, such as agricultural land surrounding reservoirs, or close to an abstraction point for drinking water on a river, for example. Therefore this project is of direct relevance to policy

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and scientific research, for several reasons. First, to provide a description of approaches in catchment management, second, to detail comprehensive catchment information and water quality data for successive years; lastly, to test the feasibility of implementing a catchment plan for resource protection. Given the size of the research catchment (c. 3.9 km2), the project has taken care to ensure that its characteristics are representative of a much wider area. Supporting desk-based soil mapping, modelling studies, agricultural census data and existing water quality data have been used in conjunction with tasks in the research catchment to ensure, as far as reasonably possible, that this is the case. These approaches are consistent with screening large areas for risks of diffuse pollution. While there are many catchment projects working on water quality in rural areas across the UK, few undertake detailed monitoring. Where monitoring is undertaken, it is usually for individual parameters to support specific studies on nitrate, phosphorus, or sanitary indicators, for example. In a review of activity to reduce diffuse water pollution from agriculture in priority catchments, Humphrey et al. (2005) considered that there was a range of disparate projects. Many of these projects conducted practical extension work with the rural and agricultural community, but scientific data to support the projects was usually not integral to the work. There has been a continued research programme into individual water quality issues such as nitrates, pesticides or pathogens. Typically, management and technical methods have been developed to improve water quality, and these have been researched at the field and small catchment scale. However, rarely will only one parameter be considered in the real world. Usually there will be several issues that need to be addressed. There has been little work to consider how such measures interact when implemented at the catchment scale, yet this is important, since there are many complications between field and catchment scale. Notable exceptions include ‘The Tarland Catchment Initiative’, which is funded through the North Sea Commission Interreg programme. The Tarland Catchment is the most westerly tributary of the River Dee, N.E. Scotland in which intensive land management dominates the land-use. The aim of the Tarland Catchment Initiative (TCI) is to advise and implement an objective strategy for the sustainable use of the catchment and to improve the quality of the catchment's water resources, their adjacent banks and the habitats that they can support. The initial focus of the TCI is to reduce the impact of high concentrations of suspended soil sediments and coliform bacteria in the selected streams and to improve the diversity of the catchments habitats. Continuous monitoring of water quality at the lower end of the catchment has been in place since 1999. This allows for the examination of the variation in water quality between years, seasons and over individual storms. In addition spatial surveys of water quality across the tributaries of the catchment are being undertaken. The water quality parameters measured are pH, conductivity, suspended solids, nitrogen, phosphorus and bacterial coliforms. 1.3 The importance of land management for water quality There are several recent Government documents that have reviewed the water quality status of water in England (e.g. Defra 2002a; Defra 2004). It is generally accepted that agriculture is the largest contributor to many of the water quality problems. For example, agriculture contributes an estimated 70% of the total input of N to surface waters (The Royal Society, 1983) whereas other reports have shown the importance of land use as factor influencing P

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export (McGuckin et al., 1999; Meeuwig et al., 2000). Similarly, agriculture is the largest user of pesticides, and represents an important source to watercourses and groundwater. For example, the herbicide isoproturon has been the most frequently detected substance in freshwaters for many years, and is used exclusively on arable crops, i.e. not the non-agricultural sector. There are approximately 175,000 holdings farming 18,549,000 ha in the UK, (75% of the land area of England and Wales) (Defra 2001). By necessity, agriculture uses many inputs, such as organic and inorganic fertiliser, pesticides (herbicides, fungicides and insecticides) and veterinary medicines. There are also soil and animal management practices that may increase the risk of polluting watercourses or groundwater. While the type and amount of these inputs will vary between farm type, and whether the farm is run under organic principles, there is an ever-present risk from any system. Since the inception of the project in 2002, there has been continued attention on rural diffuse pollution and diffuse pollution from agriculture (DWPA). The changes under CAP reform, Cross Compliance and new Environmental Stewardship Schemes will have impacts on farm management and on emissions from agriculture, but there is considerable uncertainty as to the scale of improvement of water quality (Silcock et al., 2004). It will be important to monitor the effect these changes have on water quality. It is also desirable to investigate what effect Entry Level Stewardship can have on water quality in a known catchment and Whittle Dene is an excellent catchment to conduct these investigations. This is discussed further in Section 5. The importance of the rural landscape on water quality has therefore become an important area of research in an effort to meet targets under the WFD. In particular, the interaction of land management with water quality is understudied at the catchment scale. This has created the need to screen large areas for risk of impact on the water environment so that resources can be focussed by substance, by area or by sector. Small catchments represent a very valuable research tool since they potentially contain sufficient complexity to allow extrapolation to larger areas, but care should be taken on their selection to ensure that they are indeed representative of a larger area. For research purposes, catchments such as Whittle Dene will add to a relatively small knowledge base on water quality interactions with land management. Monitoring a relatively small area allows detailed investigations to be conducted on specific processes that impact on water quality. The generic processes involved will be applicable to a much wider area so care needs to be taken that the general methodologies are appropriate. The work at Whittle Dene has included detailed catchment characterisation of a key area that impacted on water quality. The following sections will describe how the various activities that contributed to the characterisation were conducted. The results of the individual studies will then be presented, before discussing the interactions between them and how water quality issues were related to catchment characteristics, farm and land management. Finally, the methods and policy instruments now available for implementation will be described.

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2. METHODS 2.1 Project management A Project Steering Group was established and regular meetings were convened. Membership of the Steering Group comprised representatives of the project funders and main stakeholders, together with invited experts on occasions. There were several changes in individuals and the current Steering Group is detailed in Appendix 1. 2.2 Establishing catchment studies – practical considerations Despite widespread interest in their use, there are currently no guidelines for establishing pilot monitoring studies. It is appropriate at this point to describe some of the generic approaches that should ideally be followed, before describing the instrumentation at Whittle Dene. The level of catchment scale monitoring of diffuse pollution is dependent on available resources. Ideally, sampling should be conducted in conjunction with flow monitoring in order to calculate loadings of determinands in addition to concentrations. The sampling regime also needs to be responsive to changes in discharge or rainfall, since diffuse pollution is often transport limited (though source areas can also be a limiting factor). In practice diffuse pollution monitoring over large areas at sufficient spatial and temporal resolution, and potentially for a range of diverse determinands (e.g. NO3, TP, MRP, SRP, pesticide(s), sediment, FIO’s), is resource intensive and is not a practical proposition. There is a general consensus in catchment research that small representative catchments (sometimes called ‘microcatchments’) are highly useful. Microcatchments are usually between 1 and 10 km2 and are selected to incorporate the key features and characteristics of the landscape and wider catchment in question. Such features or characteristics would include landuse, landcover, soil type, drainage, topography, crop type and farm type. Usually, the general areas for consideration will have been initially selected from desk-based studies and from modelling exercises. There may also be some water quality data that can be used to highlight potential areas that might be suitable, subject to site visits. The next stage, after identifying suitable areas or candidate microcatchments, is to conduct site visits to assess their suitability. A pre-requisite at this point is the co-operation of all landowners, tenants and individuals involved. It is also necessary to identify wider stakeholders, such as the local council, highways, angling groups, and all other significant land users who will have land in the small area concerned to explain what is required and to request permission to access land and conduct investigations. In practice, a ‘lead in’ will help and these should be explored in the first instance before contacting the groups concerned; for example landowners and farmers may already know and trust a local agricultural consultant. All potential sampling sites within a microcatchment should be visited to assess their suitability and to take appropriate measurements (e.g. channel depth, width, bed composition). In the case of headwater catchments dominated by drainflow, the drain outfalls should be given particular attention since these could be in a poor condition and might be impossible to instrument (e.g. blocked outfall pipes; silted drainage ditch; poor, or non existent, outfall head into the drainage ditch from an outfall pipe). However, it is possible that the poor condition of drain outfalls and drainage ditches reflects the general condition of the underdrainage schemes within the area. In this case, it is more important to devise a monitoring scheme that reflects the wider area, since poor drainage might be a cause of increased runoff and diffuse pollution; a pragmatic view should therefore be taken to devise a compromise monitoring solution wherever possible.

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When investigating potential sites, it is usually important to make reconnaissance visits in the autumn and winter when the drains are running. This will avoid choosing drainage outfalls that do not run, despite appearing in good condition during the summer months. Additionally, the discharge of the general watercourses can be assessed and a more complete understanding of the hydrology is achieved. A further advantage of conducting site visits to small headwater streams in the winter is that bankside vegetation will be less dense than during the summer. It can be very difficult to identify features such as drain outfalls in the summer when they are usually not flowing and may be nearly obscured by soil and vegetation in the bottom of a ditch, but in the winter they can often be heard running and are easier to identify. For higher order channels with year-round flow, this aspect is less important. If the site is to be designed to monitor flow (discharge), the proposed sampling point needs to be able to accept hydrological equipment and installations. This requires a channel that is relatively straight and unobstructed. In addition, the site should be accessible to installation equipment (e.g. mechanical excavators) and this access needs to be maintained throughout the project to allow sample collection and equipment maintenance. This may not always be straightforward. Growing crops may bar the way for the majority of the year and there is a risk of trafficking grassland in wet conditions. Finally, and most importantly, the landowner and/or tenant needs to be fully informed and agreeable. Before any installation work in watercourses can take place, the local EA drainage officer must be informed. Depending on the nature of the work, a formal application will usually have to be made to the EA and sufficient time should be allowed for a response before work commences. Based on the results from the desk exercise, in theory, the procedure to select research catchments and then devise a suitable monitoring programme should be relatively straightforward. In practice, the overlap between suitable candidate areas, stream type, physical characteristics, co-operative landowners (often several neighbouring farms) and sites suitable for instrumentation, can be very difficult to achieve. Very often the surface and subsurface hydrology can be more complicated than initial appearances suggest. Accurate drainage plans for fields can be lost, or unavailable, if they exist at all. Additionally, there can be historical drainage schemes, long forgotten, but sometimes still wholly or partly functional, which add a complicating element that is very difficult to quantify. 2.3 Whittle Dene Western Catchment Characterisation At Whittle Dene, there was a good general understanding about the catchment and its environs following a scoping study (Hillman et al., 2002). Unfortunately, the scoping study was conducted as Foot and Mouth Disease (FMD) was confirmed and this prevented access to the catchment due to disease precaution restrictions. Similarly, it was also not acceptable to contact the farmers concerned at this time. Thus, the scoping study exercise was largely desk-based, with limited site visits when access restrictions allowed. A local consultant was appointed as catchment liaison manager. The consultant concerned was experienced and trusted by the farmers in the area. The various staff employed on the project were all instructed to pass all communication to the farmers via the catchment liaison manager although, later in the project, this instruction was relaxed as the farmers became familiar with the research team. This co-ordinated approach avoided confusion and multiple requests being passed to the farmers concerned. For example, over the course of the project there were staff engaged on hydrological assessments, water monitoring, soil sampling, soil assessments, aquatic ecology surveys, aquatic vegetation assessments and collection of farm information.

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2.4 Water quantity The Whittle Dene Western Catchment was delineated by interpretation from published maps and fieldwalking. Several technical staff who were locally based with Northumbrian Water Ltd were consulted on points of detail. Additional local knowledge was sought on drainage and field underdrainage from drainage contractors and the farmers concerned. 2.5 Water monitoring strategy Several field visits were undertaken to devise a suitable water monitoring strategy. Figures 2.1 and 2.2 show the WDWC and sampling locations. At each of the gauging structures (marked ‘F’ in Figure 2.2) a set of instruments similar to that in Plate 2.1 were installed. These flumes were located in the main Whittle Burn (F1 and F2) and in the watercourse draining land from the north of the catchment (F3). The flumes were located at sites that were deemed suitable for installation; allowed regular access; and were useful from a hydrological/water quality viewpoint. Table 2.1 provides details of the sample locations.

Figure 2.1 Map of the WDWC and surrounding area (inside red line)

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G2

G4

F2

F3

G5

G6

D2D3

Key

F: Flume and sampler

D: Field drain monitoring point

G: Grab sampling location

: Burn or ditch

F1 G3

Farm 1

Farm 2

Farm 3

Farm 4

Houses

House

Figure 2.2 Aerial image of the WDWC (inside red line)

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Plate 2.1 Water sampling equipment and telemetry The flumes provide an estimate of discharge by means of a stage-height/discharge relationship. The stage height was measured constantly by an ultrasonic probe and this data was stored in a datalogger. At each site, an ISCO 6700 automated water sampler was installed which is triggered to take a water sample by the datalogger when the water level in the burn starts to rise. Subsequent samples are taken at intervals decided by an algorithm in the logger (Armstrong et al., 2000). Data was retrieved daily (Mon-Fri) from ADAS Gleadthorpe, Notts using a GSM modem. Data was reviewed, checked and imported into WISKI hydrological software (Kisters AG, Aachen). Three other sites were also established to monitor water quality from selected drains in the catchment using ISCO 6700 series samplers. In addition to these instrumented sites, several locations were chosen to collect ‘grab’ (sometimes also called ‘spot’ samples). These sites were deemed desirable for monitoring, but were not suitable for automatic water samplers due to technical or resource considerations. The sites are listed and described in Table 2.1.

Table 2.1 Description of the main sampling points in the Whittle Dene catchment.

Sampler ID

Sampler type Details

F1 Flume 800 L sec-1

Structure at the approximate start of year round flow of the Whittle Burn. This site was the earliest opportunity to install any practical gauging structure, and was located immediately downstream of the first block of arable land in the catchment, on a farm boundary. (NZ 041 674)

F2 Gauging structure 1300 L sec-1

Gauging structure on the Whittle Burn approximately 1.5 km downstream from F1. The land use between these monitoring points was mixed grassland and arable. (NZ 057 676)

F3 Flume 1000 L sec-1

Structure in an open ditch that forms a tributary of the Whittle Burn. This channel drains a large block of arable and grassland, as well as taking drainage from a mixed farm holding (NZ 057 677).

D1 Drain Monitoring point in a ‘cundy’ drain outfall. This drain takes drainage from arable and grass fields (NZ 041 674)

D2 and D3 Drain Located at the same point (NZ 060 677). Monitoring point from an open ditch that takes drainage water from a large arable field with a ‘headwater’ area of a wet depression in a grazed grass field. D3 is a historical stone cundy drain which runs through an arable field.

G2 Grab sampling point

Site of ephemeral flow of the Whittle Burn. Immediately downstream of a grazed grass field and block of forestry but is before any arable land.

G3 Grab sampling point

Immediately downstream of F1 and D1, after a road culvert.

G4 Grab sampling point

Open ditch, taking water from several field drains, but primarily from yard runoff from a mixed farm with beef cattle.

G5 Grab sampling point

Sampling point for D2 when flow conditions were too low for automatic sampling

G6 Grab sampling point

Sampling point for D3 when flow conditions were too low for automatic sampling

If samples were triggered, field staff in Newcastle were contacted to collect the sample bottles and replace them. Samples were then either stored under appropriate conditions (<4 0C but not frozen, in dark conditions) for collection and delivery by overnight courier (N, P pesticides, sediment), or delivered by hand to a local laboratory for determination of faecal indicators. A tipping bucket rain gauge was installed adjacent to site F2. The data was collected using Campbell Scientific CR10 data loggers and relayed to ADAS Gleadthorpe via telemetry. A plastic rain gauge was also installed as a “check” gauge for the tipping bucket. 2.6 Water quality 2.6.1 Nitrate and phosphorus analysis Nitrate and phosphorus water samples were analysed using standard methods by Direct Laboratories, Wergs Road, Wolverhampton.

11

Nitrate was quantitatively reduced to nitrite adding copperised hydrazine solution to the sample. The nitrite (reduced nitrate plus original nitrite) was then determined by diazotizing with sulphanilamide followed by coupling with N-(1-naphthyl)ethylenediamine dihydrochloride. The resulting water-soluble dye had a magenta colour which was read at 520 nm on the Aqua 800 Advanced Quantitative Analyser. Three main fractions of phosphorus were determined: soluble molybdate reactive phosphorus (SRP), total dissolved phosphorus (TDP) and total phosphorus (TP). In reality, the differences between SRP and TDP were small, and only SRP is reported in this document. Soluble Molybdate Reactive Phosphorus (SRP) was determined after filtration through a 0.45 µm filter. This was measured by an Aqua 800 Advanced Quantitative Analyser. Total Dissolved Phosphorus (TDP) was determined after filtration through a 0.45µm filter. This was measured by the Aqua 800 Advanced Quantitative Analyser (PColW) after conversion to molybdate reactive phosphorus by hydrolysis with di-Potassium peroxodisulphate (potassium persulphate) Total Phosphorus (TP) was determined on the unfiltered sample. This was measured by the Aqua 800 Advanced Quantitative Analyser (PColWU) after conversion to molybdate reactive phosphorus by hydrolysis with di-Potassium peroxodisulphate (potassium persulphate) 2.6.2 Sediment analysis Suspended solids were removed by from a measured volume of sample by filtration under reduced pressure through a pre-treated, pre-weighed, glass fibre filter paper and determined gravimetrically after washing and drying at 105° ± 2°C. Analysis was conducted by Direct Laboratories Wergs Road, Wolverhampton. 2.6.3 Pesticide analyses The analyses of pesticides in water were conducted by by Direct Laboratories, Wergs Road, Wolverhampton. The analysis of isoproturon was performed by reverse phase HPLC after extraction using dichloromethane. The analysis of carbofuran, propyzamide, chlorpyrifos and cypermethrin was performed by GC-MS after extraction using dichloromethane 2.6.4 Faecal indicators and pathogens The analyses of FIO’s and pathogens were conducted by AES Horsley, Newcastle upon Tyne. The isolation and enumeration of Enterococci, Faecal Coliforms and Escherichia coli in water samples was achieved using Membrane filtration and culture on selective media based on methods outlined by EA (2002). The isolation and enumeration of Cryptosporidium oocysts from water was achieved using Genera Filta-max ™ and based on methods detailed by DWI (2000).

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2.7 Pesticides selection for the monitoring project Five pesticides (Table 2.2) were selected for analysis, reflecting a range of uses and physical-chemical characteristics. The pesticides reflected substances that had previously been detected in watercourses and reservoirs at Whittle Dene (Section 3.3). The tendency for a pesticide to move with water through soils is partly determined by its chemistry. This is referred to as ‘leaching potential’. Hornsby's index for pesticide leaching potential is a combination of the organic carbon adsorption coefficient (Koc) and its half life (T1/2) (Hornsby, 1992). The ratio of Koc and T1/2 is multiplied by 10 to give a leaching index for each pesticide. A pesticide with a Hornsby index of 10 or less or Koc of 100 or less would have a high leaching potential. If the index is 2000 or greater, the pesticide would have a low leaching potential. Pesticides that do not meet these criteria are considered to have intermediate leaching potential. The Hornsby index is therefore a relative indication of a pesticide’s ability to leach, but other important factors include organic matter content in the soil or application rate, for example. From the characteristics in Table 2.2 it can be seen that cypermethrin has a very low leaching potential and will be adsorbed to organic matter and sediment. Cypermethrin will therefore tend to be mobilised during large storm events, and its movement may be analogous to sediment bound phosphorus. Carbofuran, IPU and propyzamide are all relatively mobile and will tend to be leached from soil. Table 2.2 Selected pesticide characteristics

Name Koc T1/2 soil (day)

Hornsby Index

Details

Carbofuran 44 42 10.5 Carbamate insecticide. Approval for this substance expired as planned on 31 December 2001.

Chlorpyrifos 2827 60 471.2 Contact and ingested organophosphorus insecticide commonly used on cereal crops.

Cypermethrin 19433 30 6477.7 Pyrethroid insecticide commonly used on cereal crops.

Isoproturon 140 29 48.3 Residual urea herbicide for use in cereals Propyzamide 312 60 52.0 Residual amide herbicide for use in a wide range

of crops, most commonly annual dicotyledons in OSR and woodland.

2.8 Application of models for catchment characterisation Models are frequently used to aid the catchment management process and there are several potential uses at each stage. Models can be used as a screening tool in order to identify ‘high risk’ areas; they can be used to identify potential ‘hot spots’ in high risk areas; mitigation options and scenario tests can then be run to analyse the effects of any proposals introduced as part of a catchment plan. In research projects, models are frequently used to identify areas for more intensive study. This enables limited resources to be directed at a specific area. At Whittle Dene, the water quality issues were already established (Hillman et al., 2001) but the source and magnitude of the parameters in question were not understood, prompting this detailed research project. It was, however, desirable to investigate how representative this small catchment is in relation to a wider area of approximately 500 km2. Several models and data sources were used to accomplish this.

13

2.8.1 Pesticides The risk of pesticide loss to watercourses is a national problem. It was likely that large areas of land surrounding the WDWC were at risk where land use and soil conditions were similar to that at Whittle Dene. Modelling is a useful tool to screen large areas of land for risk of diffuse pollution and in this case such an exercise would also indicate the potential scale of the problem in the Whittle Dene area. This is considered to be especially important when working on a relatively small catchment such as the WDWC since any atypical characteristics would make the catchment less representative, and therefore make the study less relevant. The SWAT model (Brown et al., 1996) was used to assess the likely risk of IPU leaching from arable soils in the Whittle Dene area after a typical autumn application of 1.5 kg a.s. ha-

1. SWAT is a semi-empirical model based upon a direct hydological link between soil type and rainfall, pesticide characteristics and attenuating factors. Approximately 500 km2 was modelled. 2.8.2 Nitrate modelling In common with IPU, it was important to relate the losses of nitrate from the WDWC to losses in the wider area (c. 500 km2). The NEAP-N model linked to the MAGPIE GIS was used to estimate the loadings of nitrate in the Whittle Dene area. The national NEAP-N nitrate leaching model is part of the MAGPIE nitrate leaching decision support system (Lord and Anthony, 2000) used to develop government policy on the control of nitrate leaching. A detailed description of NEAP-N is given in various sources (Anthony et al., 1996; Lord & Anthony, 2000; Silgram et al., 2001). In summary, NEAP-N considers a single maximum potential nitrogen loss factor for individual crop and livestock types, which is modified by spatially distributed information on soil type and hydrologically effective rainfall. The MAGPIE system collates the national agricultural and environmental data sets in a GIS framework for input to the NEAP-N model, display and analyses of the results. 2.8.3 Sediment The risk of soil erosion in the wider area (c. 500 km2) around Whittle Dene was modelled. The emphasis was on the identification of ‘high risk’ areas. The robust Morgan-Morgan-Finney model (Morgan, 2001), was used as a rapid, first approximation determination of areas where soil erosion was likely to be relatively large in an ‘average’ year. 2.9 Soil assessment The dominant soil series in 1 km2 squares were displayed for an area of c. 300 km2 surrounding WDWC using existing NSRI datasets. This was important to make sure that the soil types within the WDWC were representative of a wider area. A joint exercise to produce a detailed map of soil series and investigate soil physical characteristics was conducted. Soils within the WDWC were assessed for the characteristics that might affect land-use, drainage, and hydrological flow paths. The fieldwork was conducted during 4 and 5 December 2003, after the soils had wetted up after a very dry autumn. Soils were assessed using a spade and auger to examine soil characteristics to a maximum depth of one metre. Approximately one profile was examined per field, but more were excavated where topographical or other features suggested a change in soil type or characteristics. Soils in fields of the Western Catchment were sampled and analysed for N, P, K, Mg, pH using standard methods for fertiliser requirements. Soils were sampled in 30 cm increments to 90 cm in October 2002, December 2003 and October 2004 for determination of soil mineral nitrogen (SMN) as an indication of leaching potential. The aim was to sample at the

14

start of return to field capacity (FC) and therefore the exact date of sampling was dependant on soil and field conditions. The very dry autumn of 2003 thus prevented sampling until late in the year. Topsoil (0 – 15 cm) from fields in the Western Catchment were sampled for P, K, Mg, pH in February 2003. 2.10 Historical Water Quality Data Environment Agency routine monthly water quality data were extracted from their database as far back as electronic records allowed, from several sampling points in the environs around Whittle Dene (Figure 2.3). The routine EA samples are not flow based, and are primarily collected to support monitoring of point-source emissions to water. Thus, storm events, which drive most diffuse pollutant transport mechanisms, are not specifically sampled, and the concentrations reported will usually be a gross underestimate of diffuse pollution. It should also be noted that analytical and reporting methods are likely to change through time, and that sampling locations may change, but despite these limitations, they are useful to determine trends. The data were collated, and the most useful data based on time series and location were selected.

Figure 2.3 Environment Agency Sampling Points in the Whittle Dene Area

15

Water quality data was also kindly supplied by Northumbrian Water Ltd. This data pertained largely to pesticides, and was usually for reservoirs. This information gives a guide to the likely severity of diffuse pollution, but usually gave no information on the concentrations in feeder streams since the water supply to the reservoir system is complicated (see Section 3.1). Additionally, it should be noted that the Whittle Burn was diverted around the reservoir system in 2001 to prevent pesticide contamination since the Western catchment was considered to be at ‘high risk’ from pesticides. However, with these caveats in mind, the concentrations of pesticides in the reservoirs provide a guide to the severity of pesticide losses in the general area around Whittle Dene since several watercourses are used to fill the reservoirs. 2.11 Farm & field survey A Senior ADAS consultant was tasked with collecting information on farm holding characteristics and field management/cropping practices. A proforma was used to collect information (Appendix 3). However, it was soon apparent that access to farm records and data for fields was problematical. All available information was collected, but more detailed information (e.g. animal movements around fields used by one holding) was usually less complete. Nevertheless, the data was used appropriately in conjunction with the water quality and soil monitoring programme (Section 3). 2.12 Aquatic survey Whittle Dene Reservoir Complex is listed as a Site of Nature Conservation Importance (SNCI) for value as a wintering site for wildfowl. There are freshwater habitats, coniferous plantations, neutral grassland and marshy grassland. The marshy vegetation on the margins of the Western Sub Reservoir is the most extensive within the complex. A high diversity of swamp and marginal aquatic plant species makes the site potentially valuable for aquatic invertebrates and birds. Invertebrate groups are good indicators of water quality (e.g. Chapman and Jackson, 1996). A survey of aquatic invertebrates, for species of conservation concern therefore provides a practical means of determining water quality and habitat condition. Samples can be examined in the laboratory and identified to species, family or order, with particular attention being given to indicator species. Groups of particular interest include freshwater shrimps (Gammarus pulex), caddis-flies (Trichoptera), stoneflies (Plecoptera), mayflies (Ephemeroptera) and dragonflies (Odonata). A relatively small-scale survey, focused primarily on aquatic and riparian flora and aquatic macro-invertebrates within the study area, was undertaken to provide an indication of the present ecological value and a baseline for possible future research and monitoring. Sample sites along the Whittle Burn, between Shildonhill plantation and the western edge of the reservoir were surveyed for macro-invertebrates. Taxa identity and abundance, taxa richness, and BMWP scores were calculated for each site sampled to provide a measure of diversity in the stream. Samples for macro-invertebrates were collected from seven sites along the Whittle Burn in May and September 2003 to ensure that taxa were not missed early or later in the Summer, depending on species life-histories. Ten replicates were taken at each point. A second sampling visit was conducted on 15 September. However, weather conditions throughout the summer of 2003 resulted in atypically dry conditions and much of the stream was too dry to sample. Therefore, samples were collected using a procedure that deviated from the standard sampling method.

16

Each sample included different habitat types (open water, under bank vegetation, different substrate types) proportional to their cover. The kick/sweep surveys were supplemented by either sweeping surface waters in static water or inspecting benthic substrate by hand in flowing water. Net contents were emptied into a bucket and rinsed by sieving out macro-invertebrates and large debris, with a 2 mm sieve. The sieve contents were put onto a white tray, with some clean water and organisms were then hand-picked and placed in sample jars with preservative. In May 2003, a standard kick-sampling method was used to collect macro-invertebrates. The technique used was adapted from the Manual Sampling technique involving sample collection in three parts:

1. Manual Search – Individual animals collected from the water surface. The time spent collecting for parts 1 and 3 total one minute. 2. Main Sample – Samples were collected by either: i. Shallow/wadeable: 3 minute active pond-net sample collected by a combination of kicking and sweeping, depending on the nature of the substratum, current and habitats, for benthos and free-swimming animals. All habitats sampled in proportion to their cover. ii. Deep waters/non-wadeable: Too deep to kick sample whole site. Possible to sample at least some of the main channel with a long handled pond-net: 3 minute active pond net sample collected by a combination of kicking and sweeping for benthos and free-swimming animals. Attempts made to sample all habitats in proportion to their cover, although this may not be possible for habitats in the main channel. 3. Manual Search – Individual animals collected from submerged rocks, logs and vegetation.

A hand net was placed, pointing upstream, in the flow of water, ensuring that direction of flow passed through the net. The net aperture was held vertically with the rim firmly set on the stream substratum. Where possible, the area of each kick sample was also consistent (approximately 25 cm by 50 cm and disturbing the substrata to a depth of approximately 15 cm). Kick sampling was timed for one minute per sample to minimise variability in sampling effort between samples. Disturbance of samples was avoided by beginning downstream and working back upstream. This ensured that previous sampling activity did not affect fauna from remaining sampling points at each site. Similarly, sample sites were visited, starting from the downstream site and working back to the upstream site. In September 2003, most of the Whittle Burn did not contain water as a result of the exceptionally dry summer and autumn. Because of these conditions, the recognised method of standard kick-sampling could not be practised and so the following procedure was conducted. Surveyors walked the course of Whittle Burn to identify wet areas. Sampling could not be repeated at the same locations as the sampling sites surveyed in May. Two parts of the course, both consisting of several pools or puddles, were identified where there was sufficient water to sustain aquatic life. At each of sampling site, along the course, five replicate samples were collected.

17

As there was no current, kick-sampling was substituted for sweeping and dragging the hand net through the pool, ensuring that all habitat types were included in each sample (i.e. under overhanging vegetation, amongst aquatic vegetation and through open water). The technique was not timed as each pool varied in size. The whole volume of water was, as far as possible, sampled by dredging the net through the pool. Once sampled by netting, manual collection of animals attached to substrata or surface dwelling was undertaken as in the manual searches done in May. 2.12.1 Identification and enumeration of samples All samples collected were put into 500 ml sample jars, preserved in 70% ethanol and returned to ADAS Boxworth for identification and enumeration. Samples were sorted and identified using a binocular, low-power microscope under laboratory conditions. Preserved samples were stored in the cold store room (4 ± 2°C). 2.13 Vegetation assessment A vegetation assessment was carried out on 09/07/03 and 14/07/03. The catchment was divided into a number of sections depending on either the vegetation or on field boundaries. The species were categorised with some supporting habitat information before being allocated Ellenberg Indices for F (Moisture) and N (Nitrogen) in order to provide supporting information on flow regimes and the trophic state of the Whittle Burn. 2.14 Mobilisation and delivery of N and P The source, mobilisation, delivery and impact of several determinands were investigated at Whittle Dene. However, it was important to study and measure the mobilisation and impact in more detail from selected locations. A funded PhD study was instigated to investigate this aspect. The main objectives of this on-going project are:

• to investigate the behaviour of nitrate and phosphorus during storm events • to determine dominant hydrological flow paths of nitrate and phosphorus at the field scale during storms, and link them to pollutant mobilisation and delivery • to produce recommendations on runoff management plans from selected locations

Field ‘S9’ was chosen to be studied in detail as it was easily accessible, was considered to be representative of arable farming practice in the sub-catchment and there was visual evidence of overland flow. Field S9 was also adjacent to water sampling site ‘F1’. Six peizometers were installed to sample soil water during storm events for subsequent determination of nitrate and phosphorus. Three soil cores of 1 m and 2 m depth were taken using an Archway Engineering competitor 1.30 Soil Sampler. The samples were labelled and stored for analysis. The bored holes were lined with 32 mm diameter PVC tubing. At the bottom of each tube, approximately sixty holes of 0.5 cm diameter were drilled to allow water to enter from the bottom. The outside of the tubing near to the surface was sealed with Mikolit 300 bentonite pellets to ensure that water could not enter the soil profile through this route. A van Essen, diver datalogger (model DI240) was installed in each piezometer to record water levels. The piezometers were positioned in one-metre and two-metre deep pairs at three locations across field S9, parallel to the Whittle Burn. Each piezometer was approximately one metre from the burn and placed approximately 0.5 m apart.

18

Overland flow was considered to be significant in field ‘S9’. Visually, the field clearly showed surface water flow-paths towards the burn. An exercise was conducted to investigate the importance of surface flow paths on P transport within this field. First, the field was digitally mapped using GPS equipment. Next, a digital elevation map was created in ARC GIS and transformed into a flow accumulation map via GIS and terrain analysis software. The exact location of each GPS sampling point was taken using GPS, allowing repeated sampling of soil at exactly the same location. Soil cores were taken from selected locations in Field S9 using a mandelson auger to a depth of 15cm (arable field) and analysed for P (See Section 2.12). Areas of large and small flow accumulation were selected to investigate if there were any differences in the concentration of P. Diver data, showed that subsurface water movement in each piezometer was very similar and that they were all responding in the same manner. Two pairs were subsequently removed.

19

3. RESULTS 3.1 Physical description The Whittle Dene Reservoir Complex consists of 5 interconnected reservoirs at GR NZ 065683, approximately 18km west of Newcastle upon Tyne. The reservoir complex consists of the Great Northern, Northern, Western, Lower and Great Southern Reservoirs, as illustrated schematically in Figure 3.1. The Whittle Dene Reservoirs represent the lowest in a complex which includes the larger upland impounding reservoirs of Catcleugh (NY 7403), Colt Crag (NY 9378), and Hallington Reservoirs (NY 7697). Originally built to supply hydraulic power to cranes at the Armstrong Shipyard on Tyneside, the Whittle Dene Reservoirs were constructed in the period 1848 to 1857. They were soon put to alternative use to supply mains water to the conurbation of Newcastle and are now central to the water supply for Newcastle and surrounding areas. They currently supply drinking water to approximately 600,000 consumers. The total direct catchment area to these reservoirs is approximately 32 km2. The many tributaries, burns, rivers and man-made aqueducts in the system form a complicated, but flexible, network with which to manage water in the reservoir system (e.g. Plates 3.1 and 3.2). However, the Victorian engineers had no need to consider diffuse pollution and even less so since the water was originally intended as power, not a potable source. The catchment areas of the major reservoirs have been assessed by Northumbrian Water Ltd for risk from diffuse pollution (Figure 3.1). The large upland reservoirs (Catcleugh – Hallington) are considered to be relatively low risk. The land between the Hallington Reservoirs and the Whittle Dene Reservoir Complex is border uplands, and primarily consists of mixed agriculture. Thus, the Whittle Dene ‘Catchment’ is considered to be at relatively high risk of contamination subject to local characteristics and conditions, adverse farm management, or accidents.

Plate 3.1 Aqueduct at Whittle Dene

20

Great SouthernCapacity-233.2Mg

NorthernSub

NorthernCapacity-30.7Mg

Northern ReservoirsCatcleughColt Crag

Little SwinburnEast HallingtonWest Hallington

Total Capacity-4,832Mg

Great NorthernCapacity-104.4Mg

LowerCapacity-98.5Mg

WesternCapacity-62.1Mg

DirectCatchment(High risk)

DirectCatchment(High risk)

Direct Catchment(Low risk)

Whittle DeneWTW

HendersonWTW

HorsleyWTWTyne at

Ovingham

DirectCatchment(High risk)

DirectCatchment(High risk)

= Water abstraction points Figure 3.1 Schematic diagram of the reservoir network (Source: NWL)

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Plate 3.2 Whittle Burn entering the reservoir complex The area of the Whittle Dene Project is the small ‘Western catchment’ (WDWC) (c. 3.9 km2) which has historically fed the Western Reservoir. The WDWC was hydrologically isolated from the reservoir complex in 2001, primarily because water quality had deteriorated and alternative methods of filling the Western Reservoir were available. The Western catchment slopes gently down towards the North East, with the highest point at 189 metres in the South Western corner at Shildon Hill. It falls in moderate slopes to 130-140 metres at the Bywell Road and then more gently towards the Whittle Dene reservoirs, which lie at 117 metres AOD. The main stream which feeds the reservoirs rises in the upper slopes on the Western edge of the site and flows eastwards. Other minor streams arise from springs south of the B6318 and east of Vallum Farm. A combination of analysis of published maps and fieldwalking revealed that the WDWC was generally well delineated. The road network tended to follow the interfluves and, compared to many small catchments, the drainage in and out of the catchment area was relatively straightforward. However, there were fields outside the road ‘boundary’ at Kip Hill (NW) that were also likely to drain into the catchment, although the drainage plans did not exist and the exact drainage was difficult to identify. There is a small spring and a drain in the east of the small WDWC and these are thought to originate from Kip Hill. A crude water balance was conducted for the month of November 2004 to account for rainfall across the WDWC compared to flow out of the catchment. This exercise did not account for alternative water losses from the catchment, such as evapotranspiration (Et) from crops, but winter values for Et in the UK are low compared to summer months, typically <20 mm/month (Shawyer and Westcott, 1987). Areal measurements of rainfall are also notoriously difficult

22

and it is possible that the rainfall across the catchment varied compared to measurements at the single automatic raingauge at GR NZ 057 676. With these factors in mind, the total rainfall across the monitored area of the catchment was estimated as 88,884 m3 in November 2004, compared to a measured surface runoff value of 98,024 m3, an error of approximately +10%. 3.2 Concentrations of nitrate in recent years Historical water quality data from the EA were available from several locations for nitrate, starting in the late 1970’s and 1980’s, as described in Section 2.10. The most useful data in terms of time series and sampling location are shown in Figures 3.2 to 3.4. As noted in Section 2.10, these results were obtained by spot sampling and were not flow-related. Depending on the physical-chemical characteristics of the pollutant in question, the concentrations will often be larger during rainfall events, which can be responsible for large proportions of the total diffuse pollution load. Conversely, where pollutant transport is source limited, high flow can dilute concentrations, even though the loads of the pollutant in question can be large.

0

5

10

15

20

25

03/90 03/92 03/94 03/96 03/98 03/00 03/02 03/04

nitr

ate

N (m

g/l)

FMD

Wet autumn2000

Figure 3.2 Concentrations of nitrate-N in the Whittle Burn at Ovingham

23

0

2

4

6

8

10

12

14

16

10/89 10/91 10/93 10/95 10/97 10/99 10/01 10/03

Figure 3.3 Concentrations of nitrate-N in Coldicoate Burn, Ponteland

0

2

4

6

8

10

12

14

10-Jan-78 04-May-83 25-Aug-88 17-Dec-93 10-Apr-99 01-Aug-04

Nitr

ate-

N (m

g/l)

Figure 3.4 Concentrations of nitrate-N in the River Pont at Kirkley Mill The charts in Figures 3.2 to 3.4 show concentrations for three different streams in the area, the Whittle Burn, Coldcoates Burn and the River Pont and all display the same pattern during this time. A common feature of the data were peaks in concentrations in the autumn and this is a result of nitrate being leached from the soil after harvest during the autumn and winter rain. The magnitude of the peaks in autumn nitrate was relatively small in 2000 - 2002.

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The concentrations of nitrate in spot samples from the Whittle Burn exceeded the 11.3 mg NO3-N L-1 limit routinely in autumn and winter in the 1990’s, while the concentrations of nitrate were also large in the River Pont and Coldcoates Burn. 3.3 Concentrations of pesticides in recent years The concentrations of pesticides in the reservoir system in recent years were reviewed by Hillman et al. (2002). The magnitude and frequency of pesticide concentrations (>0.1µg L-1) in raw (untreated) water from the Whittle Dene complex has increased since the mid 1990’s (pers comm NWL). Several pesticides have been found at concentrations exceeding the 0.1µg L-1 standard for individual pesticides in water, and, in common with other UK watercourses, Isoproturon (IPU) is a particular problem. IPU is a residual urea herbicide for use in cereals against annual grasses, blackgrass, wild oats, rough meadow grass, and annual dicotyledons and is applied in autumn or spring to cereals. Hillman et al. (2002) reviewed data for 21 April, 11 and 20 May 1999, showing concentrations of IPU at various points along drains and burns that flow into the reservoirs. The highest concentration (9.6µg IPU L-1) was observed entering the reservoir complex. All samples taken on 21 April and 11 May contained IPU at concentrations above the 0.1µg L-1 limit. In autumn 2000, there were no seasonal increases in IPU concentrations as a result of spraying. Instead there was a peak concentration of 3.7 µg L-1 in March 2001. This period was characterised by an extremely wet autumn and spring across the country, which restricted field operations significantly (Shepherd, 2004). Thus, the wet autumn indirectly reduced the chance of losses of IPU and other pesticides since there were few opportunities for applications to be made. In contrast, many farmers and spray contractors took the opportunity to make targeted applications of pesticides during the first dry window of weather in spring 2001. Unfortunately, spring 2001 was also wetter than average, and there were significant losses of IPU, resulting in the large concentrations observed in water during March. Data supplied by NWL for the years 2000 – 02 showed that many pesticide substances were present in watercourses in the area around Whittle Dene, to the extent that the reservoirs contained total pesticides >0.5 µg L-1 and individual pesticides >0.1 µg L-1 during the main spraying seasons. This implies that the watercourses feeding the reservoirs contained pesticides in excess of those found in the reservoirs. It should be emphasised that this is ‘raw water’; i.e. before treatment at a water treatment works to remove contaminants such as pesticides and purify the water, before subsequent mains distribution. In common with other catchments nationwide, the herbicide isoproturon (IPU) has been detected at high concentrations sufficient to cause operational problems at the respective water treatment works. In particular, during autumn 2001, concentrations of 14.0 µg IPU L-1 were detected in the Whittle Burn. Concentrations of this magnitude are likely to have been repeated in many of the local watercourses in order to have caused concentrations of 7.0 µg IPU L-1 in the Great Southern Reservoir, for example. Both the frequency and magnitude of pesticide exceedences (>0.5 µg L-1 total pesticides or >0.1 µg L-1 of an individual substance) have increased since the early 1990s (NWL, pers comm). Several substances were detected in the reservoirs at Whittle Dene between 2000 and 2002, and the most common ones are listed below: • 2,4-D: translocated phenoxy herbicide for cereals, grass and amenity use • Carbofuran: carbamate insecticide for soil treatment, likely to be used on OSR at Whittle

Dene

25

• Chortoluron: contact and residual urea herbicide for cereals • Diuron: residual urea herbicide for non-agricultural use • Isoproturon: a residual urea herbicide for use in cereals • MCPA: translocated phenoxyacetic herbicide for cereals and grassland • Mecoprop-P: translocated phenoxypropionic herbicide for cereals and grassland • Propyzamide: residual amide herbicide for a wide range of crops (likely to be used on

OSR at Whittle Dene). The extent of the general problem of pesticides in feeder streams to the Whittle Dene Reservoirs is illustrated in Figure 3.5, which shows the concentration of IPU in the five-reservoir Whittle Dene complex in 2002. The spring spraying season for IPU coincides with high concentrations in the reservoir system with concentrations generally between 0.2 and 0.3 µg IPU L-1 in the reservoirs. The Lower Reservoir had concentrations of IPU up to 0.8 µg L-1, but the reasons for this are unclear at this time.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

05/03/2002 14/04/2002 24/05/2002 03/07/2002 12/08/2002 21/09/2002 31/10/2002 10/12/2002 19/01/2003

IPU

(ug/

l)

Gt Northern Northern Western Low er Gt Southern

Figure 3.5 Concentrations of IPU in the five reservoirs at Whittle Dene 2002 (Source:

NWL) The magnitude and peaks of IPU concentrations in the reservoir system were variable in autumn 2002. Diffuse runoff from agricultural land tends to be directly related to rainfall events, and it is therefore probable that these concentrations are directly related to rainfall during the autumn spraying season. 3.4 Rainfall and flow 2003 - 2004 The long term average yearly rainfall at Whittle Dene is 670 mm (Smith, 1984). The site is in the rain shadow of the Cheviot Hills to the West, where the uplands of Northumberland have an average rainfall of 939 mm. The total annual rainfall in 2003 was 406 mm, which was 39% below average. Spring, late summer and autumn were very dry compared to the long term average (Table 3.1) and this translated into very low flow conditions in the Whittle Burn, as seen in Figure 3.6. The burn was largely dry from August until November, which was considered to be a very rare event by the local farmers.

26

Table 3.1 Monthly rainfall 2003-04 and long term average rainfall 1941-70 Long term

average 12003 2003 as % of

average 2004 2004 as % of

average Jan 61 25 41 94 155 Feb 49 22 46 33 67 Mar 41 22 53 31 75 Apr 44 20 46 76 173 May 51 52 101 23 45 Jun 48 88 183 82 172 Jul 60 11 19 73 122 Aug 78 15 19 153 196 Sep 59 40 68 22 38 Oct 54 49 91 103 190 Nov 70 25 35 27 38 Dec 55 37 68 37 68 TOTAL 670 406 61 754 113 1 Smith, (1984)

0

50

100

150

200

250

300

350

400

450

500

18/0

1/03

07/0

2/03

27/0

2/03

19/0

3/03

08/0

4/03

28/0

4/03

18/0

5/03

07/0

6/03

27/0

6/03

17/0

7/03

06/0

8/03

26/0

8/03

15/0

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Figure 3.6 Flow (L sec-1) and rainfall (mm) at Whittle Dene 2003 Though crops were harvested in a timely fashion, autumn cultivations across much of the country were badly affected as it was too dry to operate machinery to create a satisfactory seedbed. There were widespread crop establishment failures across much of the country. The dry conditions (and late drilling) resulted in late applications of herbicides, for example. Though there was little rainfall throughout the autumn, it was sufficient to cause the burn to flow, albeit at a very low rate. It was not until rainfall in December that there was significant autumn discharge. Indications are that this flow was largely generated via preferential flow along macropore cracks which remained deep in the soil, below the cultivation layer after the very dry summer and autumn.

27

By contrast, the rainfall during 2004 was much more variable with a total of 754 mm, or 113% of average. A particular feature was the wet summer, which was common over much of the country, culminating in extreme events such as that at Boscastle in the South West of England. Rainfall during June, July and August was 172, 122 and 196% above the average at Whittle Dene, causing corresponding peaks in discharge (Figure 3.7). Whereas the peak flow in 2003 was approximately 400 L sec-1 in December, the peak flow in 2004 was over 1,200 L sec-1 in August. However, both September and November 2004 had less than 30% of the average rainfall. In common with autumn 2003, this translated into low autumn flow, although the near average autumn rainfall in October helped drainage to commence and sustain baseflow during November.

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Rain(mm) F1 Flow(l/s) F2 Flow(l/s) F3 Flow(l/s) Figure 3.7 Flow (L sec-1) and rainfall (mm) at Whittle Dene 2004 Though the project was not specifically designed to examine runoff and water quantity issues, it is important to examine the hydrology in terms of soils and land use. The catchment is dominanted by heavy clay soils with impermeable subsoils. The low infiltration rate of these soils, coupled with relatively inefficient drainage translates into a hydrograph consisting of very pronounced peaks, with a very low baseflow component. This can be seen especially well in Figure 3.7. At a larger scale, catchments such as this may exacerbate short-term flooding. Action can be taken to reduce this risk, which will also reduce diffuse pollution and improve soil management, to the benefit of crop health and yields. The soil characteristics responsible for this are discussed further in Section 4.6 3.5 Water Quality in the Whittle Dene Western catchment 2002 – 2004 The water quality data in the Whittle Dene Western catchment have been presented in two ways. First, the concentrations of determindands (NO3-N, TP, MRP, IPU, propyzamide, faecal coliform and sediment) have been plotted by date and location. This is important in order to place the water quality in context amongst the respective concentrations specified by the relevant legislation. Water quality data have also been flow weighted and totalled by month and year to provide loads of substances.

28

3.5.1 Pesticides IPU was detected in water on the majority of sampling occasions during winter 2003 drainage season, and to the end of July 2003 (Figure 3.8). Peak concentrations coincided with the autumn and spring spraying seasons when concentrations >2.0µg L-1 µg L-1 were found in samples taken from F2 and F3 on 20 March and 23 October, respectively. The EQS for IPU is 20.0 µg L-1, i.e. approximately twenty-times the maximum concentration detected in 2003 to 2004. In January 2005, however, concentrations of IPU reached 10.0 µg L-1 and this will be discussed in the annual report under Phase II.

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Figure 3.8. Concentrations (µg L-1) of IPU at Whittle Dene 2002 – 2004 Spray records show that a mix of diflufenican and IPU was applied to fields S7 and S9 on 17 March 03, and IPU was also applied to a large block of land in the East of the catchment (fields W1, W3, W6, and W10) on 19 March. The peak concentrations of IPU in spring 2003 were detected on 20 March 2003. Rainfall in March 2003, and spring 2003 generally, was approximately 50% below average and just 0.2 mm of rain fell on the day of sampling (time based sample). The reason for the peak concentrations, occurring within a few days of application, is therefore unclear. Similarly, the rainfall for autumn 2003 was also below average (Section 3.4). Soil conditions were very dry and this delayed autumn cultivations and drilling. Just one field (S6) received IPU in the vicinity of sampling point F1 and concentrations remained low at this point. However, concentrations in the drain at D1, which takes water from part of S6, peaked at 1.29 µg L-1 on 21 Dec. Several arable fields across the WDWC received applications of IPU in mid October. Concentrations >0.1 µg IPU L-1 were found in the very low flow which occurred as a result of the late October rainfall following the very dry conditions, thus the applied IPU was readily lost in the first wet conditions following application. It is possible that these losses were largely via macropore cracks in the soil to the drain system. Spray records indicate that no IPU was applied in spring 2004. There was a general trend towards lower concentrations in the watercourses following autumn 2003 and the concentrations that were >0.1 µg L-1 were generally following rainfall (e.g. 19 April). April

29

2004 was 73% above average, and this rainfall may have been responsible for the concentrations observed following applications in late autumn 2003. The concentrations of IPU in spring 2004 were of a similar magnitude to those in autumn 2003. However, the concentrations of IPU in autumn 2004 were very low. The reasons for the low concentrations in autumn 2004 is currently unclear, and the pesticide records for the harvest year 2004 – 05 are due to be collected in Phase II of the project. In 2003, concentrations of IPU remained at, or close to the 0.1 µg L-1 limit until the end of July. However, due to the very low flow in the streams, the loads of IPU were small during the summer (Figure 3.9). Though the concentrations of IPU at Whittle Dene were often > 0.1 µg L-1, these concentrations were low compared to those in recent years, as described in Section 3.3, however, the impact of these concentrations of IPU for prolonged periods at times of low dilution is clearly undesirable. As can be seen, the loads of IPU were dependent on rainfall during the application season with peak loads during March 2003, and winter 2003 – 2004.

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Figure 3.9 Loads of IPU at Whittle Dene 2003-2004 (mg) Propyzamide, a relatively mobile substance, was found in similar concentrations to, but not as frequently as, IPU (Figure 3.10). Larger concentrations have been recorded at the nearby Water Treatment Works (WTW) in years with more rainfall than 2003. The peak concentration of propyzamide was on 6 Jan 2004 at site F1, and it was detected at this site shortly after application to adjoining fields of OSR on 12 December 2003. Similar concentrations were detected shortly after applications to fields adjoining sampling points F2 and F3.

30

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Figure 3.10 Concentrations (µg L-1) of propyzamide at Whittle Dene 2002 – 04 Propyzamide is not commonly reported as being detected in surface waters of England and Wales (EA, 2003), yet it is regularly found at Whittle Dene, usually associated with OSR, though it has also been used to help establish hedgerows in the year prior to monitoring (pers comm). The insecticide cypermethrin was detected at F1, F3, D1, D3 and D3 at concentrations up to 190 ng L-1 in isolated incidents. Detections occurred at F1 and D1 shortly after application in December 2003 and April 2004. The EQS Maximum Allowable Concentration (MAC) for cypermethrin in surface water is 2.0 ng L-1. In addition to use in livestock dips and pour-on products, cypermethrin is often used in arable formulations to control barley yellow dwarf virus vectors and is applied at the same time as some herbicide mixtures. Spray records confirm the application of products containing cypermethrin shortly before it was detected, while the detections occurred out of season for animal use. 3.5.2 Microbial indicators and pathogens The concentrations of faecal coliform (FC) and E.Coli were determined in water samples taken from selected points across the catchment as an indicator of faecal contamination of the watercourses. During the course of the project, additional samples were also submitted for faecal streptococci (FS) in order to calculate the FC:FS ratio. An additional batch of samples were also submitted for determination of Cryptosporidium oocyst concentrations. As seen in Figure 3.11, the data showed a typical seasonal pattern, with concentrations of FC rising from <10 cfu/100 ml in winter 2003, to c. 100,000 cfu/100ml in late summer, falling to <10 cfu/100 ml in winter 2004. This pattern was also observed by Hunter et al. (2001), while Hunter and McDonald (1991) considered that this pattern was related to changes in the long term store of bacteria in the soil, and this in turn was related to changes in factors such as frequency and amount of rainfall, and increased animal grazing in the spring and summer.

31

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FC (

CFU

/100

ml)

F1

F2

F3

G2

G4

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Figure 3.11 Concentration of faecal coliforms at Whittle Dene 2002 – 2004 (log scale)

(CFU/100 ml) Though the pattern of FC concentrations were similar in 2004 compared to 2003, there was an increased spread of concentrations. It is considered that this reflected the increased rainfall in 2004 compared to 2003, which, coupled with a wide monthly variance compared to the average, exhausted FC in the soil at different rates for different fields. Given that some monitoring points received drainage from predominantly arable areas, the fact that concentrations were similar at the major monitoring points indicated that sources were not straightforward. While it was acknowledged that wild animals are a source of faecal material, it was considered that concentrations of the magnitude in Figure 3.11 were primarily from domesticated animals. Cryptosporidium oocysts were determined in samples taken from each gauging structure on 23 June 2004. This sampling followed a period of low flow and coincided with large concentrations of FIO’s in the summer months. The actual sampling was planned to occur during the first significant (c. >7 mm) rainfall and this biased strategy was designed to have the largest probability of detecting Cryptosporidium oocysts mobilised from the soil bank. The peak concentration was found a few meters downstream of the gauging structure at F1, where a count of 471 oocysts per 10 L of water was determined. Concentrations were lower downstream at sites F2 and F3 (20 and 1 oocyst 10 L-1, respectively). The concentrations of Cryptosporidium oocysts at sites F2 and F3 were similar to those reported in the review by Butler and Mayfield (1996), where the range of concentrations in river samples in over twenty UK studies were c. 0.007 to 40.0 oocysts L-1. However, the concentration at site F1 (450 oocysts 10 L-1) was large in relation to those studies reported in the UK. It is important to note that the concentrations reported by Butler and Mayfield (1996) were reported per litre, and not the more common units (oocysts 10 L-1).

32

3.5.3 Nitrate In spring and summer 2003, the majority of water samples from the Whittle Burn contained <5.0 mg NO3-N L-1 (Figure 3.12). The exceptions to this were concentrations in samples taken from D3, which were consistently >5.0 mg NO3-N L-1 over the same period until the small flow from the drain ceased in June. The drain at D3 is strongly suspected as taking domestic drainage (potentially from a septic tank), before running through an arable field to the sampling point. This would explain both its continued flow in very dry conditions from what is essentially just a small arable field, and also larger concentrations of nitrate compared to other sampling locations.

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Figure 3.12 Concentration of nitrate-N (mg L-1) at Whittle Dene 2002 – 2004 The concentrations in the main stream typically remained <5.0 mg NO3-N L-1 until December 2003, and this was due to the very dry autumn, which caused nitrate to remain in the soil profile. It is also possible that the exceptionally dry conditions inhibited mineralisation of organic N, thereby reducing the amount of nitrate in the soil. The advent of the late winter rains caused the concentrations in the main stream to exceed 25 mg NO3-N L-1 as nitrate was leached from the soil in December 2003. There were also peaks up to 34 mg NO3-N L-1 in drain D3. As previously discussed, the monthly rainfall in 2004 was variable, causing a much greater range of concentrations in the catchment. The most significant factor was the above average rainfall from June to August, and, in particular, the heavy rainfall in August was responsible for significant summer losses of nitrate (Figure 3.13). Rainfall in September and November was only 38% of average, resulting in low flow and low concentrations, while the large rainfall in October resulted in significant concentrations and loadings of nitrate.

33

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Figure 3.13 Loads of nitrate-N at Whittle Dene 2003-2004 (kg) 3.5.4 Phosphorus and sediment The concentrations of MRP in the Whittle Burn and feeder ditches exceeded 100 µg L-1 during low flow, and after heavy rainfall (Figure 3.14). The peaks in concentration up to 161 µg MRP L-1at D2 in April 2003 were not flow related, and there is uncertainty as to the cause of these measured concentrations. Similarly, there is also uncertainty regarding the cause of the outliers at site G4. Concentrations tended to increase as flow decreased in summer 2003, and this was probably due to reduced dilution. Concentrations increased in December 2003 after a very dry autumn and peaked at >100 µg L-1 at site F3.

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Figure 3.14 Concentration of MRP at Whittle Dene 2002 – 2004 (µg L-1)

34

In 2004, the peak concentrations occurred in August as a result of the above average summer rainfall. As outlined in Section 3.4, some of these storms were particularly heavy, and were responsible for mobilising significant quantities of TP and sediment (Figures 3.15 and 3.16) with the largest concentrations at gauging station F2, when peak discharge exceed 1200 L sec-1. Similar results were also observed in the rainfall during October.

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Figure 3.15 Concentration of TP at Whittle Dene 2002 – 2004 (µg L-1)

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Figure 3.16 Concentration of suspended sediment at Whittle Dene 2002 – 2004 (mg L-1)

35

The concentrations and loadings (Table 3.2) of MRP in 2003 were less than those reviewed by Haygarth and Jarvis (1999) and Defra (2002) with a range of c. 50-100 g MRP ha-1 yr-1 for typical UK conditions. However, the loadings of MRP were increased by up to a factor of nine in 2004 (at F2) compared to 2003, resulting in concentrations and loadings that were of a similar magnitude, (e.g. 86 g MRP ha-1 yr-1 at F2) and this was largely a result of the increased rainfall in 2004, compared to 2003. Table 3.2 Loads of phosphorus, nitrate and IPU at gauging stations in the

WDWC 2003 - 2004 TP (Kg/Ha) MRP (g/Ha) Date F1 F2 F3 F1 F2 F3 Jan - Dec 2003

0.02 0.09 0.13 3.8 9.1 22.5

Jan - Dec 2004

0.14 0.61 0.72 28.9 86.0 93.9

NO3N (Kg/Ha) IPU (mg/Ha) Date F1 F2 F3 F1 F2 F3 Jan - Dec 2003

1.3 5.8 3.6 66.2 131.4 32.1

Jan - Dec 2004

6.0 18.5 19.1 406.3 *68.2 166.5

* Excludes data for Dec 2004 due to sampler failure Similarly, in 2003, concentrations and loadings of TP were very small in relation to previous studies (e.g. Haygarth and Jarvis, 1999), with reported values c. 100 g TP ha-1 yr-1, to 2 kg TP yr-1, compared to 20 – 130 g TP ha-1 yr-1 at sites F1 and F3, respectively (Figures 3.17 to 3.18). However, in common with MRP, the rainfall in 2004 caused more TP to be found in watercourses at Whittle Dene. The largest loading per ha was at site F3, where 700 g TP ha yr-1 was recorded.

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Figure 3.17 Loads of TP at Whittle Dene (kg)

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Figure 3.18 Loads of MRP at Whittle Dene (g) Concentrations of suspended sediment closely matched those for TP. The guideline value of 25 mg L-1 for suspended sediment under the Freshwater Fish Directive (78/659/EEC) was exceeded in the main burn for much of the year and the average value across all sites and years was 53 mg L-1. It was apparent that rainfall following the dry summer of 2003, and heavy rainfall in the wet summer of 2004, caused large concentrations of suspended sediment in the WDWC. The peak concentration was >500 mg L-1 at site F1 in August 2004, downstream of both grass and arable fields and a livestock holding with hardstandings. Large concentrations were found across the catchment however; at F1 just downstream of gently sloping fields with poor drainage and blocks of forestry, and at F2, downstream of livestock access and rutted vehicle tracks to the Burn. 3.6 Soil Mineral Nitrogen and Phosphorus in fields in the WDWC One of the factors which will determine the concentrations of nutrients in receiving waters will be the amounts of N and P found in the source areas. The levels of N and P in fields in the WDWC can be seen in Figures 3.19 to 3.21. This information, together with pH, K and Mg analyses conducted as part of the soil analyses suite, was provided to the farms concerned.

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Figure 3.19 SMN autumn 2002

Figure 3.20 SMN autumn 2003 Soil Mineral Nitrogen (SMN) in the autumns of 2002 and 2004 showed variations between years. As shown in Table 3.3, in 2002 only 5% of fields sampled were SMN index 1 or 2, whereas in autumns 2003 and 04 over 50% of fields fell into these categories. The majority of fields that consistently fell in the higher SMN indices were under grass, reflecting large organic and inorganic inputs. However, a small number of arable fields also contained consistently large amounts of SMN in the three years they were sampled.

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Figure 3.21 SMN autumn 2004 Table 3.3 SMN Index (0-90 cm) of fields in the WDWC 2002-2004 October 2002 December 2003 October 2004 SMN kg ha-1

SMN Index

No of fields

sampled

% No of fields

sampled

% No of fields

sampled

%

<60 0 0 0 7 23 14 30 61-80 1 2 5 9 30 9 20 81-100 2 7 17 3 10 12 26 101-120 3 11 27 3 10 2 4 121-160 4 7 17 2 7 1 2 161-240 5 10 24 6 20 5 11 >240 6 4 10 0 0 3 7 TOTAL 41 30 46

In February 2003, soil samples were taken to 15 cm deep and analysed for P, K. Mg and pH. The concentrations of P in soil are relatively stable from year to year, and RB209 (MAFF, 2000) recommends that sampling every fourth year is sufficient for fertiliser recommendations. Subject to rotational position, it is planned to take further samples from fields in the WDWC in spring 2005 for research purposes. As can be seen in Figure 3.22 and Table 3.4, the amounts of Olsen P in the WDWC were generally not large. Farm surveys confirm that, in general, only maintenance applications of P were made to both arable and grass fields. The exception to this were grass fields close to farms 1, 3 and 4. These units all contain animals (beef cattle and sheep), and it is probable that the higher P indices of fields close to these units reflects historical manure applications and storage, together with regular animal movements to and from the farm.

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Figure 3.22 P index (Olsens) and cropping spring 2003 Table 3.4 Olsens P index (0-15 cm) of fields in the WDWC February 2003 Olsens P mg L-1

Index No of fields sampled

%

0-9 0 11 23 10-15 1 9 19 16-25 2 20 42 26-45 3 7 15 46-70 4 1 2 TOTAL 48 3.7 Soils and drainage The main soil types identified over the WDWC, and the surrounding area, are shown in Figure 3.23. Three main soil types were identified in the study area, Brickfield, Enborne and Rivington. These soils are described in the following paragraphs, together with supporting information from the soil structural and drainage assessment of the WDWC. Brickfield is the main soil series within the WDWC and covers 302 ha or 86.0% of the study area. These are soils derived from boulder clays (glacial tills) from Carboniferous shales and sandstones. Their texture varies depending on the underlying drift, the soils tend to be loamy where the drift is predominantly sandstone and clayey where it is shale. They have a mean depth of 25 cm of well structured, medium textured topsoils overlying a slowly permeable medium or heavy textured subsoil (Jarvis et al., 1984). Brickfield soils are typically graded 3b for agricultural land classification purposes and soil wetness is the main limitation. Mapped with this series are some of the fields next to the B6318 Military Road, running parallel to the site of Hadrian’s wall, which have a rig and furrow land form and are in permanent grass. Also there are at least two areas where the soils have been significantly disturbed, one in a field south of Vallum farm and a narrow strip, associated with a gas pipeline installation, running east-west, north and east of Shildon Hill Farm. It also includes some areas which are seasonally waterlogged in the east of the site, adjacent to streams or drainage ditches.

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Legend

Brickfield

Enborne

Rivington

Figure 3.23 Soils at Whittle Dene

It is important to evaluate the extent of the main soil type within, and surrounding, the small research catchment. Analysis of published data (Jarvis et al., 1984) and interogation of the NSRI Digital Soils Database, shows that the soil series of the Brickfield 3 Association represent the largest land area in the Pennines and Northumberland (2657 km2, 8.6% of all land area). Figure 3.24 shows the extent of the Brickfield soils in the general area around the research catchment. The soil map shows the dominant soil series in 1 km grid squares. Other soil series will also be present within each grid cell, but the dominant soil series will always cover the largest area within any individual cell.

Figure 3.24 Dominant soil series in the area around Whittle Dene

41

The second soil type in the WDWC is the Enborne series. These are alluvial soils that lie mainly on the southern side of the Whittle Burn and they cover a total of approximately 15 ha or 4.3% of the study area. They are loamy textured with significant silt or fine sand content in both the top and subsoil. Although they appear to be well structured and capable of draining freely, strong gleying and mottling in the subsoils and lower topsoil suggests that they are strongly influenced by high groundwater at Whittle Dene. The gleying indicates that these soils stand waterlogged for long periods of time and would be unsuited to spring cropping. These Enborne soils would be graded 3b in the agricultural land classification system and their main limitation is soil wetness. Finally, the Rivington series is also found at Whittle Dene and these are freely draining stony and sandy soils. Rivington soils are found on the elevated ridge on the South and Western edge of the site. They cover approximately 34 ha or 9.7% of the study area. Rivington soils cover a wide range of agricultural land classification grades between 3a and 4. They are limited by high stone content, susceptibility to drought and typically occur on steep slopes. Rivington soils are commonly used for permanent pasture and woodland/ heathland, as on this site. Data on the drainage that took place from the 1950’s to the 1990’s was collected by the former MAFF Divisional Offices. Figure 3.25 shows how the amount of drained land varied over a 40 year period for Alnwick Division, Northumberland which covered an area of 5209km2. There are two peak drainage years in 1976 and 1982. After 1982, as the grant aid was removed, far less in-field drainage took place and the amount rapidly reduced to negligible amounts by 1992. The most detailed information on the characteristics of the drainage systems was collected during the 1971-1985 period when the most modern and effective drainage systems were installed.

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Figure 3.25 Agricultural field drainage in the Alnwick Division 1951 to 1991

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General aspects on the drainage systems at Whittle Dene were abstracted from the drainage database. Forty parishes in the Whittle Dene area were assessed against the larger database for the whole of Northumberland and these data can be seen in Table 3.5. 70% of the in-field drainage schemes in Northumberland, and in the Whittle Dene area used clay pipes. The average in-field drain spacing was c. 10 m. The average in-field drain depth was c. 70 cm below ground level. Over 80% of drainage schemes are not recorded as using proper permeable fill (such as gravel) to cover the pipes in the drainage trenches and the majority of the schemes did not employ secondary treatments, such as subsoiling and mole drainage. Peat or turf was sometimes used as a permeable backfill in fields around Whittle Dene (14% in Parishes around Whittle Dene, against 7% in Northumberland). Discussions with local drainage contractors and ADAS drainage advisors revealed that it was common practice to "blind" the drains with a turf laid up side down over the pipe. This was basically to protect the pipe, particularly clay tiles, when the spoil was pushed back into the trench. It was also said to act as a filter against silting. The soils in the area around Whittle Dene are mainly silts and clays, so they will compact back down over the pipe in a matter of years, though a retired drainage officer held that the Brickfield clay soils cracked vertically so p.f. was not needed. This has implications regarding by-pass flow and preferential transport of a range of potential pollutants in early autumn after a dry summer. Peat would only be used to backfill the drains when draining areas where it was present. It was not was imported specifically as p.f. It was considered that, as peat dried out and gradually shrank, the tiles would go out of line in 6 to 10 years, or ‘rise’ to the surface. In deep peat, the pipes were often laid on boards which eventually rotted. These situations cause significant drainage problems, especially where there were drains running from outside into the peat area. Ochre could also be a problem where peat was drained. This can ruin a scheme in 3 years if the drains are not jetted regularly. Though there are no large areas in the WDWC, there are organic soils in the vicinity, and these problems should be considered when identifying drainage problems in the area. 3.8 Surface and subsurface flow Atypical weather conditions during 2003 in the form of very dry conditions caused significant problems with the piezometers installed at field S9. Piezometers will be most useful in this cracking Brickfield soil when subsurface flow is homogenous and is via the soil matrix, i.e. when the soil is close to field capacity for extended periods in winter and spring. Macropore cracking was especially evident throughout autumn and winter 2003 and few samples were collected throughout the year due to the dry conditions. This work is continuing. The subsurface water levels in piezometers showed a rapid response to storm events. This reflects the very impermeable clay subsoil and low infiltration capacity (Section 3.7). Figure 3.26 shows the level of water in selected piezometers in field S9 and it can be seen that the water table rose to within 10 cm of the soil surface. This clearly shows the mechanisms of near subsurface flow, and potentially, overland flow. The position of the piezometers relatively close to the burn at the foot of a shallow slope supports the assumption that saturated overland flow is dominant at this location.

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Table 3.5 Drainage pipe type and permeable fill type numbers and percentages installed in Northumberland and Parishes around Whittle Dene Northumberland WD Parishes PERMEABLE FILL TYPE CODES Number % Number % No entry on application form 0 0 0 0 0 None used 1 2026 88.6 397 82.0 Washed gravel, crushed stone 2 93 4.1 20 4.1 Reject gravel 3 3 0.1 2 0.4 Clinker 4 0 0.0 0 0 Straw 5 0 0.0 0 0 Slag 6 0 0.0 0 0 Peat or turf 7 163 7.1 64 13.2 Hard synthetics e.g. Lytag, Leca

8 0 0.0 0 0

Soft synthetics e.g. polystyrene 9 0 0.0 0 0 Others 10 2 0.1 1 0.2 TOTAL 2287 484 Northumberland WD Parishes PIPE TYPE CODES Number % Number % Clayware 1 1754 74.5 411 74.0 Concrete 2 136 5.8 25 4.0 Glazed stoneware 3 66 2.8 19 3.0 Smooth plastics in polyethylene 4 1 0.0 1 <0.1 Smooth plastics in PVC 5 7 0.3 0 0 Smoth plastics in other material 6 0 0.0 0 0 Pitch fibre 7 0 0.0 0 0 Corrugated plastics in PVC 8 390 16.6 102 18.0 Other corrugated plastics 9 0 0.0 0 0 Filter-wrapped pipe 10 0 0.0 0 0 Others 99 0 0.0 0 0 TOTAL 2354 558 Average drain spacing m m

10.2 9.8 Average drain depth cm cm 71 78

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Targeting key locations could enhance successful mitigation options to minimise delivery at edge of field. The results of the flow accumulation mapping, together with photographs of the field from two locations can be seen in Figure 3.27. Though the image taken to the west of the field looks dramatic, it should be noted that this overland flow is thought to be largely from a breakdown in underdrainage. The image from the east of the field shows a layer of fine soil particles at the soil surface which represents a source of sediment, and associated phosphorus, to the Whittle Burn. Work to determine if there are differences in concentrations of P in areas of flow convergence compared to other areas of the field is continuing.

200 m

Whittle Burn

direction of flow

N

Figure 3.27 Flow accumulation map for field number ‘F9’ and photographs

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3.9 Vegetation survey Most of the species found during the vegetation assessment conducted in July 2003 were found in either wet/damp habitats or rough grassland/roadside habitats, although woodland/scrub species were also represented. This is to be expected. Other species, such as Galium verum, were found only occasionally and in specific areas and were not representative of the majority of the bank side vegetation. The species listed in Appendix 1 are not a definitive list, but were the most relevant in terms of a) their frequency/abundance and/or b) the habitats found at Whittle Dene. While rank grasses and tall herb species were present at most points along the burn, the bank-side vegetation immediately downstream of site F2 was more interesting. Whilst rank grasses and tall herb species were still present, species more reminiscent of a less agriculturally improved habitat are also found. Lathyrus pratensis (Meadow Vetchling), Achillea millefolium (Yarrow), Achillea ptarmica (Sneezewort), Sanguisorba officinalis (Great Burnet), Potentilla erecta (Tormentil), Galium verum (Lady’s Bedstraw), Lotus corniculatus (Common Bird's-foot-trefoil), Centaurea nigra (Black Knapweed), Stachys officinalis (Betony) and Conopodium majus (Pignut) were all recorded. None of the identified water plants had an Ellenberg F Index > 10. Index 10 is an “Indicator of shallow-water sites that may lack standing water for extensive periods”. Other than two species (including G. verum), all recorded species had a F Index > 5 (“Moist-site indicator, mainly on fresh soils of average dampness”). Apium nodiflorum was the most frequently observed of the aquatic species (classed as F Indexes 9 and 10 here); it also had a N Index of 7 – “Plant often found in richly fertile sites”. Veronica beccabunga and Catabrosa aquatica also had an N Index of 7, but three of the other four ‘aquatic’ species had N Indexes of 4 which is suggestive of only an intermediate fertility. The vegetation assessment suggested that most of the aquatic species would survive under eutrophic (high nutrient) conditions. Only Glyceria fluitans, which is described as mainly mesotrophic, is the exception. None of the species would be found in only oligotrophic (low nutrient) conditions, however. This assessment supports the findings of the water quality monitoring survey and the modelling results. 3.10 Aquatic survey The mean relative abundance of taxa is presented in Appendix 2, showing differences in community structure between the five sampling locations. Samples were identified to family level (Oligochaete worms to class). BMWP (Biological Monitoring working Party) and ASPT (Average Score Per Taxon) scores were also calculated to determine the invertebrate diversity at each sample site. Samples were analysed from three of the seven sites surveyed in May and both sites surveyed in September. Descriptions of the habitat types are given in Table 3.6 below. The dominant taxon were Gammarids (Gammarus pulex) (Freshwater shrimp) composing ~40% of samples from sites 1, 7 and 9, 22% at site 8 and 11% at site 4. Other abundant taxa were Baetidae (Mayflies) in May (9 – 16% of samples in sites 1, 4 and 7), Glossosomatidae (Caddisflies) (Agapetus fuscipes) at site 4 in May (23% of sample) and Scirtidae (Beetles) (19% at site7 and 26% at site 9). All other taxa composed of less than 10% of sample.

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Table 3.6 Habitat types at sampling locations along Whittle Burn Site 1 Stony substratum with riffles and partial shading from tall tree cover,

<200 metres from reservoir complex. Site 4 Stony substratum with some vegetative detritus, downstream from

straight course at edge of arable field. Site 7 Silt-mud substratum, immediately downstream from coniferous

plantation, <500 metres downstream from source of stream. Site 8 Shallow pools with stony substratum and mud with partial shading

from tall tree cover, ~ 1km from source of stream. Adjacent fields with stubble.

Site 9 Shallow pools with stony substratum and overhanging vegetation, ~600 metres from reservoir complex. Some aquatic grasses present. Adjacent fields with stubble.

To illustrate the difference in taxa according to respective BMWP scores, taxa with similar score allocations were pooled together (Table 3.7). From this, it was found that between 45 and 63% of samples collected at sites 1, 7, 8 and 9 consisted of organisms allocated with a BMWP score of 6. All of these specimens were Gammarus pulex. For sample sites 1, 4 and 7, there was a greater proportion of sample with BMWP scores greater than 7 than there were with BMWP scores less than 4. Sample sites 8 and 9 had proportionally more specimens with BMWP scores less than 4 than higher (>7) scoring specimens. Table 3.7 Proportion of organisms collected with similar BMWP scores for each site

Sum of organisms found according to BMWP score (n) at: BMWP score Site 1 Site 4 Site 7 Site 8 Site 9 1 7 1 2 0 0 2 0 10 7 4 5 3 1 4 3 32 21 4 12 10 3 0 7 5 6 9 50 13 37 6 46 13 83 70 131 7 5 14 15 4 4 8 6 0 4 0 0 10 3 11 20 23 5

Weather conditions were very dry between May (1st survey) and September (2nd survey) and the Whittle Burn dried out during the period before the second sampling survey. This resulted in survey methods deviating from those agreed where standard methods of sampling could not be used to collect samples. Also, most of the watercourse was found to be dry from late August to early October, and so sampling sites were different on each of the surveys. If pools remain over dry periods in watercourses, then they will act as reserves for re-colonisation once wet conditions return. Fresh water macro-invertebrates may survive dry periods by responding in different ways. Mobile insects such as adult bugs and beetles can fly to other water bodies and return after rainfall. Snails can migrate to wet areas over land, and small bivalves and crustaceans can migrate to ground water for refuge (within interstitial spaces in soils).

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Many insect larvae are intolerant of prolonged dry conditions. These groups include caddis-flies (Trichoptera), stoneflies (Plecoptera), mayflies (Ephemeroptera) and dragonflies (Odonata). Freshwater shrimps and crayfish may also be subject to exposure in this way. Three sampling sites were surveyed in May, while only two sites (at different locations to the previous three sites) remained sufficiently wet to sample in September. This resulted in there being five sampling sites over the two sampling visits. As sampling was inconsistent over the two visits it is not possible to compare May results directly with September results but some trends can be found by comparing the samples from the two periods. Biotic scores provide an indicative assessment of water quality by taking into account species present in water bodies. BMWP scores have been adopted in UK water quality assessment and are used in this survey to compare samples from the different sites. BMWP scores varied significantly between sampling sites (4 d.f., p<0.005; Appendix 2). This is a consequence of patchy distribution of taxa along the stream, variation in diversity over time and/or of environmental change (where conditions became drier later in the year). The BMWP Score for sampling site 7 was much higher than that found for sites 4 and 1, showing a decrease at the sites further downstream, where arable land-use may have influenced water quality. BMWP scores for both sites 8 and 9 (sampled in September) were similar though these were isolated pools. Both sites surveyed later in the year were also situated in areas of arable land-use. No survey was conducted near site 7 in September, as the stream bed was dry. The proportion of samples with BMWP scores ≥ 6 was more than 50% at all sites, showing that all sites were generally of good water quality (Fig.2). The dominant species was Gammarus pulex, an indicator species of good water quality. Another biotic score calculated was the average score per taxon (ASPT). This score is less influenced by season and sample size (Mason, 1996) thus providing a more reliable value of biotic score, when comparing data from different surveys. ASPT values varied between the two survey dates. Sampling sites 1, 4 and 7 had a higher ASPT (6.00 ± 0.50) than the values for sites 8 and 9 (~4.50), sampled later in September. This may have resulted from the dry weather causing increased stress in the aquatic biota and hence a decrease in less tolerant species. ASPT for sites 1, 4 and 7 varied significantly to each other (4 d.f, p < 0.001) where sites 1 and 7 showed higher scores. Although all three sites were sampled using the standard method, the watercourse differed at each site, being narrow with overhanging vegetation upstream and much wider and less vegetated down stream. Stoneflies (Plecoptera) were most common in May at the upstream sampling site (Site 7). This is where the Whittle Burn enters arable land and is immediately downstream of a coniferous plantation close to sampling point F1. No stoneflies were found in September but this may be due to the life history of many of the British species, which live from egg to adult in one year. Most species are at the egg stage of development in late summer and so, though they may have been present, these were not found in the later survey. Caddis-flies became less abundant in September. Caddis-cases were found attached to stony substrata but appeared empty, as adults may already have emerged. One species of Limnephilid caddis-fly was present in September while ten families were found in May. It is possible that the caddis-flies were a group adversely affected by dry conditions later in the year, though many species may already have emerged by then and remaining life stages would be either eggs or early instars.

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The only mayfly to occur in samples in September was Ephemera danica, a large species of mayfly which can adopt a life history strategy covering one, two or three years. Therefore, this species would still be present later in the year. However, Baetid, Leptophlebid and Heptogeniid mayflies were absent on the second survey but these families would normally be present as larval stages in late summer. It is possible that dry conditions and the reduction of water caused these families to decline in the larval and possibly, egg stages. Molluscs were more abundant at sites 8 and 9. Lymnaeid and Hydrobiid molluscs were almost absent from samples at sites 1, 4 and 7 in May but were more frequent at sites 8 and 9 in September. However, some of the records were shells as well as live individuals, at the time of collection. It is likely that there was a higher incidence of these families in September due to dry summer conditions, where water snails moved to the water recesses for refuge. Sphaerid molluscs were absent at site 1, which had a predominantly stony substratum. Families of bugs and beetles were present at sites 8 and 9, in September. Similarly, these groups are able to move quickly in response to adverse conditions and changes to habitat (as discussed above). The families: Gerridae (pond skaters); Velliidae (water crickets), and; Mesoveliidae are all surface dwelling bugs which live and prey or scavenge on the water’s surface-tension. These bugs are less directly affected by the dry conditions and some adult forms are winged, enabling migration to other water bodies. Corixids (water boatmen); Notonecta glauca (backswimmers), and; Nepa cinerea (the water scorpion) are also capable of flight in their adult stages. These families were absent from site 1, which had no vegetation and a turbulent current, presenting unsuitable conditions. Scirtid beetles were abundant at site 7 as adults and larvae and present at sites 8 and 9 later in the year as adults. Site 7 was set adjacent to coniferous woodland, which might create different water properties (lower pH) in the stream. Less emphasis was placed on oligochaete worms and true flies as these taxa are relatively common in all aquatic habitats. However, it was noted that both Oligochaetes and Chironomidae were present and frequent at all sites. Other true fly families were evident but not in any great abundance.

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4. DISCUSSION 4.1 Objectives This section of the report discusses the issues relating to water quality problems that have been investigated in the WDWC. The generic principles of catchment management, for purposes such as water quality and water quantity (flooding and water resources) can be summarised in the following logical steps:

1. Identify the catchment 2. Characterise the catchment 3. Devise additional monitoring as required 4. Identify the environmental stresses 5. Identify appropriate measures to improve standards and the instruments with which to introduce them 6. Ensure that the measures and instruments are introduced as a coherent plan with due regard to other sectors 7. Monitor 8. Review and revise methods, measures and the plan (Modified from Willett and Porter, 2001)

After planning and instigating monitoring regimes for water, soils and farm management, the Whittle Dene Project has continued as planned. Years one and two of the project have focussed on detailed monitoring of a small, but representative, catchment that had recognised, but unquantified, water quality problems. Section 3 described the results of water quality monitoring, including the frequency and magnitude of several key parameters (nitrate, phosphorus, faecal indicators, suspended sediment and pesticides) that were measured in the watercourses of the catchment. The potential source, transport and delivery of these diffuse pollutants were also reported as results from detailed catchment investigations. Measures and Instruments are available to reduce the loads of diffuse pollutants to watercourses and these often have secondary benefits for agricultural productivity and for the wider environment. Thus, the objective of Section 4 is to consider the results for the characterisation and monitoring (points 1 to 4, above) before describing the recommended actions (points 5 to 6, above) in Section 5. Agriculture in the catchment is mainly mixed livestock and arable, with a conversion of a mixed farm to a dedicated arable unit in the 1990’s. The WDWC also contains a number of small woodland plantations. The discrete size and nature of the Western Catchment makes it particularly suited as a unit to undertake detailed monitoring and field experiments. The larger Whittle Dene to Hallington catchments (approximately 300 km2) offers potential to apply principles learned from detailed work conducted in the Western catchment, and to transfer information to a larger scale. This could be particularly important if the general trend to larger farm units with more arable land continues northward into this area. 4.2 Pesticides As discussed in Section 3.3, there has been an apparent increase in pesticide (especially agricultural herbicide) detections and exceedences above 0.1µg L-1 in recent years. It was important to investigate the reasons for the observed increases in pesticide concentrations at Whittle Dene. First, it should be pointed out that, in common with nitrate, the historical monitoring results may not be representative and can miss peaks in concentrations. Since IPU is only applied to arable land used for cereals, it was important to examine the proportion of land used in this way.

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Figure 4.1 shows the proportion of arable land in the Parishes around the Whittle Dene reservoir complex from 1970 to 2000. The shift towards more arable land in a northerly direction from the Tyne Valley is very apparent. In the WDWC, the proportion of arable land increased by up to 40% in the thirty years analysed and the increase was particularly apparent between 1980 and 1995. However, it cannot be assumed that the relationship between arable conversion and a perceived decline in water quality is straightforward. There are many potential reasons, such as weather conditions, specific farm and field management practices, critical source areas being brought into production or problems of specific chemicals. All of these factors should be investigated to fully consider the true causes and effects such that a managed and balanced response can be devised.

Figure 4.1 Average arable area (%) in parishes around the Whittle Dene Western Catchment 1970 – 2000 It was important to understand the likely extent of the area responsible for large concentrations of herbicides in watercourses around Whittle Dene. The SWAT model (Brown et al., 1996) was used to assess the likely risk of IPU leaching from arable soils in the Whittle Dene area after a typical autumn application of 1.5 kg a.s. ha-1. SWAT is a semi-empirical model based upon a direct hydrological link between soil type and rainfall, pesticide characteristics and attenuating factors. The model output can be seen in Figure 4.2, which also shows the approximate extent of the WDWC.

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Figure 4.2 Predicted risk of IPU leaching to watercourses in an average autumn As can be seen in Figures 4.1 and 4.2, the ‘high risk’ areas closely match the arable areas, which are generally on soils of the Brickfield and Dunkeswick association, both of which share common hydrological properties (see Section 4.6). Approximately 34% of the modelled area was considered to be at high risk of IPU loss to watercourses in a typical autumn. As described in Section 3.5.1, of the pesticides monitored at Whittle Dene, isoproturon was the most frequently detected, followed by propyzamide. Peaks in IPU occurred shortly after application, and usually, but not exclusively, followed rainfall. There were also isolated, but potentially significant, detections of the insecticide cypermethrin. It was important to place these detections in a national context. The EA monitors approximately 1,770 freshwater sites across England and Wales for 250 pesticides. (EA, 2003). The limit for any individual pesticide intended for potable supply in surface waters is 0.1 µg L-1 (100 ng L-1), and the limit for a combination of pesticide substances is 0.5 µg L-1 (Drinking Water Directive 80/778/EEC). These limits were primarily designed to protect potable water supplies, and were in effect surrogates for zero at the time they were devised. The Environmental Quality Standards (EQS) for pesticides are designed to protect the aquatic ecology of a watercourse and are based on detailed toxicological studies. Thus, the EQS can be greater, or less than the 0.1 µg L-1 limit. When considering pesticides in watercourses, it is important to examine concentrations of substances in relation to the drinking water standards and the EQS. An EQS is the concentration of an individual substance that should not be exceeded in surface freshwaters and/or marine waters on the basis of its toxicity to the aquatic environment. The EQS is established using available toxicity data, and can be either an annual average (AA) concentration or maximum allowable concentration (MAC) designed to

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highlight long-term and short-term exposure respectively. EQSs have been set for approximately 70 pesticides, some as a result of EU legislation (statutory EQSs) and some as a result of particular environmental concerns about a pesticide (operational EQSs). The issue of individual EQS for specific pesticides vs the 0.1 µg L-1 limit for potable water is a difficult subject to communicate effectively to the general public. However, with the WFD aiming to tackle water quality in a coherent manner, these issues will become more important. Thus, there is need to examine the messages that need to be portrayed to the general public, landowners and farmers. Phase II of the Whittle Dene Project presents an excellent forum to do this. Figure 4.3 shows the 10 pesticides most frequently exceeding 0.1 µg L-1 in surface freshwaters in 2002 (EA, 2003). As in previous years the vast majority of the substances were either solely or mainly used for agricultural purposes, suggesting that agriculture continued to be the main source of freshwater pesticide pollution. All are widely used, relatively mobile and persistent herbicides with high dosage rates. In 2002, the non-agricultural herbicide diuron occurred most frequently, with the agricultural and amenity herbicide mecoprop second and IPU third.

Figure 4.3 Ten most frequently occuring substances in surface water >0.1 µg L-1 (EA 2003) In 2002, 122 of 1773 sites failed the Environmental Quality Standard (EQS). The most common EQS failure was cypermethrin, and this was ascribed to use as a sheep dip or pour-on product. As discussed in Section 3.5.1, cypermethrin was detected at concentrations up to 190 ng L-1 at Whittle Dene, compared to a MAC of 2.0 ng L1. The detections at Whittle Dene were in late autumn and early spring, and coincided with application of cypermethrin as a cereal insecticide. Thus, the source of cypermethrin in watercourses should be carefully examined and it cannot be assumed that all detections will be as a result of animal use. The movement of pesticides to watercourses has been well studied, (e.g. Williams et al.,1995; MAFF, 2000). After reviewing the literature, Gaynor et al. (1995) summarised that the highest concentrations of pesticides in surface runoff or tile discharge typically occur in

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events soon after pesticide application. The risk of contamination is greatest: a) if there is precipitation shortly after application, or b) on fields with slopes greater than 3%, and c) where pesticide application rates are high. On level ground, more pesticides were lost from surface and near-surface runoff than from tile drainage. Cypermethrin is strongly adsorbed by soil particles and has a low solubility. The sorption of synthetic pyrethroids (SPs) to soil does not, however, discount their movement either through macropores down the soil profile or their entry into surface waters, whilst attached to soil particles. For example, Harris & Hollis (1998) conducted work on three small catchments using adsorbent pesticides with low leaching potentials and found that particulate transport via macropore cracking to field drains could be a significant loss route. Most of this particulate load was carried in the streams early in runoff events. The Brickfield and Dunkeswick soils of the Western subcatchment are prone to cracking and, following the very dry summer and autumn of 2003, macropore flow is likely to have been significant. These soils also cover large areas of North East England (Jarvis et al., 1984) and hence, this loss pathway may be important. In Phase II, it is important to continue to work on these soils to further the understanding of insecticide losses to watercourses. Current national monitoring programmes will not detect such localised, but potentially important, concentrations in small streams and tributaries. Monthly monitoring of higher order streams is unlikely to detect such incidents, and it could be argued that the impact on small tributaries and their ecology in the semi uplands could be disproportionally high. In contrast, the apparent ineffectiveness of underdrainage at some locations where cypermethrin was known to have been applied causes some questions to be raised as to the likely transport of sediment and adsorbed cypermethrin in spring 2004. If drains were not running, how did rapid transport of a sediment bound substance contribute to concentrations found in the Whittle Burn? First, macropore cracking early in the early drainage season may have allowed particles to be transported to drains that were still functional while water levels in the ditch were still low. Subsequently, as the water level in the silted ditch rose, the drain quickly became submerged. This would cause the water to back-up in the field, with slow, or minimal flow that would be dependent on the hydraulic gradient. Secondly, in spring, after the soil had wetted up and the soil cracks had closed, there are several locations where drainage has almost completely broken down. Under these circumstances overland and near-surface flow will predominate causing localised soil erosion, which will transport strongly adsorbed substances, such as cypermethrin (Plate 4.1). This is discussed further in Section 4.6. With regards to pesticide exceedences above the 0.1 µg L-1 limit in England and Wales, herbicides were the most commonly occurring substances. In 2002, the non-agricultural herbicide diuron was the most frequently occurring pesticide in surface waters, with the agricultural and amenity herbicide mecoprop second, and the cereal herbicide IPU third (EA, 2003). In 1999-2000, IPU was the most extensively used herbicide active substance in England and Wales, applied to c. 2,661,800 ha of arable crops in 1998 (Garthwaite, 2000). Compared to cypermethrin, the more mobile substances such as the herbicides IPU and propyzamide, are likely to be lost primarily in solution. Though effective underdrainage can increase losses of substances such as IPU (e.g. Williams et al., 1995; Jones et al., 2000), Brown et al. (1995) reported that losses of autumn applied herbicides were up to four times greater from an undrained plot compared to a mole drained plot on the Brickfield soil (as found at Whittle Dene). Mole drainage decreased movement of pesticides from this slowly permeable soil by reducing the amount of surface layer flow.

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Thus, it is considered that soils and drainage contribute significantly to the risk of diffuse pesticide losses to watercourse at Whittle Dene. There is no evidence that farmers are using pesticides irresponsibly or against recommendations. However, the use of some marginal fields for arable production could be questioned. This is not unique to Whittle Dene, and poor grade agricultural land is frequently used for arable production despite limitations due to drainage, soil characteristics, or slope, for example. Under these conditions, a factor in the success of ES might be how many of these fields are reverted to permanent, low input grassland. There are several potential sources and transport methods of pesticide substances to watercourses in addition to diffuse sources from fields (Table 4.1). This shows that point sources, especially from handling and washdown areas, can be significant in pesticide losses to watercourses. For example, Mason et al. (1999) found that the total contribution of IPU from a handling and washdown area in the Cherwell catchment, UK, peaked at 23,000 µg L-

1, and the total load was sufficient to cause the concentration of IPU to rise to 13 µg L-1 in the River. At Whittle Dene, there is only one potential pesticide handling area that drains directly into the WDWC and this would eventually drain via sampling point F3. All sampling points monitor water flowing from arable land to which IPU and other herbicides are applied. Thus, diffuse sources are likely to be dominant. However, it is important not to neglect handling and washdown areas as a potential source of pesticides to watercourses, especially in a research catchment where pesticides are a significant issue. It is therefore proposed to address this issue via a demonstration ‘biobed’ handling area on a farm where the yard drains just outside the monitored area of the WDWC (see Section 5). Table 4.1 Routes of environmental contamination by pesticides Diffuse Point and semi-point Spray application and drift Tank or container filling and mixing Soil/sediment accumulation, uptake by crop/plants/non-target biota

Spillages

Volatilisation and precipitation Washoff (treated surfaces and animals) Contaminated manures and waste Faulty equipment Surface runnoff and sediment transport Washings and waste disposal Leaching (soil, treated surfaces and animals) Sumps, soakaways and drainage Throughflow Direct contamination (including overspray) Drainflow Consented discharges Baseflow Un-consented discharges River discharge to estuary and marinewaters Incidents (fires, vandalism) (Source: Environment Agency, 2000) The issue of spray-drift cannot be discounted, but available spray records do not show spraying days coinciding with water sampling occasions and large concentrations in watercourses. Available records show that farmers and contractors follow LERAPS and it is important to ensure that up to date information on best practice is followed. Thus, the work at Whittle Dene has identified potential substances that were likely to be detected in the catchment, out of approximately 250 potential substances. It is acknowledged that other substances are likely to be present in watercourses at Whittle Dene, but attention and resources have focussed on a subsection that are known to be causing problems for drinking water abstraction (e.g. IPU and propyzamide), together with a potential EQS failure (i.e. cypermethrin). The suite of pesticide substances analysed at Whittle Dene will be reviewed in Phase II. It is recommended that the analyses for carbofuran are suspended. Carbofuran has not been detected during the project and its

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approval for use has been withdrawn (see Section 2.8). It is also recommended that selected summer applied grassland herbicides are added to the analyses suite. The widely used and frequently detected cereal, grassland and amenity herbicide mecoprop-P is a likely option. Historical data was used to guide the selection process, together with local knowledge and agronomic experience. Monitoring has shown that there is a large area of the WDWC that is responsible for diffuse pesticide losses to watercourses. This potentially makes a response more difficult, since an individual hot-spot, such as a high-risk field or poorly sited and operated pesticide handling area would enable a focussed response. Analysis of land use has been used to investigate potential causes for the apparent increase in pesticide (especially agricultural herbicides) in watercourses in the area around Whittle Dene. Following on from this, the area around Whittle Dene was modelled to predict the likely risk of IPU losses in an average year with arable land area from 2000. The reasons for losses of substances with diverse characteristics (i.e. IPU compared to cypermethrin) were investigated and these appear to be related largely to land use and soil management. 4.3 Microbial Indicators Several studies have identified domesticated farm animals as a source of faecal organisms to watercourses and, in particular, bathing waters in the UK, e.g. Aitkin et al. (2001). There are relatively few studies which have measured concentrations of faecal indicators in headwater streams and less that have monitored faecal contamination of watercourses in small, agricultural catchments over successive seasons. However, it is important to investigate the source and transport of faecal material to watercourses in order to devise management strategies to protect amenity and bathing waters. Potential source areas such as the WDWC represent an important avenue of investigation, as there are few potential sources beyond domestic and wild animals to complicate the situation. There are no specific pieces of legislation that specify or advise what concentrations should be sought in small headwater streams or rivers. There are, however, two pieces of legislation relating to concentrations of pathogens in water; the Surface Water Abstraction Directive (75/440/EEC) and the Bathing Water Directive (76/160/EC). The Bathing Water Directive is designed to protect the environment and human health where waters are used for bathing. Under this definition, the Whittle Burn and Reservoirs would therefore be excluded. Nevertheless, it is a useful guide as to desirable concentrations. For example, if a large proportion of agricultural tributaries to a major river system contained concentrations of this magnitude, then bathing water limits might potentially be breached. The Imperative Limit is 1,000 FC 100 ml-1, and the Guideline Limit is 100 FC 100 ml-1. Bathing Water Directive is currently being revised and the limits are expected to be reduced. The Commission has proposed a minimum bathing water quality standard (the "good quality" standard) of 200 intestinal enterococci per 100ml at 95 percentile compliance and 500 E. coli per 100ml at 95 percentile compliance (CEC, 2002) Under the Surface Water Abstraction Directive 75/440/EEC (CEC, 1975), raw water quality is classified to determine the level of treatment required before it is suitable for public supply. Thus, the limits in raw (i.e. untreated water abstracted from surface and groundwater) are stepped, depending on the effectiveness of the WTW concerned. The respective limits are either 20, 2,000 or 20,000 Faecal coliforms (FC) 100 ml-1 depending on the type (and effectiveness) of the treatment process. It should be noted that although the concentrations of FC at Whittle Dene exceed the most stringent of these values for several months each year, the water concerned is stored in reservoirs before being abstracted for subsequent treatment and distribution. The storage of water in this way is effectively a treatment process and concentrations will be reduced during this time.

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The maximum concentrations of Faecal Coliforms (FC) at Whittle Dene were c. 100,000 cfu 100 ml-1 in summers 2003 and 2004. These concentrations are greater than that reported by Hunter and McDonald (1991), who found concentrations up to 750 FC cfu 100 ml-1 after monitoring a low-intensity sheep grazing system in the Yorkshire Dales, UK. Results were, however, of the same magnitude as those of Hunter et al. (2001) who monitored a more intensive sheep grazing system in Derbyshire, UK, and found concentrations up to 144,000 FC cfu 100 ml-1. Similar values were also reported by Aitkin et al. (2001) in the Irvine and Girvan catchments, Scotland, where a maximum of 150,000 and 120,000 cfu 100 ml-1 were reported. The variations in concentrations in these catchments were considered to be largely attributable to livestock density. Howell et al. (1995) monitored concentrations of FC in surface and runoff water from an area of Kentucky, USA, which included beef and dairy cattle grazing. Peak concentrations were 32,200 cfu 100 ml-1, which were of similar magnitude to concentrations during 2004 at Whittle Dene. The two protozoans which are most commonly associated with diarrhoeal disease in humans are Giardia and Cryptosporidium (Pell, 1997). In surface waters, concentrations of Cryptosporidium oocysts and Giardia cysts often correlate (e.g. LeChevallier et al., 1991). The analyses of water to determine concentrations of Gardia and Cryptosporidium parvum oocysts is arduous and expensive. For example, over 10 L of water is required for a single analysis, creating logistical difficulties when operating from remote field sites. The analytical procedure of filtration and counting is also expensive, such that the determination of Cryptosporidium in surface water studies is rarely conducted. Cryptosporidium oocysts concentrations in the soil are largest in the topsoil and are usually transported via overland flow (e.g. Trask and Kalita, 2004), but it is considered that macropore cracking and resultant preferential flow can also be a transport route, especially over underdrainage. There are two possible explanations for the decrease in concentrations of Cryptosporidium oocysts between sites F1 and F2. First, it is possible that the high concentrations at F1 were part of a peak travelling downstream that was yet to pass through sampling point F2. Secondly, it is also possible that concentrations were reduced naturally by settling en-route downstream. At Whittle Dene, farm information was useful in determining major livestock movements, but land rented and grazed on short term agreements was commonplace and grazing dates with animal numbers were difficult to acquire. It was also very difficult to get exact information on livestock grazing when movements occurred frequently within the farm boundary. However, fieldwalking was undertaken to identify the potential ‘high risk’ sites responsible for large concentrations of faecal material in the Whittle Burn. It was easily apparent where animals were grazed frequently.

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Several high-risk sites were highlighted and these are marked by red dots in Figure 4.4. Site ‘A’ was a wet depression at the head of the Whittle Burn where stock had access for watering. Various open drains were also present. Stock had puddled the soil and direct daefication to the watercourse was observed. Approximately 320 ewes and 520 lambs grazed this western edge of the catchment for most of the spring and summer. Similarly, at site ‘D’, livestock frequented a seasonally wet depression at the start of an open ditch which then flowed through an arable field to monitoring point D3. At site ‘B’, cattle were able to water directly from the burn. At site ‘C’, water from a farmyard housing livestock was able to run into an open field drain. Site ‘E’ was a fenced field corner specifically designed to allow stock watering and while this prevented direct access to the burn, it remained a significant potential source of faecal material. Finally, at site ‘F’, an historic ‘cundy’ drain (a stone built underground channel) received water from grazed fields, before discharging at monitoring point D1. Approximately 135 ewes and 240 lambs, and 30 beef cattle grazed this area during 2003.

FD

C

E

AB

Figure 4.4 Map of main sources of faecal material at Whittle Dene Clearly, some of the transmission routes of FIO to watercourses were not straightforward. Some sites were only identified by field walking and the historical drainage systems (with no records) were difficult to identify. While farmers and landowners often knew of their existence, precise details were not forthcoming. This situation is common over much of the UK and should be borne in mind when considering diffuse pollution and farm planning. Farm survey results indicated that few fields received manure applications during the study. Manure was applied to one field in 2003, and to four fields in the north west of the catchment in 2004 (two high application rates in July, at 47 t ha-1 of old cattle manure, two in September, at a rate of 10 t ha-1 ‘humix’). In a comprehensive review, storage is recognised as a very effective way of reducing pathogen levels in manure and the stabilised product will also contain a greater proportion of slowly available plant nutrients, thus presenting a reduced pollution risk compared to fresh manure (Nicholson et al.,2000). The applications of composted ‘humix’ and the well stored cattle manure are unlikely to have greatly influenced the FIO concentrations at Whittle Dene, indicating that direct daefication was probably the primary source of FIO.

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There are three main potential sources of fresh FIO to watercourses, namely wild animals, domesticated animals and humans (e.g. septic tank discharges). Since these sources require different responses in order to reduce concentrations in water, it was important to distinguish between these sources. Catchment surveys revealed only a handful of small domestic dwellings that were likely to have a septic tank in the WDWC. The most significant of these were from the livestock farm which potentially could drain to monitoring point F3, and a domestic house which could drain via a pipe through an arable field to monitoring point D3. Thus, domestic inputs in this particular catchment were not considered to be a large proportion of total loads of either nutrients or FIO, but were monitored nevertheless. Several studies have used the faecal coliform: faecal streptococci ratio as a method to distinguish between faecal contamination of water by humans, domestic animals and wild animals (e.g. Hunter et al., 2001; Howell et al., 1995; Doran & Linn 1979; Geldreich, 1976). FC:FS Ratios >4 are considered to be mainly from human sources; FC:FS 0.1 – 0.6 domesticated animals; FC:FS <0.1 wild animals. However, several studies have criticised this approach (e.g. Howell et al., 1995). In particular, sampling needs to be conducted within 24 hours after daefication or manure application since FC and FS die off at different rates; samples ideally need more than 100 FS cfu 100 ml-1; and the receiving water needs to be between pH 4 and 9 because FC die off at a greater rate than FS in acid or alkaline water. Therefore, in practice, this method needs to be used with caution. With the above critique in mind, the FS:FC ratio at Whittle Dene, for samples that fulfil the above criteria, is shown in Figure 4.5 The majority (75%) of samples had FC:FS ratios <4 and all but one outlier of the remaining values were between FC:FS 4 to 5. It is therefore suggested that there are few human sources of FIO discharging to the WDWC and that the majority derive from domestic animals, with an unknown proportion potentially from wild animals.

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Figure 4.5 Faecal Coliform: Faecal Streptococci Ratio at Whittle Dene 2004

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Thus, the project has been able to assess the concentrations of FIO in the WDWC over contrasting seasons, identify the main ‘high risk’ sites and identify the likely animals responsible. This will allow a response to be drafted with a reasonable amount of confidence. 4.4 Nitrate The EC Nitrates Directive 91/676/EEC (CEC, 1991) is aimed at reducing nitrate pollution from agriculture. The objective is to reduce the problem of eutrophication in surface waters and to limit the concentration of nitrate in drinking water from both ground and surface water. The Directive does not itself set mandatory standards but relies on other legislation. The Surface Water Directive, 75/440/EEC, (CEC, 1975) specifies a mandatory limit of 11.3 mg NO3-N L-1 (50 mg NO3 L-1), while the Drinking Water Directive, 80/778/EEC, (CEC1980) sets the same mandatory value for human consumption via water. There is a large volume of review literature on nutrients in watercourses and drainage waters (e.g. Edwards and Withers, 1998; Haygarth and Jarvis, 1999; Goulding, 2000; Withers and Lord, 2002; Macleod and Haygarth, 2003). It is important to continue to research the nutrient dynamics in relation to water quality. The WDWC was designated part of an NVZ in October 2002, with Statutory measures to decrease nitrate losses to water starting in spring 2003. The WDWC has been included as part of the Nitrate Vulnerable Zones (NVZ) monitoring programme and will share water quality and land management data with this project. Historical data on nitrate in the watercourses around Whittle Dene showed the usual seasonal trends, with larger concentrations in autumn and winter (e.g. Davies, 2000). The concentrations of nitrate in spot samples from the Whittle Burn exceeded the 11.3 mg NO3-N L-1 limit routinely in autumn and winter in the 1990s, while the concentrations of nitrate were also large in the River Pont and Coldcoates Burn. As discussed in Section 2.12, the concentrations reported by the EA in autumn are likely to be below the actual peak concentration since these were ‘spot’ samples, taken by hand at a low sampling frequency without consideration of flow conditions. Of particular interest was the reduction in concentrations in nitrate during 2000 – 2002 compared to previous years. There are two potential reasons for this observation; one relating to rainfall and the other foot and mouth disease (FMD). In autumn 2000, September, October and November produced rainfall totals over the country which were unprecedented in modern times (503 mm, averaged over England and Wales, 188% of normal). This is the highest value since records began in 1766, so the return value exceeded once in c. 250 years. The next highest value of 456 mm occurred during 1852 (Shepherd et al., 2001). The heavy rainfall of autumn 2000 leached large amounts of nitrate from the soil but, in turn, this was diluted by the large volumes of runoff and flow in the watercourses. The more rain there is, the smaller the flow-weighted average concentration of nitrate in over-winter drainage. Historically, this is why high nitrate concentrations in waters are found in the drier, eastern half of the country. Thus, the consequences of a wetter than average autumn/winter are two-fold: more N leached from fields (with an impact on subsequent soil N supply to the next crop), but an increased likelihood of a lower flow-weighted N concentration. Fieldwork was delayed, and crop establishment was often deferred to the spring (Shepherd et al., 2001). The small proportion of fieldwork that was carried out effectively reduced the amount of nitrogen that was mineralised in the soil after harvest, since soil disturbance causes increased transformation of organic forms of N to mineral-N as a result of stimulation of mineralising bacteria (Silgram & Shepherd 1999).

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In spring 2001, FMD was diagnosed on a pig fattening unit near Heddon-on the Wall, approximately 6 km east of the catchment. Some three quarters of the farms in Northumberland were placed under some form of restriction; over 300 farms had their stock culled; over 230,000 farm animals were slaughtered (Anon, undated). Restrictions on manure applications and farm movements were also imposed. The drastic reduction in farm animals, and manure applications, are reflected in the low concentrations of nitrate during the successive two years. The data in Figures 3.2 to 3.4 shows a gradual increase in autumn nitrate concentrations in 2002 and 2003, and it is possible that this reflects the gradual re-stocking and return to normality following the 2001 FMD outbreak. The NEAP-N and MAGPIE modelling system predicted nitrate losses as being largest in the south-east of the area, with smallest losses in the north-west (Figure 4.6). This division typically reflects the low input grassland associated with the more undulating terrain in the north of the area. The three largest loss categories represented approximately 37% of the modelled area and the WDWC fell within these values.

Figure 4.6 Predicted loss of nitrate (kg NO3-N) in an average year It is difficult to draw direct comparisons between modelled and measured loads of nitrate in the small WDWC since the modelled values correspond to specific 1 km grid squares which fall both inside and outside the monitored area. The total load of NO3-N from the monitored area of WDWC was 2,228 and 8,291 kg for 2003 and 2004, respectively. As discussed in Section 3.4, 2003 was exceptionally dry (61% of average rainfall), while rainfall during 2004 was 113% of average, but very variable. Figure 3.13 shows the loadings of nitrate-N to the main sampling points across the WDWC. It is particularly important to note that losses of nitrate were minimal in autumn 2003 due the exceptionally dry conditions. Losses of nitrate were large in December, and this continued through spring 2004. This served to effectively ‘shift’ a proportion of the usual autumn nitrate leaching loads into 2004, thereby increasing the total amount lost in 2004 compared to what would be expected in an average year.

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The modelled values for 1 km grid squares that include the WDWC were between 2,500 kg and 3,750 kg for an ‘average’ year. Thus, considering the dry conditions in 2003 and the variable conditions in 2004, the results were considered to be in reasonable agreement if aggregated over the catchment area. It is difficult to draw meaningful conclusions between cropping, fertiliser management and nitrate concentrations in the Whittle Burn. As discussed in Section 3, the unseasonably dry conditions of 2003, compared to the particularly wet summer of 2004 will have greatly influenced the results in both years. It is possible, however, to make some general observations that should be acted upon. Farm surveys indicated that fertiliser planning could be improved across large areas of the catchment. For example, arable fields in the east of the catchment have apparently received annual applications of 225 kg N ha-1 regardless of previous crop, and this is a large amount compared to recommendations given in RB209 (MAFF, 2000). Some other fields in the catchment have significant limitations in terms of drainage and expected yields should be accounted for when planning fertiliser applications. Grass is a permanent crop with a well-developed root system and is therefore able to utilise mineral-N in the soil throughout the growing season. As a result, there is less opportunity for high levels of nitrate to accumulate in autumn than in arable fields, many of which will be bare or have a sparse crop cover at this time. The well-developed root system is also efficient at utilising N added to the soil as fertiliser. Grassland is also cultivated less frequently than land used for arable cropping. Cultivation and the increased risk of leaching will therefore only affect a proportion of the farm in any one year. Greater evapotranspiration during the growing season may result in greater soil moisture deficits than in comparable arable fields and delay the onset of leaching in autumn or winter (Shepherd et al., 2001). These characteristics will tend to reduce the quantities of N leached. Other characteristics of grassland increase the risk of loss. Soils under long-term grassland accumulate higher contents of organic matter than under arable cropping. Total-N contents of topsoils are typically between 5 and 15 t N/ha, compared with 2 to 4 t/ha in arable fields (Whitehead, 1995). There is thus potential for considerable amounts of N to be released by mineralisation of SOM, though the amounts released differ widely. This is well shown on the SMN maps where the grassland fields contained consistently more mineral N than arable fields. However, care must be taken when interpreting SMN data in this way, since N fluxes can be considerable. For example, in terms of sampling, October 2002 was conducted in good conditions; moist soil throughout the soil profile before drainage commenced. However, difficulties were encountered in autumn 2003 and autumn 2004. In autumn 2003, soil conditions were not suitable to auger samples 90 cm deep due to the exceptionally dry weather (Section 3.4) and the soil conditions only became suitable in December. A large factor in the reduction of SMN in autumn 2003 compared to 2002 was the dry conditions. Previous studies have shown that mineralisation of organic forms of N in the soil profile are enhanced by warm, moist conditions and especially after cultivation (e.g. Goss et al., 1993). Thus, the conditions in autumn 2003 were unsuited to mineralisation of organic forms of N, and soil conditions generally were not conducive to cultivation until late in the season. This suggests that soil SMN could be expected to be smaller than previous years. Conversely, summer and autumn 2004 were very wet. Soil conditions were not suitable for augering and farmers were understandably reluctant to allow access until fields dried out. In some cases, the standing crop was still in the field in autumn 2004, again preventing field

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access for soil sampling purposes. As described in Section 3.4 the large amounts of rainfall in August and October 2004 caused large amounts of nitrate to be leached from the soil (See Figure 3.13). It is therefore possible that the soil was sampled after a large proportion of SMN was lost from the soil profile, thus causing an apparent significant reduction compared to previous years. Monitoring in 2002-2004 has therefore been greatly influenced by abnormal rainfall. However, the concentrations of nitrate in winter/ spring 2003 and autumn 2004 exceeded the limit of 11.3 NO3-N L-1 (50.0 mg NO3 L-1). There were large concentrations of mineral N in fields in autumn 2002 compared to 2003 and 2004, indicating that there is considerable scope to reduce inputs of N across the catchment. This was confirmed by assessing fertiliser policy for the farms. It is important to ensure that fertiliser use is matched closely to crop requirement and expected yield and this should be viewed holistically to include factors which adversely affect crop health, such as soil conditions and drainage, for example. 4.5 Phosphorus and sediment Phosphorus is usually the limiting nutrient in freshwater systems (e.g. Withers and Lord, 2002). P is typically mobilised with sediment during storm events (e.g. Edwards and Withers, 1998). There are currently no proscribed limits for P in surface waters, but the guideline value for MRP in freshwater is 100 µg L-1 (EA, 2000). Concentrations above this usually indicate eutrophication, but it is recognised that the relationship between nutrient load, water concentration and trophic state is often site-specific, depending on the type and sensitivity of the watercourse (Foy & Withers, 1995; Edwards et al., 2000). At Whittle Dene, concentrations were generally <50 µg MRP L-1 but exceeded 100 µg L-1 during low flow and storm events. The vegetation assessment found that most of the aquatic species at Whittle Dene were found under eutrophic (high nutrient) conditions. Only Glyceria fluitans, which is described as mainly mesotrophic, is the exception. None of the species would be found in only oligotrophic (low nutrient) conditions however. This assessment supports the findings of the water quality monitoring survey and the modelling results, it also supports observations of algal blooms in the reservoir network. Conversely, the surveys of aquatic invertebrates revealed that there was a rich community of aquatic macro-invertebrates in the Whittle Burn, contributing to the aquatic biodiversity of the Whittle Dene catchment. Some 17 of 41 families were present with BMWP scores ≥ 6 indicating water of relatively good quality. However, biotic indices were initially developed for considering organic pollution such as sewage and not agrochemical impacts. Additionally, the survey was conducted during the dry summer of 2003 and, therefore, results may not show the normal invertebrate community inhabiting the Whittle Burn. It is recommended that surveys are repeated in order to more fully assess the aquatic community of the Burn. Of all forms of phosphorus, most will be found in the total fraction, associated with suspended sediments and mobilised primarily during rainfall (e.g. Macleod and Haygarth, 2003). Soil erosion and overland flow are recognised as the most significant transport mechanisms, and have been exacerbated as a consequence of changes in cultivation, cropping practices and the intensification of livestock systems (Withers et al., 1998). The concentrations of TP and sediment at F2 were especially large during the high flow of August 2004. This site is largely surrounded by dense vegetation in a large channel, so the sediment concerned is likely to have been partly transported directly from upstream (e.g. where livestock access the burn; poor drainage causing overland flow in arable fields well connected to the burn), and partly from re-mobilised stream bed sediment.

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The data on water quality were sorted by season and by flow conditions at time of sampling in order to more fully understand and describe the characteristics that are responsible for driving particulate movement in the Whittle Burn. Figure 4.7 shows regression of flow vs concentrations of TP at monitoring point F2. There is an apparent large increase in concentration of TP in the Burn at flow >10,000 m3 day-1, but as can be seen, this is almost entirely accounted for by summer storms in 2004, which caused peak flow >1.2 cumecs in the Whittle Burn.

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Figure 4.7 Concentration of TP (µg L-1) vs total daily flow (m3 day-1) Increased rainfall, and in particular, rainfall intensity, is important in stimulating transport processes such as runoff from fields or drainflow. However, diffuse pollution can also be source-limited, where transport conditions exist, but sources of the substance are exhausted or not available. This will be true of all potential pollutants, but availability may vary throughout the year depending on a range of land management factors. For example, bare soil will tend to exacerbate soil erosion on steep slopes in winter, but vegetated slopes will tend to reduce the source (soil particle detachment) and transport (movement downslope) by binding the soil particles and increasing infiltration. Analyses of topsoil in spring 2003 showed that concentrations of Olsen extractable P were not large in relation to values in England and Wales. At Whittle Dene, 84% of fields contained <26 mg Olsen-P L-1, whereas Harrod and Fraser, (1999) reported median values of 26 mg kg-1 and 17 mg kg-1 Oslen-P for arable and long-term grassland, respectively, for England and Wales. Larger concentrations were found in individual grassland fields that were close to livestock holdings and this is likely to reflect factors such as ease of manure application, increased livestock movements or increased livestock grazing close to the holding. The guideline value of 25 mg L-1 for suspended sediment under the Freshwater Fish Directive (78/659/EEC) was exceeded in the main burn for much of the year. The concentrations of suspended sediment in streamflow are directly related to velocity and available substrate for suspension. Sediment may be re-suspended from the stream-bed, or

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derived directly from soil erosion during rainfall. The peak was >500 mg l-1 during summer storms of 2004. The large concentrations during the summer storms of 2004 are likely to have resulted from sediment from several sources, and these are discussed further in the following paragraphs. One field in the south of the WDWC is of particular interest with regards to losses of P and sediment. The soil in this field has 26 mg Olsen-P L-1, which is at the lower boundary of P Index 3. It adjoins the Whittle Burn, is unfenced and is used to graze livestock. Cattle can be seen to be watering directly from the Burn with the usual problems of direct daefication to the water, puddling the stream bed and banks. In high flow, there will be unconsolidated bed sediment and other material that will become suspended and entrained in the current. There are reports that the Whittle Burn has become silted and ‘choked’ in recent years. This has coincided with both an increased arable area and the felling of a small block of woodland (with associated bare soil). Woodland and forestry operations can be a significant source of sediment to watercourses (e.g. Stott and Mount, 2004) and there are many small blocks of woodland in the area around Whittle Dene, (approximately 4.2% of land cover in 340 km2). Just as agriculture has Codes of Good Practice for protection of Soils, Water and Air, there are Forest and Water Guidelines (Forestry Commission, 2003). These guidelines should minimise water quality problems as a result of forestry operations, and it will be important to work with managers of small blocks of commercial woodland, such as that found in the WDWC. Other sources of sediment and particulate-P in the WDWC include runoff from poorly drained fields, sediment from arable field drains, trackways which slope to the Burn, farm hardstandings, and, potentially, runoff from roads and verges via drains. The issue of sediment from roads has not been well studied. One exception is the Leadon study, which has focused on the role of metalled and unmetalled roads in the delivery of sediment from fields to rivers. The Leadon has a high annual suspended sediment yield (>350 t km-2 yr-1) and preliminary results suggest that c. 30% of this sediment has been delivered to the river via this pathway. Results from this investigation are being used by the EA and FWAG in the development of a fine sediment management strategy for the Leadon (Foster, 2005). The Western Catchment includes a main field drain which is apparently partly fed by road runoff. Thus, the drain flows at significant rates after intense storms. Traditionally, field drains are not assumed to run during a typical summer apart from selected occasions when macropore flow from cracking soil types moves directly to the drain. Indications are that pesticide residue contained inside the drain may be mobilised by the intense road runoff. This will be influenced by degradation times of substances within the drain system. Little research has been conducted into this, and it is not known if this transport pathway has been documented. Further, it is unknown if such a situation is widespread. For example, consultancy work in a similar environment revealed a similar situation where road drainage and field drainage could be considered to be a single system. In common with other catchments, there are several potential sources of sediment and particulate-P. Monitoring has revealed relatively large concentrations across the catchment during key transport events. It was desirable to establish how widespread soil erosion is in the area and a model was used to indicate this. The Morgan-Morgan-Finney model (Morgan, 2001) for predicting annual soil loss by water is considered to be a useful erosion screening tool for such a situation. Figure 4.8 shows the predicted soil erosion risk for an area around Whittle Dene. The ‘high risk’ areas are generally to the north and east of the modelled area, coinciding with steep slopes of the Rivers Tyne and North Tyne valleys, and those of the Erring Burn. The relatively gentle slopes of the WDWC area are shown as being ‘low risk’ of soil erosion, yet

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there are relatively large concentrations of sediment in the burn. This illustrates the risk of using models as screening tools; there are land management factors that are difficult to account for. At Whittle Dene, field drainage, forestry and animal management have combined causing increased sediment in the burn than might be expected, especially during high-flow. Only detailed monitoring and field investigations have revealed, local, but important, issues. This should be borne in mind when conducting catchment characterisations.

Figure 4.8 Risk of soil erosion by water in an average year around Whittle Dene It is important to discuss pressures that will have an impact on water quality. Soil management is a particularly important issue that impacts on water quality generally and this is discussed further below. 4.6 Soils and drainage Soils have a major physical influence on hydrological processes. Their physical properties govern the storage and transmission of water within the soil, and these properties combine with other characteristics to act as chemical buffers and biological filters to a greater or lesser extent. Though some of these effects can be observed at a very small scale, their influence can become pronounced when aggregated across the whole of the catchment. A significant area within this catchment is managed using minimum tillage methods. Where this is carried out under good conditions it can improve topsoil structure (Harris and Catt, 1999) but minimum tillage can also induce the perched water table zone to be created closer to the surface, and increase runoff (Harris et al., 1993). The efficiency of old field drainage systems might be improved in some circumstances by selective subsoiling within a rotation. This increases the water holding capacity of the soil profile and would tend to increase the lag time between rainfall event and lateral drainage

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through the soil occurring. This may have important implications in terms of pesticide losses from the soil system. However, these soils are texturally unsuited to mole drainage due to variability in texture across fields which can cause mole drainage to collapse prematurely. Fine textures and moderate or poor structure of the dominant soil in the catchment, Brickfield, results in slowly permeable subsoil that may remain waterlogged for extended periods. The high number of days at field capacity, (mean 177; Jarvis et al., 1984), makes spring cropping a significant risk, however these soils are moderately productive for grassland and winter cropping. Winter use by livestock, and particularly cattle, would risk severe poaching in wet years. Productive agricultural use would not be feasible without piped underdrainage, although many of the systems present within the catchment are be very old (c. 19C). The high groundwater level within the Enborne Association soil area, will result in drainage being predominantly lateral. It should be noted that soils with a high fine sand or silt content tend to be particularly unstable when uncropped, resulting in accelerated surface run-off due to capping of the surface layer. This can result in localised gullying and loss of topsoil/ sediment into the watercourse. The Rivington series soils are freely draining and are unlikely to be waterlogged in all but the most extreme rainfall events. Drainage will normally be vertical and very rapid to the bedrock. Any chemicals disposed of by tipping onto the land such as sheep dip washings etc. will move very rapidly into watercourse on this type of land. With the exception of the field south of Vallum Farm which may have been disturbed, topsoil structural condition was good at the time of sampling under ploughed land and minimum tilled. There was no evidence of smearing or compaction in the min till soils and relatively minor compaction evident at the plough layer base in ploughed fields. This is at least in part due to the extended dry spell in late summer and autumn 2003, giving near ideal conditions for cultivation and seedbed preparation. Similarly, the dry autumn and low cattle numbers has meant that poaching was virtually non existent in 2003. The exceptions were two fields in the south west corner of the study area, where grazing cattle have caused localised severe poaching around feeding areas. There were some grassland areas adjacent to the B6318, which are waterlogged, and would be very vulnerable to poaching if they were to be grazed over the winter period. These were also identified as ‘high risk’ source areas for faecal material to watercourses. Like most parts of England and Wales, general agricultural intensification has taken place in Northumberland over the last 200 years. There is a long history of in-field drainage designed to increase the economic productivity of the land, whether for crops or livestock. In particular there has been significant amounts of post-Second World War drainage, which was grant aided by MAFF until the early 1980’s. Many landowners took advantage of these grants to convert historic extensive grassland into more intensive arable systems. In addition, many open farm ditches were filled in and replaced by piped ditches to increase productive arable field areas. Agricultural land drainage and its maintenance will have a profound impact on how quickly rainfall falling on the land reaches watercourses and what pollutants, if any, this water moves with it, either in solution or adsorbed to soil particles. The general lack of permeable fill in the drainage trenches, together with an absence of secondary treatments, will have the effect over time of decreasing the overall drainage effectiveness. Without good connectivity to the in-field drainage pipes at 1m depth in the profile the soil water will not percolate through soil effectively. More water will tend to remain either on or within the shallow plough layer, especially if it is at all smeared at its base following cultivations. Overland and near surface flow would become the dominant flow

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paths and pollutants will be transported with the water moving along these paths. There were few indications of remedial work being conducted on field drainage systems during the course of this study but the dry autumn soil was in an ideal condition to use a subsoiler to reduce subsurface compaction, and many farmers appeared to use this opportunity. On the fields dominated by the Brickfield association, surface flow or run-off is very unlikely except under the severest of rainfall events. However at Whittle Dene, in the absence of gravel fill over the field drains, there is seasonal waterlogging occurring at the topsoil/subsoil boundary or just below, where the soil becomes slowly permeable. It is probable that this will lead to lateral drainage across this layer and because it is relatively close to the surface it will mean that there is a very short lag time between rainfall incidents and drainage flow, as demonstrated by the hydrograph peaks, especially in the wet months of 2004. The effectiveness of drainage systems relies not only on the in-field soil conditions and pipe condition, but also on effective drainage outfalls to allow sufficient headfall. Visual examination of the ditches within the WDWC showed that in places there is an urgent need for maintenance and clearance. Towards the head of the catchment the Whittle Burn is nearly completely silted up, and drainage outfalls are often below the apparent bed of the burn. This has made in-field drainage completely ineffectual in places, causing increased soil erosion from arable fields (Plate 4.1). Other mechanisms include the blocking of drains and outfalls by roots, especially bankside trees such as Willow (Plate 4.2). This feedback loop should not be allowed to continue and can be addressed relatively easily.

Plate 4.1 (left) Soil erosion and poor drainage at Whittle Dene Plate 4.2 (below) Field drain blocked by Willow roots (photo from outside catchment)

In the UK, the greatest flood risk is normally from clay-based soils that have been traditionally underdrained and, where used to support arable crops, the drainage will include a comprehensive drainage system of permanent pipe drainage and a secondary drainage treatment (mole drainage or subsoiling). Both mole drainage and subsoiling act within the soil profile to provide an additional drainage function and means to remove excess rainfall in these largely impermeable soils.

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Recent trends in drainage reported by Harris & Pepper (1999) have indicated substantial changes in the status of UK drainage of clay soils following the changes in grant-aid in the mid-1980s. Harris & Pepper (1999) reported that very few new permanent underdrainage pipe systems were being installed with reliance increasingly on old systems (typically 30-50 years old) that were likely to be showing signs of mis-alignment of clay tiles, blockage of plastic pipe perforations and general siltation. Harris & Pepper (1999) considered that the gradual deterioration of drainage pipe outfalls, due to loss of headwall and siltation of ditch systems, would also affect drainage status. In addition, farmers/landowners were increasingly undertaking the maintenance of secondary drainage systems, with a trend towards longer time intervals between renewal, shallow depths and more subsoiling (‘recreational subsoiling’) over less well maintained mole drainage systems. In most seasons, this gradual, almost unnoticeable, deterioration of the complete drainage system would not be apparent in the wider countryside, although the original function of the drainage (e.g. moling designed to remove excess rainfall within 24 h) would increasingly not be met. The effect on watertable control of less efficient drainage in clay soils was reported by Harris et al. (1993). It resulted in observable mean differences over the winter period, with a mean watertable depth of 457 mm reducing to 204 mm without drainage at the research site at Brimstone Farm (1978-88) for a heavy drained clay and ploughed soil. The effect of reducing the standard of drainage, as a result of less maintenance would fall part way between that of a drained soil and that representing the undrained state. Other modern cultivation systems which do not include inversion of the soil (e.g. minimal tillage, direct drilling) are likely to result in a higher proportion of surface run-off occurring (Harris & Catt, 1999), with the mean depth of the watertable reduced from 407 mm to 229 mm over the same period reported above (Harris et al., 1993). Under less effective drainage conditions, there will be a tendency in all winters to return to field capacity earlier, resulting in potentially more difficult soil management conditions and increased difficulties for the application of autumn pesticides and early spring fertilisers. ‘Windows of opportunity’ are likely to be reduced, so that in the undrained soils, such as those observed at Brimstone Farm, the lack of any drainage, accompanied by moderately enhanced autumn rainfalls, was observed to lead to seasons with no potential for crop establishment at all (Harris & Catt, 1999). Under these conditions, it should be borne in mind that current farm economics might encourage practices that lead to damage to the soil profile. Clay soils are extensive, and provide some 45% of the arable land in the England & Wales (Cannell et al., 1978). Their drainage status is therefore of considerable importance to the growth of winter cereals over quite large areas of the rural landscape. However, whilst poor watertable control and an early return to field capacity, can be an important consideration for both trafficability and crop establishment, the effect of subsequent rainfall on flood run-off potential is of equal importance. Harris et al. (2000) concluded that effective drainage of clay soils reduced the risk of flood run-off due to increases in water storage and consequent reductions in surface run-off. Their research, based on ten years of monitoring, showed that a flood flow of 5 L s-1 from undrained ploughed soils would be reduced to around 4 L s-1 by the adoption of effective drainage practices. Research over twenty years showed that a change in drainage status and land management could be considerable, resulting in the 100 year flood on drained ploughed soils being produced every 25 years with no drainage and minimal cultivation. This research has particular relevance at Whittle Dene, where the Brickfield soil series has been shown to produce particularly pronounced hydrograph peaks making the watercourses very responsive to rainfall. Harris et al. (2000) reported a number of factors that are likely to have contributed, to a greater or lesser extent, to the changed run-off patterns within the rural landscape at the catchment scale:

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• Underdrainage status – reduced effectiveness; • Ditch maintenance – see below; • Larger fields and removal of hedge boundaries - which act to retain, at least temporarily,

surface run-off; • Piping of ditches – giving faster run-off; • Loss of ridge and furrows in areas converted from grassland to arable – which

previously provided temporary storage for surface run-off; • Infilling of ponds – which act as temporary storage areas for run-off in the autumn; • Use of permanent tramlines in arable areas – the effect depends on the direction of the

tramline in relation to the slope, but the compaction caused by permanent tramlines can increase the speed of run-off and substantially increase the consequent flood risk.

Research has shown that most of these factors are fulfilled at Whittle Dene. The effect of a lower standard of ditch maintenance can be complex. Whereas poor ditch maintenance may cause local flood spots, in general, rougher ditch profiles can temporarily pond back flood run-off. In contrast, infilling of ditches by sediment will reduce overall storage capacity, and there are locations where sediment levels in the ditches has caused outfall drains to completely fail, exacerbating the deterioration of in-field pipes and causing in-field waterlogging. To reduce the risk of long-term flooding problems, particularly if climate change leads to heavier autumn/winter rainfall and more intense rainfall, as predicted under the medium-high UKCIP scenario (Hulme & Jenkins, 1998), a return to agricultural systems that reduce the risk of rapid surface run-off generation and transmission to rivers is needed. Maintaining a high standard of drainage and the use of cultivation systems that maximise soil storage are to be preferred, as well as cropping systems that minimise bare or compacted soil in the autumn. Introducing temporary storage areas as provided by ponds, hedges and deeper ditches with storage sumps, would all contribute to reducing flood generation. Balanced against this, there is uncertainty as to the effect of underdrainage on the magnitude of diffuse pollution. For example, at Brimstone Farm (Denchworth Series) restricting drainage effectiveness by adding an inverted U-bend to the drainage outfall achieved the effect of holding water in the soil profile for longer, while still permitting drainage under high-rainfall conditions, and this reduced losses of isoproturon by up to 25%. Widening of mole-drain spacings, examined as a practical interpretation of the U-bend restrictive-drainage approach, did not however reduce pesticide loss (e.g. Jones et al., 2000). Conversely, Brown et al. (1995) conducted studies at Cockle Park, Northumberland, on a Dunkeswick Series soil and found that total losses of autumn applied pesticides were up to four times greater from an undrained plot, compared to a plot with effective mole drainage. This was ascribed to the infiltration of the pesticide through the soil of the drained plots which provided an element of natural filtration compared to surface layer flow. It should be noted that the Brickfield soils at Whittle Dene, have very similar characteristics as Dunkeswick soils, and therefore this research holds particular relevance. Consideration should be given to the fact that high concentrations of IPU and other soluble, mobile pesticides from agricultural land can be generated by a wide variation in both rainfall and antecedent conditions. For example, rainfall intensity rather than total quantity can generate significant volumes of runoff and this in turn can be strongly influenced by soil conditions, especially the soil infiltration capacity. Thus, intense rainfall on saturated soils may be susceptible to runoff, but conversely, dry, baked soils can also have a low infiltration capacity which can also cause significant runoff (and potentially soil erosion) during summer months. Long periods of low intensity rainfall can also generate runoff. Subsurface flow and

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drainflow are likely to be significant in the autumn and winter when the pore-spaces between soil particles are full of water (i.e. at Field Capacity), and any further rain will cause drainflow. However, soil structure and physical conditions at the time of rainfall will also influence the amount of runoff, subsurface flow and drainflow and it has been shown that dry, cracked soils can cause rainfall to be rapidly routed to the sub-surface drains long before the soil profile wets sufficiently to allow drains to flow ‘naturally’. This by-passing of the soil matrix can potentially carry contaminants to drains rapidly from the topsoil. Based on the proceeding paragraphs, there are potentially two farm management options to reduce runoff from wetness limited, low grade land at Whittle Dene. It would be possible to conduct remedial actions on high-risk fields. This would improve crop health, which would in principle improve uptake of nutrients and reduce disease risk, for example. Yields would be improved and the improved utilisation of nutrients may reduce losses, while potentially there would be a reduced need for some pesticides. Alternatively, the utilisation of low-grade land for arable cropping may be considered a poor use. Where grants are available, e.g. under ELS, it may be preferable to consider arable reversion to grassland; preferably low-input grassland with extensive beef and sheep in this locality. The intensification of agricultural production, where fewer people manage larger areas of land producing increasingly higher crop yields is clearly evident in the catchment. Farmers remarked that this intensification, forced on them by market pressures is primarily responsible for the diffuse pollution from residual pesticides. They accepted it as a consequence of intense agriculture. However, it is easy to see the problems that can be caused. As farmers leave the industry, neighbours continued to farm the land, or landlords take the land back in hand and farm it themselves. Thus, the holding is increased in size, requiring a change in management. This is reflected in the field drainage records and change in management practices; i.e. the trend towards large pieces of machinery and contractors. These are used to work large areas of land with little flexibility and there is a strong pressure to use machinery or apply pesticides at unsuitable times. Both of these can translate into increase risk from pesticide losses by damaging soil structure and increasing the risk of runoff, and by applying pesticide products prior to known rainfall or to excessively wet soils, for example. Amalgamation of enterprises to spread capital costs over a larger area has become a feature of agriculture in the UK over the past ten years. Rented land is sometimes passed to the landlord to farm in hand, and smaller farms may sell land, or cease farming. Increasingly, farms find it more profitable to work large fields than smaller ones. The four main holdings in the catchment, from west to east comprise a mixed farm with sheep, beef and a small block of arable (rented); a mixed beef and arable farm (owner-occupied); a newly retired mixed farm which lets land on short-term tenancy; and a dedicated arable farm (rented). In common with many regions, there is an increasing reliance on contractors and short-term tenancies. The farmer will typically have little control on contractors, who may be pressured to work the land in unsuitable conditions, while farmers may have no knowledge of the practical limitations and physical characteristics of rented land and may therefore face difficult management decisions with regards to soil conditions. Options under single farm payment (SFP), will break the link between production and support. Instead, farmers will be asked to demonstrate that they are complying with a number of specified legal and advisory requirements relating to the environment, public and plant health, animal health and welfare, and livestock identification and tracing, known as Cross Compliance (XC). This, in conjunction with new agri-environmental schemes, may help to focus attention on subtle management changes which may improve water and environmental quality. A response to the water quality issues raised in this section is formulated as a catchment plan in Section 5.

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5. CATCHMENT PLAN 5.1 Catchment planning for agriculture and water quality Section 4 described the water quality issues in the WDWC and surrounding environs, before describing the investigations that were conducted to identify the many causes. The investigations were conducted at three scales;

• The wider catchment (c. 500 km2), incorporating existing water quality data, land use, land cover, soil type, and screening models for diffuse pollution risk.

• The Whittle Dene Western Catchment (WDWC) (3.9 km2) detailed monitoring and investigations to identify the sources and transport of diffuse pollutants and their causes.

• Individual fields assessed for soil nutrients and physical condition, drainage, field management, animal husbandry.

Resources for catchment management of diffuse pollution are likely to dictate that detailed investigations are limited to specific, problematic areas. Phase I has shown how intensive investigations can successfully identify the sources and causes of water quality issues in small catchments, but this is clearly not practical without a method for identifying these areas. Models and local knowledge were used to indicate the situation in the environs around Whittle Dene, and such information is useful to target specific areas for study. Models were useful for screening large areas, but Phase I also showed that the issues responsible were often beyond the designed capabilities of the software. For example, underdrainage maintenance, or livestock watering from the Burn had a large effect on several water quality parameters, but this level of detail is generally not possible to include in modelling. The results show that models are useful in guiding attention, but there is still a considerable amount of investigative work required before solutions can be tailored to the locality. The project has clearly shown that water quality is insufficiently studied at the small catchment scale where factors beyond strict scientific principles on losses of nutrients, FIO’s or pesticide substances from agricultural systems come into play. Farm management, diversification, economics, domestic dwellings, historical land drainage, and catchment physical characteristics are all complicating factors. By undertaking detailed studies, the project is now in an excellent position to put forward a response in the form of a catchment plan. At the outset, it was considered essential that any proposed response must be relevant to current (and projected) agricultural policy. This has continued apace since the project inception in autumn 2002. There have been several reviews on water quality (e.g. Defra 2002a & b; Defra 2004a) together with a response, in the form of Catchment Sensitive Farming (CSF) (Defra, 2004b). In addition, the review of the Common Agricultural Policy will have a large impact on agriculture and water quality and this was researched by Silcock et al. (2004). It is beyond the scope of this Section to discuss these reports in detail, but key points will be outlined where they are relevant to the proposed future work at Whittle Dene. It is proposed to continue to monitor the WDWC during and after the introduction of the SFP and the land management that it requires under Cross Compliance (XC). In addition, it is intended to make best use of the new Environmental Stewardship schemes to improve water

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quality. However, it is acknowledged that some additional action may be desirable at Whittle Dene in order to address some specific problems, therefore some additional work and capital schemes are also proposed. All these options are to be put forward as a plan to improve the water quality at Whittle Dene. It is anticipated that, after the plan is introduced, the WDWC can be used as a ‘demonstration catchment’ for agriculture and the water environment and that scientists, policymakers and practitioners will be able to make use of it. Research has shown that the primary water quality issues in the WDWC relate to agriculture and, potentially, forestry. This section will:

1. Examine changes to agricultural policy that will affect farm businesses, land management and environmental provision

2. Outline characteristics of agriculture in the NE region; explore how farms in the WDWC

3. Devise best plan for the WDWC based on findings from the catchment characterisation, and the specific problems that have been identified and characterised in detail (Section 4).

4. Outline the agreed research approaches. 5.2 CAP reform The mid-term review of the CAP will bring radical change to farm support by completely decoupling subsidies and production in England. Key elements of the agreed reform are:

• A single farm payment (SFP), relating to the area farmed and independent of production (decoupling). The level of this area payment will vary according to land type, with 3 categories of farmland; Moorland, Severely Disadvantaged Area (SDA) and non-SDA.

• Cross compliance for respecting elements of the environment, food quality and safety, animal health and welfare and occupational safety

• A stronger rural development policy with more funding for Pillar II of the CAP. This will be funded through modulation (reduction) of Pillar I payments

• A reduction in direct payments (digression) to larger farms The flat rate single farm payment will comprise two elements; a Regional Area Payment (RAP), which will be phased in over a period of 8 years and an element of historic support, which will be phased out (Table 5.1). The historic element will be based on average subsidy claims made in the reference period (2000, 2001 and 2002) and will to some extent act as a buffer for farm businesses to adjust to the new circumstances. Table 5.1 Transition to Flat Rate Payments 2005-2012 2005 2006 2007 2008 2009 2010 2011 2012 Historic Rate* 90% 85% 70% 55% 40% 25% 10% 0% RAP Rate** 10% 15% 30% 45% 60% 75% 90% 100% * as a proportion of 2000-2002 payment levels ** as a proportion of the final level There will be three regions with varying RAP rates. Defra estimate the following rates (before National reserve allocation and modulation):

A £20 to £40 per hectare in the SDA Moorland B £110 to £130 per hectare in the rest of the SDA C £210 to £230 per hectare elsewhere

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This will give rise to some anomalies in distribution impacts where these boundaries are drawn. There will also be competition implication along the Scottish border as the Scottish Assembly have opted for a hybrid model with an ongoing historic element and coupled payments for beef. This is not relevant for the area around Whittle Dene. The new scheme will break the link between production and support. Instead, farmers will be asked to demonstrate that they are complying with a number of specified legal and advisory requirements relating to the environment, public and plant health, animal health and welfare, and livestock identification and tracing, known as Cross Compliance (XC). Cross compliance (XC) is divided into sets of requirements, all of which farmers must meet in order to receive the SFP and other direct payments in full. These include maintenance of land in Good Agricultural and Environmental Condition (GAEC), (including a phased introduction of soil management) and Statutory Management Requirements (SMRs). SMR’s are domestic provisions derived from EC directives. In addition, member states are required to maintain the area of permanent grassland on a national basis. Several agri-environmental and other land management schemes are already in existence. If there are any conflicts between the requirements of these schemes and those of XC, the requirement of the agri-environmental scheme will take precedence. The full details of the Single Payment Scheme and Cross Compliance, together with a list of the GAEC and SMR’s, can be found in Defra (2005a,b). The GAEC requirements for soils are detailed in Defra (2005b). The intention is for all farmers to draft a risk-based soil management plan for introduction from 2007 onwards. There are therefore two years for familiarisation of the guidelines and drafting of the plan, prior to implementation. The guidelines for ‘heavy soils’ are particularly relevant to the area around Whittle Dene. Amongst the principles of good soil husbandry for heavy soils are those for effective underdrainage systems and regular maintenance of field drains and ditches. These aspects need especial attention at Whittle Dene. Similarly, for forestry, the Environmental Impact Assessment (Forestry) Regulations, 1999, apply to afforestation, deforestation and forest road works. All work must be subject to a consent by the Forestry Commission. 5.3 ELS and HLS At the same time as the introduction of the SFP, the current agri-environmental schemes are being revised. These are separate exercises, but will be introduced approximately at the same time from 2005 onwards. There will be three elements:

• Entry Level Stewardship (ELS) • Organic Entry Level Stewardship (OELS) • Higher Level Stewardship (HLS)

Agri-Environment payments are completely separate from SPS payments and are paid to farmers and land managers who voluntarily join Defra Agri-Environment schemes including Countryside Stewardship (CSS), Organic Farming Scheme (OFS), Environmentally Sensitive Areas (ESA) and the three elements of Environmental Stewardship that will replace them. These payments are not subsidy entitlements but are made in return for carrying out environmentally beneficial land management. Agri-Environment payments are therefore not part of the SPS.

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The new agri-environment scheme Environmental Stewardship will be launched in early 2005. It will replace the existing schemes including CSS, ESA, OFS and some Wildlife Enhancement Scheme agreements. It has three components, one of which is the Entry Level Scheme (ELS). The others are OELS – Organic Entry Level Stewardship (available to those wishing to farm organically) and Higher Level Stewardship (HLS) for those able and wanting to deliver higher levels of environmental management and enhancement. ELS is available to all farmers and other land managers and entry is guaranteed providing scheme requirements are met. Applicants choose certain environmental commitments (each of which earns points) to attain a points threshold. Farmers and land managers will choose from over 50 management options to reach a points target related to the size of the farm. These options will include the protection and management of boundary features, woodland edge, soils and historic and landscape features. It is designed to be a simple scheme requiring little expert knowledge over that held by a competent farmer and is intended to secure a basic level of environmental management. ELS agreements will have a flat rate payment of £30 per hectare across the whole farm. OELS payments will be £60 per hectare for organic land (and £30 per hectare for conventional land) recognising the additional environmental benefits accruing from organic farming. The management options selected by a farmer will complement the obligations arising from cross compliance. Entering into ELS or OELS will not remove the cross compliance obligations. Higher Level Stewardship (HLS) aims to deliver significant environmental benefits in specific high priority situations and areas. The scheme will concentrate on the more complex types of management where land managers need advice and support and where agreements need tailoring to local circumstances. In almost every case an HLS agreement will also include ELS or OELS options. 5.4 Farming in the North East The North East has a distinct agricultural base, reflecting the geography of the area. Key elements include:

Reliance on livestock rearing. Upland livestock rearing is the dominant farm type accounting for nearly 30% of farms compared with just 7% in England as a whole. A further 13% or so are livestock rearing but from a lowland perspective, compared to 21% in England as a whole. Significant arable sector. The other major farming type is combinable crops: cereals (80% of cropped area) and other combinable crops (oil seed rape – 15% of cropped area). Some 19% of farms fall into this category compared to the English average of about 15%. 973 cereal holdings (1570 including mixed) producing 1 million tonnes of grain. Market focused on grain trading. Low incidence of dairying. Only 12% or so of farms rely on milk production.

The agriculture in the Whittle Dene area, and the WDWC specifically, reflects this situation. Thus, any proposed ‘plan’ for water quality in the WDWC will be relevant to a large area in terms of physical characteristics (described in Section 3) and holding characteristics. The effect of measures in the North East will be significant in view of the reliance of the livestock sector on headage payment in the past and the tiers of SFP for hill and upland areas.

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The impact of decoupling on the main sectors has been researched by Defra (e.g. GFA-RACE, 2004) in order to anticipate differential effects. In broad terms, there will be a redistribution of subsidy from more intensive enterprises (intensive beef, dairying, cereals) to less intensive systems (extensive beef and sheep) and negative list enterprises (potatoes, sugar beet, horticulture, outdoor pigs). The change in subsidy by robust farm type is summarised in Figure 5.1.

-15% -10% -5% 0% 5% 10% 15% 20%

Cattle & Sheep (LFA)

Cattle & Sheep(Lowland)

Dairy

Mixed

Cereals

Pigs and Poultry

General Cropping

2005 2006 2007 2008 2009 2010 2011 2012

Figure 5.1 Proportionate Change in Total Subsidy Receipts by Farm Type In terms of redistribution of farm subsidy by farm size Hall et al. (2002) suggests a positive impact for LFA cattle and sheep farms in terms of total subsidy receipts (+15%). For the beef and sheep industry, there is likely to be an overall fall in national beef and sheep production in response to the loss of headage payments and a smaller dairy industry. This may generate a better market balance for farmers and help maintain or improve livestock prices. This should temper the response of individual farmers in terms of reducing livestock numbers. An overall shift in beef production from upland to lowland areas is likely. For the arable sector, payments will remain as before but there will be no requirement to grow the combinable crops. Total subsidy to cereal farms will reduce by 5% while general cropping farms (growing potatoes, sugar beet etc.) will gain by 18% according to the Defra analysis. Much will depend on individual farm cropping. The de-coupling of arable area aid payments from 2005 should encourage a greater diversity of cropping but commercial pressures may lead to greater specialisation. Some marginal arable land may return to grassland. There will still be a requirement to set land aside (all non-permanent crops except continuous grassland) and this will limit market supply. The dairy sector is particularly hard hit by the reforms as subsidy will reduce by 9%, relative to the absence of reform (assumes Dairy Premium was paid). While this is not likely to be significant in overall terms, given the limited scale of dairying in the North East, the danger is that a further loss of producers could mean a loss of critical mass and withdrawal of processing capacity from the region. Concentration of processing capacity within the milk sector means that processing might be restricted to meeting the demand for liquid milk from the conurbations around Teeside.

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These factors are likely to lead to a decrease in the area in traditional cropping. It may also lead to reductions in the labour force. Farmers may also be inclined to try more novel crops (ADAS 2003). Defra research (GFA-RACE, 2004) indicated that decoupling will be generally beneficial for the environment. This relies on reduced production of food and consequently lower input usage. However, a greater market focus could see greater specialisation, both by individual farmers and within geographic areas. This could have negative environmental impacts e.g. more dairying in the South West. For extensive upland systems, the threat is that a reduction in stock numbers (or change in balance from cattle to sheep) might lead to deterioration of habitats and biodiversity. Based on the foregoing analysis, it is apparent that beef and sheep production is likely to remain dominant in the area after introduction of the SFP. However, as described in Section 3, the majority of land around Whittle Dene is unsuited to production of non-combinable crops such as potatoes, sugar beet, or field vegetables and, therefore, the arable land around Whittle Dene is considered likely to remain under typical combinable rotations. The potential for marginal arable land to be reverted to permanent grassland would be positive at several locations at Whittle Dene, especially those fields with poor drainage. If this reversion were coupled with low stocking densities associated with extensive beef and sheep production, then this would minimise the risk of soil structural problems that might be caused by overstocking in wet conditions. If best practice were followed, it is considered that the risk of diffuse pollution could be considerably reduced compared to best practice on marginal arable land close to a watercourse. 5.5 Characteristics of holdings in the WDWC There are three distinct farm types in the Western Catchment, with four other landowners with fields in the catchment, but holdings outside. Each of the farms in the catchment has typical characteristics of the area. The east of the catchment, is dominated by an arable farm and the tenants have indicated that production will be their main objective during and after CAP reform, they are, however, very receptive to the project. The land in the catchment is rented on a short tenancy. There is a beef and arable farm in the north of the catchment, and response is likely to include diversification. The owner also runs a dairy farm outside the catchment. The farm is on Hadrians Wall which was made a National Trail in 2002, and the owner may take advantage of the farms location. The outbuildings have been converted and are let for commercial uses. It is important to be aware of the potential increased contribution of septic system and this should be studied given the likely increase in alternative farm enterprises nationally. The extreme west of the catchment is largely run as a mixed farm. There is a block of marginal arable land that is characterised by long, shallow slopes and poor drainage, both of which contribute to runoff. There are sheep and beef cattle on the farm which are primarily grazed on the steep land to the west. This land has great potential under CAP reform, especially regards to extensive grazing and arable reversion. There is additional land area worked by farms outside the catchment, the farms are co-operative with the project and this land will also be included in the catchment plan. Therefore, the range of holdings lends themselves very well to a diverse study on a representative cross section of local farms.

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5.6 Multiple options presented as a catchment plan 2005 - 2007 The proposal here is to implement the catchment plan in year one (2005), with associated monitoring continuing for three years (Jan 2005 – Dec 2007) i.e. year one: implementation and monitoring; years two and three: continued monitoring and review of effectiveness. 5.6.1 WDWC and cross compliance It is inevitable that a major revision of how rules and guidelines are presented will reveal deficiencies across the country. These are likely to be specific to the locality concerned and will reflect farm type, cropping or land use, or regional differences in farm and land management. Statutory measures, such as the components of GAEC will need to be implemented by every farm under cross-compliance. It is proposed to provide guidance and advice to help farmers in the catchment, and to ensure that options such as soil management plans are used to their full potential. The provision of such advice is likely to be nationwide and the messages can be effectively trialed at Whittle Dene. Farmers will respond to such advice, as payments are dependent on compliance. An established, and trusted consultant in the Whittle Dene area will be used to implement advice. The majority of this advice can be provided quickly after guidance is provided from Defra. At Whittle Dene, the slopes of the Brickfield soils are generally shallow to moderate, with a corresponding low perceived risk of soil erosion. This can be seen in Figure 5.2, which shows results for a soil erosion risk model run for the area around Whittle Dene (Morgan et al., 2001).

Figure 5.2 Risk of soil erosion by water in an average year around Whittle Dene There are, however, some fields where topography and drainage combine to produce locally significant erosion, with corresponding bare soil, and risk of run-off from agrochemicals and fertiliser. These losses are very significant in such a small burn, and when aggregated over a wider area, could be a large factor in water quality. Similarly, small blocks of commercial woodland on the moderate slopes of the Rivington series are common, and are a sediment source during and after felling if guidelines are not followed.

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Soil assessment (conducted in a dry year) has not revealed any structural problems, but if GAEC rules are followed, then there should be less risk of compaction or smearing. Where topsoil is dry, but subsoil is still plastic, there is potential to cause subsurface compaction, and this would be very difficult to assess. A significant area within this catchment is managed using minimum tillage methods. Where this is carried out under good conditions it tends to improve topsoil structure but under wet conditions compaction can be caused at the soil surface (Harris and Catt, 1999). There should be continued provision of advice on cultivation and establishment methods on heavy clay soils (e.g. SMI, 2005). There is limited effective underdrainage in the catchment. No modern drainage plans are available for most of the catchment, though 19th Century plans are available. Research has shown that some modern underdrainage was installed in the general area without using permeable backfill (p.f.), or by using peat or turf, which may have a limited life as p.f.. (see Section 3). These systems are still functional, but it is uncertain how effective they are. There is little incentive for tenant or landlord to conduct drain replacement or maintenance, especially under short-term tenancy agreements. A study on pesticide movement from Brickfield soil showed that effective mole drainage reduced the total amount of IPU being lost from the soil by a factor of four. This was because of attenuation of pesticide concentrations in soil water moving down through the soil profile to the mole channel, compared to being lost by shallow subsurface flow in undrained plots. However, mole drainage has not traditionally been used in the area. Therefore, attention should be given to advisory schemes on effective mole drainage techniques, or other methods, such as subsoiling or improved pipe drainage. It is apparent that road drainage is routed through fields. This can cause wet areas within fields and cause drains and ditches to flow during summer months. The extent of this problem, and implications for land management or water quality are not well studied. Burns and ditches are typically not well maintained. Where these have silted up, they should be cleared to maintain flow, and freeboard for underdrainage outfalls. Poorly maintained channels will cause drains to back up and become clogged, with implications for in-field water status and soil management. 5.6.2 WDWC, ELS and HLS The implementation of voluntary schemes offers more potential for poor uptake, or different interpretations. As already mentioned, there are many options under ELS/HLS and the project needs to ensure that these are selected carefully for each farm. The relevant technical specialists will liase with the farm consultant, farmer and landowner, to advise what options are desirable. A summary of water quality results from Phase I may help convince farmers of specific options if there is difficulty. The procedure for discussing specific implementation of the options (the plan) is likely to take considerable time and resources even though the general principles have been discussed with the farms concerned under Phase I. By agreement with Defra and the Rural Payments Agency (RPA), it is proposed to include all of the farmed land in the Catchment in the Entry Level Scheme. Under this arrangement, we would work with the farmers to produce the best combination of options, primarily to manage agricultural inputs to watercourses, with secondary landscape and wildlife benefits. The key components are listed and outlined below.

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• buffer strip along the burns and ditches in arable fields: the efficacy of this option to control soluble diffuse pollutants is questionable, but they are likely to have an impact on sediment, and sediment bound substances. There is circumstantial evidence that spray drift to the burn has caused significant peaks in pesticide concentrations and this evidence will be evaluated for the final report.

• Ditch maintenance: will improve habitats and improve drain outfalls, potentially

improving in-field drainage and allowing increased infiltration (free-flowing drains have been shown to reduce IPU losses on this soil type for this reason). The effect of drain improvement on the transport of other potential diffuse pollutants (e.g. N, P) in the Whittle Dene research catchment will be important to monitor.

• Low input grassland adjoining the burn: will reduce potential losses of nitrate

• Two key field corners out of production:

• seasonally wet area of grass field on margin of burn that is currently used for stock watering;

• a difficult arable field corner that is close to two large open field drains. • Soil management plan. • Crop protection management plan.

• Nutrient management plan.

Each of the above plans will be beneficial in encouraging profitable husbandry while in addition reducing the possibility of unnecessary inputs, reducing the risk of losses to watercourse and improving understanding of the relationship between land management and the aquatic environment. A detailed and integrated soil, nutrient, manure (where applicable) and crop protection management plan would be ideal for farms in the catchment. Cultural methods to control weeds should be given particular attention, especially in relation to recent arable land used for a typical rotation of wheat, with winter OSR or spring beans as a break crop. These plans should not be considered in isolation. The 2 m buffer may have a beneficial effect in reducing surface losses. However, such a buffer has the potential to be ‘saturated’ with fine sediment and there is uncertainty as to their effectiveness. 6-10 m set-aside buffers have more potential but, again, their effectiveness is not certain. Such buffers may gradually improve the structural condition of headlands that are close to watercourses, but should not be considered as a new ‘farm track’. Studies on traditional buffer strips show that they are by-passed by underdrainage systems, but in this case they may be more effective in removing substances and nutrients from shallow subsurface flow. The performance of such strips under these conditions may therefore merit study. Other options will be included as appropriate, and after discussion and agreement with the farmer. For example, the hill fort at Shildonhill might benefit from option C5 (archaeological features under grassland). Options that will have an impact on water quality will be included as a priority, but if other options are needed to meet the specified points target, there are substantial opportunities for wildlife and habitat options (e.g. low input fields, wild birdseed mixture, hedgerow management). Historically, monitoring would suggest that the traditional mixed agriculture caused less water pollution than intensive arable. This should be treated with caution, since monitoring and analytical methods have changed. However, it is likely that reversion of some ‘high risk’ fields to low-input grassland would reduce diffuse agricultural pollution. Marginal fields, which are prone to crop failure, should be put down to permanent pasture. Extensive beef and sheep production would be most applicable.

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Since pesticides are a major problem, a change to organic systems would be beneficial. However, the organic reversion on such heavy land is not straightforward and would not be practical without subsidy, improved margins and advisory schemes. Organic systems need to be managed carefully to control potential losses of nutrients. This option merits attention. There are many options under the Pilot ELS and HLS documentation that could be employed to benefit the soils at Whittle Dene. It should be noted that some diffuse emissions to water will be reduced by other options (e.g. stockproof fencing around the burn to prevent livestock access and appropriate alternative stock watering points). Supplementary options to benefit the water environment, such as the proposed Higher Level Scheme, could be deployed and evaluated at Whittle Dene. Since membership of the ELS is a prerequisite for the HLS, the implementation (or trial) of options under this scheme could be staged beyond 2005. Indications are that Whittle Dene will not be eligible under the HLS. It would be interesting to discuss if options to protect key water supply catchments (i.e. intended for abstraction for potable use) could be deployed. The area around Whittle Dene shows how important this is, since the water company and EA have no effective mechanism to interact with farm decisions on ‘high risk’ farms and fields. ADAS work in the Coquet (also in Northumberland) has identified key parts of the catchment that could also be targeted, for example. It would be possible (and perhaps preferable) to discuss this as the project progresses, as a way to ‘ratchet-up’ the options through time. There are options in the Higher Level Scheme that are highly desirable for inclusion in the catchment plan with immediate effect, and some for which timing is less critical. In common with the ELS, there are several options which should also be included to reflect regional habitat and biodiversity targets via the Biodiversity Action Plan (BAP). Documentation available at the time of drafting this document indicates that stock fencing will only be available under HLS. The grazed land at Whittle Dene includes significant areas that are not fenced from the Whittle Burn and associated watercourses. The concentrations of faecal indicators in water have been consistently high in these areas. Since ELS is a pre-requisite for HLS, there is concern that this important grant will not be available to a large number of farms. Fencing of watercourses represents a simple, cost effective way of reducing a range of potential agricultural pollutants (N, P, sediment, faecal material) and should ideally be included from the outset at Whittle Dene. Similarly, it is desirable to construct a bridge where the watercourse is crossed by livestock. 5.6.3 WDWC and voluntary additional options A range of options such as fencing or cattle bridges could be deployed with relative ease by the farmer (at quiet times of the year) or by a contractor. The project has identified several potential contractors in the area, and has experience with some of them during work for Phase I. The contractors are, therefore, trusted local companies with a good knowledge of the area and of the Whittle Dene project. In practice, these options should be planned in the winter of 2005, ready for installation in the spring and summer. The implementation of voluntary capital schemes will require careful consideration. The plan has identified what problems need to be addressed, the response and location, but a detailed plan of work is now needed for each option. ADAS is able to call on relevant specialists to plan such schemes, which include drainage remediation schemes and dirty water systems, for example. In common with the options recommended under the agri-environment schemes, these options will be planned carefully with the farmer in winter 2005, ready for installation in spring and summer.

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Drainage in arable fields at Shildonhill Farm is poor. Evidence suggests that a gas pipeline installed in the 1980’s caused significant drainage problems. There is a spring running across grass and arable fields to the Whittle Burn which causes significant soil erosion and crop failure. It is very unlikely that agricultural inputs are suspended where there is no crop, thus creating a significant potential source of pesticides and nutrients to the burn. The ‘Military Road’ (B6318) includes drains which run into the catchment. There is little problem where this occurs through open ditches. However, it is noticeable that the road drainage runs past the livestock unit at Vallum Farm where there is significant potential movement of faecal material. The road drainage should be diverted at this point to reduce the risk of farm runoff. The yard at Vallum Farm drains towards the Vallum Runner ditch, which joins the Whittle Burn. Samples from this point have indicated high concentrations of faecal material, nutrients and pesticides, and while not all will emanate from the yard, it still represents a significant potential source. The runoff from this yard should be either stored or treated. Options include a dirty water holding tank, or a constructed sedimentation pond. Runoff from pesticide mixing and handling areas has been shown to be a significant potential source of pesticides to drains and ultimately watercourses. Biobeds have the potential to reduce the risk of pesticides entering watercourses from pesticide handling areas. ADAS activity at Whittle Dene and the 500 km2 Coquet Catchment has revealed that farmers and pesticide users are very interested in this new technology. Farmers are, however, very conservative and are often led by their peers. A demonstration biobed at Whittle Dene would be an extremely valuable educational tool for the North East and is totally conducive to the theme of work at Whittle Dene. Ultimately, the catchment could be used as an educational facility and this demo unit would therefore be seen by a large number of relevant stakeholders. A suitable site would be the Vallum farm pesticide handling area, which is currently hardcore. Fencing and bridging is needed for many fields. Fencing stream banks restricts livestock access, and reduces the risk of faecal material entering the watercourse. Similarly, where access is across watercourses, it is highly desirable to construct a bridge to prevent direct deification into the stream. Much of the watercourses at Whittle Dene need fencing to prevent livestock access. Since the burn is commonly used as a watering point for livestock, it will also be necessary to install a water supply for fields used for grazing. ADAS ecological surveys, conducted as part of the Whittle Dene Project, supports earlier findings that the burn contains undesirable quantities of sediment. The main sources of the sediment are likely to be from arable fields at Shildonhill, and also a small woodland plantation felled in the early 1990’s. The stand at Shildonhill is likely to be felled during the life of the project. Plantations <10 ha are common in the North East, usually on unproductive or sloping land that can be vulnerable to erosion. It is recommended that dialogue continues with the landowner and Forest Enterprise. A low cost option (e.g. a bund) may be appropriate under these circumstances and may be more effective than equivalent use in larger forest plantations. 5.6.3.1 WDWC and the Voluntary Initiative on Pesticides Whittle Dene has been included as part of the Voluntary Initiative on Pesticides. The catchment is unusual in that it is the only one not to have any VI activities implemented, the plan being to collect baseline information on water quality and pesticide use. After

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discussion with the VI and NFU, the component parts of the VI which are considered to be most successful will be deployed to the Whittle Dene catchment. Thus, the catchment will benefit from experiences of other catchments collected over the past two years. The catchment will benefit from the introduction of VI Crop Protection Management Planning, for example. The farmers and contractors in the catchment are well aware of the VI. The objective for Phase II will be to ensure that the farms and spray contractors who operate in the catchment have taken part in the main components of the VI. For example, the project will work with spray operators to persuade them to take part in the National Sprayer Testing Scheme. It is important to use the Whittle Dene catchment to its greatest potential. The issues at Whittle Dene are not unique, and the catchment is representative of a large area of North-East England. Farmers are naturally conservative, and respond well to practical demonstrations. The catchment will therefore be used as a demonstration facility for local, national and international visitors (see Section x). Factsheets will be drafted throughout the project to explain the background, methods and results. ADAS has worked on similar issues in the 500 km2 Coquet Catchment and it is apparent that key areas of the Coquet are responsible for most of the pesticide water quality problems in the river. These areas have similar characteristics and soils to those at Whittle Dene. Thus, the demonstration facility will be important to regional environmental and economic targets. 5.7 Research plan It is probable that certain contaminants such as total P, and sediment, will not show a measurable change in water in the short-term. There is significant P bound in sediments, which will themselves take several years to work through a stream network. However, there is a much higher probability of measuring such changes in a small head water catchment such as Whittle Dene compared to higher order stream networks. Other more soluble substances such as IPU will show immediate reductions, while nitrate is rapidly lost from a system, but concentrations may remain seasonally high due to ‘pools’ of organic N which are mineralised to nitrate. Faecal contamination of watercourses, indicated by E.Coli, might be expected to be reduced immediately on implementation of mitigation techniques, (with a potential lag of oocysts in sediment). It is important to measure the changes in concentrations of these parameters in response to the implementation plan. Further, it is recognised that the weather, and rainfall in particular, is a driver behind peaks in concentrations. Monitoring must therefore continue over several seasons in order to balance any unusual effects of weather. This is a practical limitation of such monitoring of watercourses, but when used with appropriate surrogate indicators, such data can be interpreted usefully. For example, the concentration of nitrate in water will be interpreted against cropping, field history, N applications and the amount of soil mineral nitrogen measured in the relevant fields. For each year it will also be possible to conduct a nutrient balance for each holding, thus allowing an assessment of trends in nutrient surpluses. The project will, therefore, continue to conduct detailed monitoring of water, soil, fields and farms as detailed in Section 2. From this work, it will be possible to draw conclusions on source and impact of potential pollutants. The objective of the study conducted at the University of Newcastle is to monitor flow paths from fields to the burn. A key field has been identified and a network of peizometer nests has been installed. The aims of the research are to determine the behaviour of nitrate and phosphorus during storm events; to determine dominant hydrological flowpaths of nitrate and phosphorus at the field scale during storm events and link them to mechanisms of mobilisation and transport; and to produce recommendations of runoff management plans.

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Many invertebrate groups are good indicators of water quality. The project will include a survey of aquatic invertebrates, with a limited search of stream bottoms/margins and riparian habitats for species of conservation concern. Water samples will be collected from pre-determined points along the streams and ditches, in late spring and late summer each year. Samples will be examined in the laboratory and all captured macrofauna identified to species, family or order (as appropriate, partly depending on total numbers). Particular attention will be given to indicator species and groups, such as freshwater shrimps (Gammarus), caddis-flies (Trichoptera), stoneflies (Plecoptera), mayflies (Ephemeroptera) and dragonflies (Odonata). Additional targeted searches of stream bottoms and margins, within apparently suitable habitats, will aim to identify the presence of any invertebrate species of particular conservation concern e.g. crayfish (Astacus) and freshwater mussels. As in the previous study, monitoring will continue to focus on nitrate, phosphorus and pesticides. Associated parameters will include measurements of sediment and pathogens. Successful sample collection and processing are central to the overall success of the project and existing protocols will be followed or modified where necessary.

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MAFF (2000) Brimstone Farm III: Systems to minimise the leaching of pesticides to drainage water from a structured clay soil. Report No. PL0502 Macleod, C. and Haygarth, P. (2003) A review of the significance of non-point source agricultural phosphorus to surface water. Scope Newsletter Number 51, June 2003 Special Edition Mason, P.J., Foster, I.D.L., Carter, A.D., Walker, A., Higginbotham, S., Jones, R.L. and I.A.J. Hardy (1999). Relative importance of point source contamination of surface waters: River Cherwell catchment monitoring study. In: Proceedings of XI Symposium on Pesticide Chemistry. McGuckin, S.O., Jordon, C. and Smith, R.V. (1999) Deriving phosphorus export coefficients for CORINE land cover types. Water Science and Technology, V12, pp 47-53 Meeuwig, J.J., Kauppila, P. and Pitkanen, H. (2000) Predicting coastal eutrophication in the Baltic – a limnological approach. Canadian Jouranal of Fisheries and Aquatic Sciences, V57, pp 844-855 Moss, J.E., McErlean, S.A., Patton, M., Kostov, P., Westhoff, P. and Binfield, J. (2002). Analysis of the Impact of Modulation on Agriculture in the UK. NI-FAPRI Project: Agri-Food Policy Analysis Report No 6

Environmental Exposure to Xenobiotics, Cremona, Italy. Sept 11-15th 1999. La Goliardica Pavese s.r.l., 405-412. (ISBN 88-7830-299-6). Mason, C.F. (1996) Biology Of Freshwater Pollution. 3rd Ed, Harlow: Longman. Morgan, R.P.C (2001) A simple approach to soil loss prediction: a revised Morgan-Morgan-Finney model. Catena V44, pp305-322 Nicholson, F.A., Hutchison, M.L., Smith, K.A., Keevil, C.W., Chambers, B.J. and Moore, A. (2000) A Study On Farm Manure Applications To Agricultural Land And An Assessment Of The Risks Of Pathogen Transfer Into The Food Chain. Final Report to MAFF, FS2526 Nisbet, T.R. (2001) The role of forest management in controlling diffuse pollution in UK Forestry. Forest Ecology and Management 143, 215-226. Pell, A.N. (1997) Manure and microbes: Public and animal health problem. J.Dairy.Sci. 80:2673-2681. Shawyer, M.S. and Westcott, P. (1987) The Morecs climatological dataset – a history of water balance variables over Great Britain since 1961, Met. Magazine, V116: 205-211 Shepherd, M.A. 1993. Measurement of soil mineral nitrogen to predict the response of winter wheat to fertilizer nitrogen after application of organic manures or after ploughed-out grass. Journal of Agricultural Science, 121, 223-231. Shepherd, M.A., Hatch, D.J., Jarvis, S.C. & Bhogal, A. 2001. Nitrate leaching from reseeded pasture. Soil Use and Management, 17, 97-105. Shepherd, M.A., Barrie, I. Hossell, J., Harris, G., Perkins, S. Garstang, J. Buckley, D. Hillman, J., Lord, E., Harrison, R. Richardson, S. and Goodlass, G. (2001) A review of the impact of the wet autumn of 2000 on the main agricultural and horticultural enterprises in England and Wales. Report to Defra under contract CC0372

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Silcock, P., Swales, V., Smith, G. and Sealy, K. (2004) Impacts of CAP Reform Agreement on Diffuse Water Pollution From Agriculture. Final Report For Defra. GFA-RACE Partners Ltd, RAC, Cirencester, Gloucs, UK. Silgram, M. & Shepherd, M.A. (1999). The effect of cultivation on soil nitrogen mineralization. Advances in Agronomy, 65, 267-311. Silgram, M., Waring, R., Anthony, S. and Webb, J. (2001) Intercomparison of national and IPCC methods for estimating nitrogen loss from agricultural land. Nutr. Cycl. AgroEcosystems, 60, 189-195. SMI (2005) Target on Establishment. Soil Management Initiative, Mollington, Chester, UK. Smith, L.P. (1984) The Agricultural Climate of England and Wales. MAFF, London, HMSO. Stace, C. (1997). New Flora of the British Isles. 2nd edition. Cambridge University Press, Cambridge. Stott, T.A. and Mount, N.J. (2004) Plantation Forestry Impacts on Sediment Yields and Downstream Channel Dynamics in the UK: a Review, Progress in Physical Geography 28(2). The Royal Society (1983) Agriculture and Pollution; the Government Response to the Seventh Report of the Royal Commission on Environmental Pollution. Pollution Paper No.21 Trask, J.R. and Kalita, P.K. (2004) Overland and near-surface transport of Cryptosporidium parvum from vegetated and nonvegetated surfaces. J. Env. Qual. V33 pp984-993 Whitehead, D.C. 1995. Grassland Nitrogen. CAB International, Wallingford. Williams, R.J., D.N. Brooke, P. Matthiessen, M. Mills, A. Turnbull, and R.M. Harrison. (1995) Pesticide transport to surface waters within an agricultural watershed. J. Inst. Water Environ. Manage. 9:72–81 Willett, I.R. and Porter, K.S. (2001) Watershed Management for Water Quality Improvement: the Role of Agricultural Research. Australian Centre for International Agricultural Research, Canberra, Australia, Working Paper No.52 Withers, P.J.A. and Lord, E.I. (2002) Agricultural nutrient inputs to rivers and groundwaters in the UK: policy, environmental management and research needs. Sci. Tot. Env 282-283 pp 9-24 Withers, P.J.A., Edwards, A.C. & Foy, R.H. (1998) Phosphorus cycling in UK agriculture and implications for water quality. Journal of the Science of Food and Agriculture.

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APPENDIX 1. Vegetation Assessment at Whittle Dene

List of species found at Whittle Dene with some appropriate habitat information. Latin name English name Ellenberg F Ellenberg N Habitat notes Achillea millefolium Yarrow 5 4 A common plant of all kinds of rough grassland.1

Achillea ptarmica Sneezewort 7 3 A plant of meadows, commons, heaths, roadsides and streambanks on wet, acid to neutral, usually calcium-poor soils.1

Anthoxanthum odoratum

Sweet Vernal-grass 6 3 Found in a wide variety of habitats.

Apium nodiflorum Fool's Water-cress 10 7 Abundant and often dominant plant of shallow, nutrient-rich or calcareous dykes, ditches, streams and ponds.1

Arrhenatherum elatius False Oat-grass 5 7 A coarse grass, very common in rough grasslands.2

Caltha palustris Marsh-marigold 9 4 Primarily a plant of wet meadows, marshes, fens, ditches and wet woodland. It occurs on mineral soils of varying fertility.1

Catabrosa aquatica 9 7 Wet meadows, marshes, ditches, by ponds and streams, often on barish mud.3 Preferring rich soils.2

Centaurea nigra Black Knapweed 5 5 A plant of rough grassland.1

Cirsium arvense Creeping Thistle 6 6 Common plant of meadows, pastures, arable, roadsides and waste places, especially on fertile ground.1

Cirsium vulgare Spear Thistle 5 6 Common weed of cultivated land, roadsides, waste land and disturbed ground, especially on fertile, base-rich or calcareous soils.1

Conopodium majus Pignut 5 5 Plant of open woodlands, rough grassland, grass heaths, commons and hedge banks on well-drained, mildly acid soils.1

Crataegus monogyna Hawthorn 5 6 Wood-borders, scrub and hedges.3

Dactylis glomerata Cock’s.-foot 5 6 Coarse grass of meadows, pastures, roadsides and rough grassland.2

Deschampsia cespitosa

Tufted Hair-grass 6 4 A coarse [agriculturally] worthless grass of wet and badly drained soils.2

Epilobium montanum Broad-leaved Willowherb 6 6 Occurs in woodland, waste ground, walls, hedge banks, ditches [etc].1

Equisetum fluviatile Water Horsetail 10 4 Ponds, ditches, marshes, backwaters, in or by water.3

Filipendula ulmaria Meadowsweet 8 5 Common plant of marshes, fens, wet woods, streams, river and lake margins, damp ditches [etc].1

Fraxinus excelsior Ash 6 6 Woods, scrub and hedgerows. Often on damp soils.3

Galium aparine Cleavers 6 8 Abundant plant of hedgerows, ditches, scrub, stream and river banks [etc] and waste ground, usually on fertile soils.1

Galium verum Lady’s Bedstraw 4 2 Common plant of rough grassland.1

92

Appendix 1 (cont)

Geum rivale Water Avens 7 4 Common in wet meadows, marshes, fens, damp woodlands and hedge banks, stream sides [etc]. It prefers shaded conditions on fertile, base-rich or calcareous soils.1

Geum urbanum Wood Avens 6 7 Common in woodlands, scrub, hedgerows, roadsides and shaded habitats.1

Glyceria fluitans Floating Sweet-grass 10 6 In shallow water of ponds and lake margins,, in ditches, sluggish streams and river margins.2

Heracleum sphondylium

Hogweed 5 7 A plant of roadside verges, woodland clearings and rough grassland.1

Holcus lanatus Yorkshire Fog 6 5 Frequent as a weed in meadows and pastures. Often abundant in rough grassland on waste land [etc].2

Hypericum tetrapterum Square-stalked St. John's-wort

8 4 Frequent plant of damp grassland habitats.1

Juncus acutiflorus/articulatus

Sharp-flowered/Jointed Rush

8/9 2/3 Damp grassland, margins of rivers and ponds, etc.3

Juncus bufonius Toad Rush 7 5 All kinds of damp habitats, fresh-water and brackish, natural and artificial.3

Juncus effusus Soft-rush 7 4 Marshes, ditches, bogs, wet meadows, by rivers and lakes, damp woods.3

Lathyrus pratensis Meadow Vetchling 6 5 Plant of rough grassland, pastures, hedge banks, roadside verges.1

Lotus corniculatus Common Bird's-foot-trefoil 4 2 A wide variety of grassland habitats. Lychnis flos-cuculi Ragged-Robin 9 4 Common plant of wet meadows, marshes, fens and wet

woodlands.1

Malus sylvestris Crab Apple 5 6 Woods, hedges and scrub.3

Mentha aquatica Water Mint 8 5 A plant of stream, dyke, ditch, canal, river margins, wet meadows, marshes, fens and swampy woodland.1

Phalaris arundinacea Canary Reed-grass 8 7 Deep-rooting grass of wet places, margins of rivers, streams, lakes and pools.2

Potentilla erecta Tormentil 7 2 Found on grass heaths, commons and woodland rides and clearings in bogs and fens [etc].1

Primula vulgaris Primrose 5 4 Characteristic of woodland clearings, coppice, hedge banks [etc].1

Ranunculus repens Creeping Buttercup 7 7 Most characteristic of damp grassland, marshes and fens [etc].1

Rumex obtusifolius Broad-leaved Dock 5 9 Common plant of disturbed and trampled ground [etc] (includes roadsides and waterside habitats). It grows best on fertile soils.1

Rubus fruticosus Bramble 6 6 Common.

93

Appendix 1 (Cont)

Rubus idaeus Raspberry 5 5 Frequent plant of open woodlands, wood margins, heaths and commons on moist, usually sandy soils.1

Sambucus nigra Elder 5 7 Characteristic of disturbed ground and fertile, base-rich or calcareous soils, particularly where there has been some nitrogen enrichment.1

Sanguisorba officinalis Great Burnet 7 5 Grows in wet meadows, pastures, marshes and damp roadsides.1

Sonchus asper Prickly Sow-thistle 5 6 Common weed of gardens, arable, roadsides and waste ground on fertile soils.1

Sparganium erectum Branched Bur-reed 10 7 Grows in the shallow water of the margins of lakes, ponds, rivers, canals, dykes and streams on fertile, silty, muddy or peaty soils.1

Stachys officinalis Betony 5 3 A plant of permanent grassland [etc].1

Stachys palustris Marsh Woundwort 8 7 Frequent plant of pond, lake, stream, dyke, canal and river margins, damp ditches, fens and marshes, usually on moderately fertile soils.1

Stachys sylvatica Hedge Woundwort 6 8 Common plant of hedge banks, woodlands, shaded gardens and waste places on fertile soils.1

Ulex europaeus Gorse 5 3 Common on heaths, commons, rough land.1

Urtica dioica Common Nettle 6 8 A plant of woodlands, fens, ditches, and river and stream sides and habitats associated with man. It requires fertile soils and is especially characteristic of phosphorus-rich habitats.1

Valeriana officinalis Common Valerian 8 5 Frequent plant of the tall vegetation of marshes, fens, wet woodlands and ditch sides and also in rough grassland.1

Veronica beccabunga Brooklime 10 6 Frequent plant of the shallow margins of ponds, pools, rivers [etc] and in marshy patches in wet meadows usually on fertile or calcareous soils.1

Vicia cracca Tufted Vetch 6 5 Common plant of rough grassland and old pastures, roadsides, hedge banks [etc].1

1Garrard, I & Streeter, D. (1998). The Wild Flowers of the British Isles. Midsummer Books, London. 2Hubbard, CE. (1984). Grasses 3rd edition (revised by JCE Hubbard). Penguin Books, Harmondsworth, Middlesex. 3Stace, C. (1997). New Flora of the British Isles. 2nd edition. Cambridge University Press, Cambridge.

Appendix 1. (Cont)

Definition of Ellenberg Indices for F (Moisture) and N (Nitrogen, a general indicator of soil fertility).

Value Ellenberg F Ellenberg N 1 Indicator of extreme dryness, restricted to soils

that often dry out for some time Indicator of extremely infertile sites

2 Between 1 and 3 Between 1 and 3 3 Dry-site indicator, more often found on dry

ground than in moist places Indicator of more or less infertile sites

4 Between 3 and 5 Between 3 and 5 5 Moist-site indicator, mainly on fresh soils of

average dampness Indicator of sites of intermediate fertility

6 Between 5 and 7 Between 5 and 7 7 Dampness indicator, mainly on constantly moist

or damp, but not on wet soils Plant often found in richly fertile sites

8 Between 7 and 9 Between 7 and 9 9 Wet-site indicator, often on water-saturated,

badly aerated soils Indicator of extremely rich situations, often as cattle resting places or near polluted rivers

10 Indicator of shallow-water sites that may lack standing water for extensive periods

[not used]

11 Plant rooting under water, but at least for a time exposed above, or plant floating on the surface

[not used]

12 Submerged plant, permanently or almost constantly under water

[not used]

Nutrient status of the water body in which species are found (taken from Haslam et al., 1982). Species Nutrition Apium nodiflorum Oligotrophic to eutrophic Caltha palustris Eutrophic to oligotrophic Catabrosa aquatica Mesotrophic to eutrophic Equisetum fluviatile Wide range, not dystrophic Glyceria fluitans Mainly mesotrophic Juncus effusus Oligotrophic to mesotrophic Mentha aquatica Mesotrophic to eutrophic Phalaris arundinacea Mesotrophic to eutrophic Sparganium erectum Mesotrophic to eutrophic Veronica beccabunga Mesotrophic to eutrophic (oligotrophic)

94

95

APPENDIX 2

Average number of organisms collected at sampling locations along Whittle Burn and calculated biotic indices

Mean No. organisms collected from sample

locations:

Taxon BMWP score per taxon 1 4 7 8 9

Segmented worms OLIGOCHAETA 1 7 1 2

Leeches Glossiphoniidae 3 1 2 3 4 Molluscs Ancylidae 6 5 1 Sphaeridae 3 5 2 3 4 Lymnaeidae 3 1 11 10 Hydrobiidae 3 18 6 Shrimps Gammaridae 6 46 12 83 70 131 Beetles Scirtidae 5 4 39 1 2 Elminthidae 5 2 5 2 1 Gyrinidae 5 1 4 Haliplidae 5 2 4 Dytiscidae 5 2 4 14 Helophoridae 5 2 True flies Chironomidae 2 10 7 4 5 Tipulidae 5 3 5 Simuliidae 5 6 Ptychopteridae 5 3 Stone flies Leuctridae 10 1 12 Capniidae 10 6 Nemouridae 7 7 Caddis flies Rhyacophilidae 7 2 Polycentropodidae 7 3 Psychomyidae 8 6 4 Limnephilidae 7 5 9 9 4 4 Beraeidae 10 2 2 Glossosomatidae 7 2 25 Lepidostomatidae 10 3 Odontoceridae 10 1 Hydropsychidae 5 7 Sericostomatidae 10 1 3 May flies Ephemeridae 10 6 1 23 5 Baetidae 4 12 10 3 Heptageniidae 10 1 Leptophlebidae 10 5 5 1 Bugs Veliidae 5 9 1 2 7 Mesoveliidae 5 2 4 Gerridae 5 2 1 Figure 2 Nepidae 5 2 Notonectidae 5 1 Corixidae 5 5 15 Alder flies Sialidae 4 1 7 Number of taxa in sample 14 16 25 19 20 ASPT 6.64 5.56 6.48 4.89 4.80 BMWP 93 89 162 93 96

Analysis of variance (One-way ANOVA: Table 2a and b) was used to check for differences in biotic scores between the sampling sites. The Statistics programme used was Genstat (Lawes Agricultural Trust, 1998).

96

One-way ANOVA on BMWP scores for sampling sites Source of variation d.f. s.s. m.s v.r. F Sample site 4 11.0268 2.7567 7.36 0.001 ** Replicate 4 2.5874 0.6468 1.73 0.193 Residual 16 5.9963 0.3748 Total 24 19.6104

One-way ANOVA on ASPT scores for sampling sites Source of variation d.f. s.s. m.s v.r. F Sample site 4 7540.2 1885.1 8.72 <0.001 *** Replicate 4 29.4 7.4 0.03 0.998 Residual 16 3459.4 216.2 Total 24 11029.0

(significant difference, where *** represents p<0.001 and ** represents p<0.005)

APPENDIX 3 Whittle Dene Project Baseline Survey 2003 Western Catchment Fields

FORM FOR ARABLE FIELDS

Year Arable Fields

1 FIELD AND CROP DETAILS

Study Field Number

Area (Specify hectares or acres)

Crop Variety Soil characteristics Date of last soil analysis (excluding ADAS survey)

Results pH OM% P Index K Index Mg Index Other How are crops established? Plough Direct Drilled Furrow press/roll Power harrow/drill Minimal Cultivation Discs / cultivator Notes

Planting Broadcast Drilled Harrowed Date Comments Rate 2. PREVIOUS CROPPING Harvest Year

Crop Variety Yield ha/acre

2002 2001 2000

97

3. ROTATIONAL TREATMENTS

Crop year 01-02 (year/month)

Rate per ha/acre Current (02-03) year/month

Rate per ha/acre

Lime P FYM Slurry Subsoiling Mole drains Sludge 4. FIELD DIARY Fertiliser

Date Product N:P:K Quantity Kg/cwt etc

Field Rate % Field treated

Comments

Pesticides (Herbicides, Insecticides and Fungicides, slug killers) Date Product Water Vol

(L) Quantity

Kg/cwt etc Field Rate Kg ai/ha

% Field treated

Comments

98

5. HARVEST Year Estimated yield ha/acre Actual yield ha/acre Main Product By Product 6. POST HARVEST CULTIVATION Straw /stubble disposal method Removed Ploughed in Cultivated 7. FIELD DRAINAGE Date (if known) Plans available? Tiled Stone Plastic None Partial drainage Open ditches Piped ditches Comments

99

FORM FOR GRASS FIELDS Year 2002-2003 Grass

fields

1 FIELD AND CROP DETAILS

Field Number

Area hectares or acres

Permanent Grass Long Term ley Short term ley Soil characteristics Date of last soil analysis Results pH OM% P Index K Index Mg Index Other 2. PREVIOUS CROPPING Year Crop If arable, please give variety Yield

ha/acre 2001-02 2000-01 1999-2000 3. ROTATIONAL TREATMENTS

Previous (year/month)

Rate per ha/acre Current year/ month

Rate per ha/acre

Lime P FYM Slurry Subsoiling Mole drains Sludge

100

4. FIELD DIARY Fertiliser

Date Product N:P:K Quantity Kg/cwt etc

Field Rate % Field treated

Comments

Pesticides? Date Product Water Vol

(L) Quantity

Kg/cwt etc Field Rate % Field

treated Comments

5. HARVEST Year

Date Silage Hay Other Yield (kg/ha?)/ Bales

Comments

6. FIELD DRAINAGE Date (if known) Plans available? Tiled Stone Plastic None Partial drainage Open ditches Piped ditches Comments

101