HABITATS REGULATION ASSESSMENT SCREENING REPORT€¦ · HABITATS REGULATION ASSESSMENT SCREENING REPORT DROUGHT PLAN: ... 4.1 Ormesby / Bure Drought Action ... Reduce / stop compensation

DRAFT DROUGHT PLAN:

HABITATS REGULATION ASSESSMENT SCREENING REPORT

DROUGHT PLAN:

HABITATS REGULATION

ASSESSMENT SCREENING

REPORT

September 2017

DRAFT DROUGHT PLAN:


DOCUMENT CONTROL SHEET

Report Title : Drought Plan: Habitats Regulation Assessment Screening Report

Report Author: NWG Water Resources Team

Distribution List :

Internal :

Head of Technical Strategy & Support & Water Resources Project

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External :

Environmental Agency and Natural England

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REVISIONS

Version Report Status Signed off by Issue Date

1 Draft Will Robinson 15 September 2017

2

EXCLUSIONS ON THE GROUNDS OF NATIONAL SECURITY

Under Section 37B(10)(b) of the Water Industry Act 1991, as amended by the Water

Act 2003 (“the Act”), the Secretary of State can direct the Company to exclude any

information from the published Plan on the grounds that it appears to him that its

publication would be contrary to the interests of national security. Northumbrian

Water Limited has excluded some information from this plan on the grounds that the

information would be contrary to the interests of national security.

Disclaimer: This report is intended as confidential to the individuals and or companies listed on the

distribution list. Essex & Suffolk Water accept no responsibility of any nature to any third party to whom

this report or any part there of is made known.

Essex & Suffolk Water is a trading division of Northumbrian

Water Limited which is a group company of Northumbrian

Water Group

Registered in England & Wales No. 2366703

Registered Office:

Northumbria House, Abbey Road

Pity Me,

Durham DH1 5FJ

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CONTENTS

1 INTRODUCTION ............................................................................... 5

1.1 Background ...................................................................................................................5

1.2 Habitats Regulations Assessment ..............................................................................5

1.3 Report Purpose .............................................................................................................5

2 APPROACH ...................................................................................... 6

3 STAGE 1A: SCREENING .................................................................. 8

3.1 European Site Identification ........................................................................................8

3.2 Conservation Objectives for Identified Sites .......................................................... 13 The Broads .......................................................................................................................... 13 Alde-Ore Estuary ................................................................................................................. 16 Waveney & Little Ouse Valley Fens (Redgrave and Lopham Fen SSSI) ........................... 17

4 STAGE 1B: IMPACT IDENTIFICATION .......................................... 19

4.1 Ormesby / Bure Drought Action ............................................................................... 19

4.1.1 Drought Action ........................................................................................................... 19

4.1.2 Environmental Assessment ..................................................................................... 20

4.1.3 Stage Three: Assessment of Mitigation and Alternatives ..................................... 21

4.2 Redgrave Group Licence .......................................................................................... 23

4.2.1 Drought Action ........................................................................................................... 23


4.2.3 Stage three: Assessment of Mitigation and Alternatives ...................................... 24 Alternatives ........................................................................................................................ 24 Mitigation ............................................................................................................................ 24

4.3 Saxmundham Daily Licence ..................................................................................... 24

4.3.1 Drought Action ........................................................................................................... 24


4.3.3 Stage three: Assessment of Mitigation and Alternatives ...................................... 25

5 CONCLUSIONS & RECOMMENDATIONS ...................................... 27

6 REFERENCES ................................................................................. 28

Environment Agency (2011) Water Company Drought Plan Guideline, Environment Agency

............................................................................................................................................. 28 Essex & Suffolk Water (2011) Draft Drought Plan, Essex & Suffolk Water ........................ 28 Essex & Suffolk Water (2011) Drought Action Environmental Reports: .............................. 28 Ormesby / Bure Licence: Trinity Broads .............................................................................. 28 Ormesby / Bure Licence: Bure Broads & Marshes .............................................................. 28

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Coldfair Green and Leiston Boreholes ................................................................................ 28 Saxmundham Daily Licence ................................................................................................ 28 Redgrave Group Licence ..................................................................................................... 28 Wortham Compensation Discharge ..................................................................................... 28 Lound Annual Licence ......................................................................................................... 28 Bedingfield Annual Licence ................................................................................................. 28 Waveney Augmentation Groundwater Scheme .................................................................. 28 Stour Augmentation Groundwater Scheme ......................................................................... 28 Sandon Brooke Compensation Discharge .......................................................................... 28 UKWIR (DRAFT 2011) Strategic Environmental Assessment and Habitats Regulation

Assessment of Drought Plans Draft Guidance, Cascade Consulting ................................. 28

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1 INTRODUCTION

1.1 Background

Northumbrian Water Limited (NWL) has reviewed and updated its current

Essex & Suffolk Water Drought Plan in line with the Environment Agency’s

Drought Plan Guidance (2016).

The Drought Plan contains drought actions near to sites of European

importance for Nature Conservation and so as a competent authority, NWL is

required to undertake a Habitats Regulation Assessment (HRA) screening to

identify drought actions that could have likely significant effects on European

sites.

1.2 Habitats Regulations Assessment

The European sites include:

Special Areas of Conservation (SACs) designated under the Habitats

Directive which protect habitats and non-avian species of European

importance;

Special Protection Areas (SPAs) designated under the Birds Directive

which protects bird species of European importance; and

areas designated as globally important wetlands under the Ramsar Convention (1971).

The purpose of HRA is to consider the impacts of the Drought Plan against

the effected European site’s conservation objectives to ascertain whether the

site integrity would be significantly affected. Where likely significant effects are

identified, alternative options should be examined else imperative reasons of

over riding public interest must be demonstrated.

1.3 Report Purpose

This report is the HRA Screening Report to support ESW’s Drought Plan.

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2 APPROACH

The full HRA process is as follows:

Stage One: Screening Stage

This stage is used to establish whether Appropriate Assessment is required

by identifying whether supply side drought actions within the Drought Plan are

likely to have significant effects on the designated features of European sites.

This stage comprises European site identification followed by environmental

impacts screening where the following are considered:

Effect type Effect mechanism Effect significance

Likely significant effects are those that can not be ruled out using objective

information.

Stage Two: Appropriate Assessment (AA)

Where it is not possible to determine no likely significant effect, an Appropriate

Assessment will be undertaken by ESW.

This stage considers the implications of the supply side drought actions in

respect of a European site’s conservation objectives so that conclusions can

be drawn as to whether the Drought Plan is likely to have “significant effects”

on a site’s designated features.

The Environment Agency’s regional models were used for its Review of

Consents (RoC) process to establish whether existing abstraction licences

have likely significant effect on European Sites. Soil moisture and

groundwater levels were modelled based on full abstraction licence utilisation.

Where modelled soil moisture and groundwater levels met target soil moisture

and groundwater levels, a conclusion of no likely significant effect was

concluded.

To inform the Drought Plan Appropriate Assessment, it would therefore be

appropriate for ESW to request a further model run based on a fully licensed

scenario plus the increased quantity required as part of the drought action.

The Environment Agency is the competent authority under the Habitats

Directive for drought permit applications and will carry out an Appropriate

Assessment for any future permit applications. The Environment Agency

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considers it acceptable that the Drought Plan has control mechanisms in

place so that if a drought option requires Appropriate Assessment before

implementation, the work is triggered well in advance of when a permit/order

application would be needed. ESW supports this approach although still

plans to undertake the additional model runs that are required to undertake

the appropriate assessment during 2012 (i.e. after the likely publication of the

Drought Plan but well in advance of when a permit/order application would be

needed).

ESW has prepared an environmental report for each of the supply side

drought actions with the Drought Plan. The environmental monitoring data

together with the environmental assessment in these reports will also be used

to inform the Appropriate Assessment.

Stage Three: Assessment of Mitigation and Alternative Solutions

Where likely significant effects are identified at the Appropriate Assessment

stage, mitigation measures will be identified in order to reduce to an

acceptable level, the likelihood, severity and duration of the effect.

Where likely significant effect remains after mitigation, alternative options will

be examined.

Stage Four: Monitoring

Should the Appropriate Assessment be able to conclude no likely significant

effect, there will still be a comprehensive monitoring programme in place (see

the environmental monitoring plan in each of the environmental reports), to

ensure that once the drought action is implemented, that there is in fact no

significant effect.

Stage Five: Imperative Reasons of Over-riding Public Interest (IROPI)

Should it not be possible to determine no likely significant effect, and where

no other alternative feasible options can be identified, ESW would have to

justify on grounds of public health, safety or beneficial consequences to the

environment, Imperative Reasons of Overriding Public Interest (IROPI) in

order for a drought action within the Drought Plan to proceed. Additionally,

ESW would still be required to take appropriate compensatory measures to

ensure the overall coherence of the European sites is protected.

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3 STAGE 1A: SCREENING

3.1 European Site Identification

ESW’s Geographical Information System (GIS) APIC has been used to plot

the location of both supply side drought action abstraction points and

European sites. A large scale plot is shown in Figure 1 overleaf.

Based on this GIS review and a review of Review of Consents Stage 4 Site

Action Plan Reports, the following drought actions are deemed to be in the

same groundwater catchments as a European site, are therefore likely to

affect a European site and will therefore be subject to HRA:

Increase restricting annual quantity on Redgrave Group licence Increase restricting Saxmundham Daily Licence Increase restricting annual quantity on Ormesby / Bure Group licence

Further information on the potential environmental effects is provided in

section 3.2.

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Figure 1: Drought Actions and European Sites

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Table 1: Drought Actions HRA Screening

Drought Action SSSI European

Site

European Feature Potential

Mechanism

Alone or In-

combination

Effect

Significant

Effect

Reason

Reduce / stop compensation

discharge from Wortham

borehole to Wortham Pond,

Wortham Meadows and the

River Waveney

No No N/A N/A N/A N/A Although the Wortham abstraction

is in close proximity to Redgrave

and Lopham Fen SSSI, the

compensation discharge benefits

land that is outside of the European

site.

Increase restricting annual

quantity on Redgrave Group

licence

Redgrave

& Lopham

Fen

Waveney

& Little

Ouse

Valley

Fens

Calcareous Fens with

Cladium mariscus and

species of the Caricion

davallianae

Molinia meadows on

calcareous, peaty or

clayey-silt-laden soils

(Molinion caeruleae)

Additional drawdown

in Chalk aquifer

leading to reduce

groundwater

discharge and lower

soil moisture.

Alone No Although Wortham borehole is

located in close proximity to

Redgrave and Lopham Fen SSSI,

the additional abstraction would

take place from Mendlesham and

Eye boreholes which are not in

close proximity to a European site.


quantity on Bedingfield

licence

No No N/A N/A N/A N/A No European sites in close

proximity to abstraction.

Increase restricting daily

quantity on Saxmundham

licence

Alde / Ore

Estuary

Marsh Harrier (B); Ruff

(W); Redshank (W);

Avocet (W) (SPA); and

Atlantic Salt Meadows

(incl Saltmarsh);

Grazing marsh;

Estuaries (Shallow

Coastal Waters); and

Mudflats and sandflats

not covered by sea

water at low tide

(Intertidal mudflats and

The Saxmundham

Treatment Works

abstraction has the

potential to reduce

baseflows to the

River Fromus and

River Alde and

therefore freshwater

flows to the Alde

Estuary.

Alone No Although the abstraction has the

potential to marginally reduce

baseflow to the River Fromus, River

Alde and freshwater flows to the

Alde / Ore Estuary, a compensation

discharge at Benhall TWs would

mitigate against this reduction in

baseflow to the river, therefore

maintaining an MRF to the Alde

Estuary. This compensation

discharge has already been

identified as the RoC solution for

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Site


Mechanism

Alone or In-

combination

Effect

Significant

Effect

Reason

sandflats) (SAC) the Benhall Group Licence.

Additionally, infrastructure is

already available to make the

compensation discharge.

Reduction / cessation of

compensation flows from

Coldfair Green and Leiston

Boreholes

Yes No N/A N/A N/A N/A No European sites in close

proximity to abstraction or to

compensation discharge receptors.

Increase annual licence and

April to Oct quantities on

Lound licence.


proximity to abstraction


quantity on Ormesby/Bure

licence.

Trinity

Broads

SSSI &

Bure

Broads &

Marshes

SSSI

Broadland

SPA and

Broads

SAC

See Section 4.1.3

below.

Reduced river and

therefore wetland

groundwater levels

There are

other non-

PWS surface

water

abstractions

although these

are likely to be

restricted by

the time this

drought action

would be

wanted.

No The marginal increase in annual

licence would be abstracted from

the River Bure. The RoC

assessment was based on 100% of

the annual licence being abstracted

from the River Bure and this

concluded no likely significant

effects. The drought action would

not result in abstraction above the

existing daily licence.

Increase Stour Groundwater

Augmentation Scheme

(SAGS) 18 Month Licensed

Quantity


proximity to abstraction

Reduce or Cease Sandon

Brook Compensation

No No N/A N/A N/A No No European sites in close

proximity to abstraction or to

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Site


Mechanism

Alone or In-

combination

Effect

Significant

Effect

Reason

Discharge from Hanningfield

Reservoir

compensation discharge receptors.

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3.2 Conservation Objectives for Identified Sites

The Broads

The following conservation objectives are for the Broads SAC and Broadland

SPA and so cover both the Trinity Broads and Bure Broads and Marshes

SSSIs.

Broads SAC

Subject to natural change, to maintain* in favourable condition the Annex I habitat features: Hard oligo-mesotrophic waters with benthic vegetation of Chara spp; Natural eutrophic lakes with Magnopotamion or Hydrocharition type vegetation; Transition mires and quaking bogs; Calcareous fens with Cladium mariscus and species of the Caricion davallianae; Alkaline fens; Alluvial forests with Alnus glutinosa & Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae); Molinia meadows on calcareous, peaty or clayey silt laden soils (Molinion caeruleae) Subject to natural change, to maintain* in favourable condition the habitats supporting populations of Annex II species Desmoulin’s Whorl Snail Vertigo moulinsiana; Fen Orchid Liparis loeselii; Otter Lutra lutra. Broadlands SPA

to maintain*, in favourable condition, the habitats for the populations of the

Annex 1 bird species – Bittern, Marsh Harrier, Bewick’s Swan, Hen Harrier,

Ruff, Whoopers Swan, AvocetΔ, Golden PloverΔ, Common TernΔ

to maintain*, in favourable condition, the habitats for the populations of the

regularly occurring migratory bird species - Gadwall, Pink-footed Goose,

Shoveler, LapwingΔ

to maintain*, in favourable condition, the habitats for the populations of

waterfowl that contribute to the wintering waterfowl assemblage.

with particular reference to Open water, Swamp, Fen, Reedbed, Fen meadow

with ditches and water bodies, lowland wet grassland with ditches and water

bodies, wet woodland, saltmarsh, lowland acid grassland with ditches

* maintain implies restoration if the feature is not currently in favourable

condition.

+ Are the SPA features listed in the SPA review and not on the citation. Δ Are the SPA features listed in the citation but not in the SPA review

Natural England support the view that the degree of natural functioning within

the Broads should be increased and that while historically the Broads would

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have functioned as a natural estuary/floodplain, man has intervened with the

natural functioning over many centuries. Where these interventions occurred

centuries ago and land levels have reduced opportunities to reinstate a more

natural function may not be desirable, for it would lead to significant damage

to designated wildlife features. In these situations the desirable environmental

outcome is to maintain the present functioning. This applies to the Trinity

Broads.

Natural England goes onto to say that where man’s interventions on sites

have been more recent or where a more-natural functioning has been

maintained the environmental outcome should be to increase natural

functioning.

The following feature specific outcomes have been set by Natural England.

Alkaline Fen

Functionality criteria underpinning environmental outcomes:

a) High groundwater table to support shallow rooting (Carex species) and mosses (with no or very limited functional water transport tissue) throughout the year.

b) Continuous groundwater discharge in winter and summer (non-drought years); the supply of calcium rich often supersaturated groundwater needs to FLUSH the soil, so that the right chemical (i.e. redox and Ca) balance in the soils is maintained.

c) The competition processes that determine the required (M13) vegetation are dominated (Source Bryan Wheeler, Sheffield Uni) by exclusion processes (exclude species) rather than inclusion (i.e. enough water to grow optimally). This exclusion process is mainly due to the anoxic – low REDOX soil conditions with high concentrations of toxins such as Sulphide. This in its turn is dependent upon a continuous high water table throughout the year.

For M13 groundwater level targets have been used:

1) The average ‘normal year’ shallow groundwater table should throughout a

normal year not drop more than 10cm below ground level.

2) The variability of the groundwater level in a ‘normal year’ should not drop

under 1 SD from 10cm below ground level, e.g. -22.4 cm.

3) The duration, frequency and intensity of drought periods should not be

significantly increased by abstraction or surface water management

Alluvial Forests

The generic water level target for alluvial woodland W5 and W6 is:

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1) Winter water-levels at or very near the ground surface 2) spring water levels should be maintained within 5 cm of the ground

surface. 3) Summer maximum and minimum levels should be between 5 and 45 cm

below the ground surface, accepting that optimal seedling growth occurs with water levels between 10 and 30 cm below ground level. This should maintain the typical canopy and under-storey species.

No data are available on the requirements of W2 woodland, which also

contributes to the European feature. It is therefore proposed that the target

regime described above applies to this community.

Calcareous Fen With Cladium spp.

For the S24, the target identified is:

1) Summer water table should be between 3 cm above and 36 cm below ground level in the summer months (July to September). This is the mean

water level for S24 on a number of sites across East Anglia 1SD (but curtailing the maximum water table to water at 4 cm above ground level as measured).

2) Winter water levels are expected to be at the surface.

Natural Eutrophic Lakes and Hard Oligo-Mesotrophic Waters With Benthic

Vegetation of Chara spp. in Drainage Systems

The target for these two lake types requires that inflow to the site should not

be reduced by more than 10% of naturalised Q95 river flow.

As a precautionary approach it is suggested that for ditches an effect will be

considered adverse if it results in a change in level of more than 10% of the

ditch depth, or water levels are lower than 45 cm.

Transition Mires and Quaking Bogs

The transition mire community M5 occurs on the fen surface (not floating) and

is thus potentially sensitive to water level fluctuations. Water levels should not

fluctuate more than 30 cm annually.

Molinia Meadows

The target for the M24, which is derived from the ‘Ecohydrological Guidelines’

is that the summer water table should be between 10 and 41 cm below

ground level in the summer months (July to September). This is the mean

water level for M24 on a number of sites across East Anglia 1SD (but

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curtailing the maximum water table to water at 10 cm below ground level as

measured)1.

Desmoulin’s Whorl Snail

The target requires the water table to remain within 0.2 m of the ground

surface for 9 months of the year, with a critical minimum level of -0.5 m below

ground level in the summer. Flooding to 0.6 m depth is acceptable for limited

periods in some locations.

Fen Orchid

This was also considered sensitive but where present was generally

associated with either Molinia meadows or Calcareous fen habitat and

therefore these habitat features targets are to be used.

Given the water dependant nature of the Trinity Broads and Bure Broads and

Marshes designated features, these sites are likely to be sensitive to a

drought action to increase abstraction. This is because additional abstraction

could reduce water levels and flows and therefore reduce fen groundwater

levels and water body flushing rates.

Alde-Ore Estuary

The Alde-Ore Estuary is located on the Suffolk coast with the main freshwater

input to the estuary being the River Alde. Other inflows include the Butley

Rivers, as well as a number of smaller inflows and groundwater seepages

from underlying Crag aquifers.

The European features of the Alde Ore Estuary SPA and Alde, Ore and Butley

Estuaries SAC are as follows:

Alde-Ore Estuary SPA

Marsh Harrier (Circus aeruginosus)

Ruff (Philomachus pugax)

Avocet (Recurvirostra avosetta)

Little Tern (Sterna albifrons)

Sandwich Tern (Sterna sandvicensis)

Lesser black backed gull (Larus fuscus)

Redshank (Tringa totanus)

A seabird assemblage of international importance (breeding): herring gull,

black-headed gull, lesser black-backed gull, little tern, sandwich tern

1 For normally distributed data this range will pick up 70% of the occurrences of situations for M24.

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A wetland of international importance (over wintering): black-tailed godwit,

shoveler, teal, wigeon, shelduck, redshank, and avocet. Dunlin, lapwing and

white-fronted goose

Shingle areas

Intertidal mudflats

Saltmarsh communities

Shallow coastal waters

Grazing marsh

Alde, Ore & Butley Estuaries SAC

Estuaries

Atlantic salt meadows (Glauco-Puccinellietalia maritimae)

Mudflats and sandflats not covered by sea water at low tide

The bird populations within the Alde-Ore Estuary are in part reliant on the

freshwater flows from the River Alde. Consequently, the site is likely to be

sensitive to a drought action to increase groundwater abstraction as this could

reduce base flow to the river Alde.

Waveney & Little Ouse Valley Fens (Redgrave and Lopham Fen SSSI)

Redgrave and Lopham Fens SSSI forms part of the Waveney and Little Ouse

Valley Fens SAC. The site includes the source of the River Waveney fed by

springflows discharging from the underlying Chalk and drift aquifers. The flora

of the site mainly comprises wetland vegetation including herbaceous fen,

reedbed, woodland (including alder woodland) and dry grassland.

The European features of interest are:

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Annex I Habitat

Type

NVC

Commun

ity type

Stage 3 Target

Calcareous Fens

with Cladium

mariscus and

species of the

Caricion

davallianae

S2 Water table between 40cm above and 15cm below

ground level, with standing water present between

tussocks.1

S24c The summer water table should be between 40cm

below ground level and 4cm above ground level,

and winter water levels would be expected to be

above ground level for at least some of the winter

period.2

S25 No significant reduction in the flux of groundwater

flowing to these communities. Allowing for natural

seasonal variation, water table to drop no more

than 20cm below ground level in summer.1

Molinia

meadows on

calcareous,

peaty or clayey-

silt-laden soils

(Molinion

caeruleae)

M24 Summer water table should be between 10 and 41

cm below ground level in the summer months (July-

Sept). This is the mean water level for M24 on a

number of sites across East Anglia ±1SD (but

curtailing the maximum water table to water at 10

cm below ground level as measured). Winter water

levels are expected to be just sub-surface.2

As the site is groundwater dependant, the European features of interest are

likely to be sensitive to a drought action that could increase groundwater

abstraction.

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4 STAGE 1B: IMPACT IDENTIFICATION

4.1 Ormesby / Bure Drought Action

4.1.1 Drought Action

ESW is currently licensed to abstract a combined total of 10,000 Ml per year

from the River Bure at Belaugh, from Ormesby Broad and from four Chalk

boreholes adjacent to the River Bure at Juby Farm and Grange Farm.

Additionally, the governing abstraction licence (number 7/34/9/GS/54)

indicates that abstraction from the sources must not exceed 7,500 Ml in the

period from April to October inclusive.

The current annual licence quantity is usually approached every year with

utilisation often exceeding 92%. The annual licence has previously been

restricting during periods of drought, hence an appropriate increase via

drought permit/order may release additional water for supply in dry years.

Consequently, the drought action is:

to apply for a drought permit/order to increase the licensed annual quantity of water that can be abstracted from Ormesby Broad and the River Bure. A suggested increase would be from 10,000 Ml to 10,500 Ml (5% increase); and

to apply for a drought permit/order to increase the quantity of water that can be abstracted during the period April to October inclusive. A suggested increase would be from 7,500 Ml to 7,875 Ml (5% increase).

The additional 500 Ml/annum would be abstracted from the River Bure, most

likely between April and August (153 days), when peak demands are usually

at their highest. It is important to note that while the marginal increase in

annual licence is equivalent to 3.3Ml/d between April and August, abstraction

would still remain within the current Bure daily licence of 27.2Ml/d.

Abstraction from the Grange Farm and Juby Farm Chalk boreholes, located at

Belaugh, would not increase as a consequence of this drought action. Use of

the Belaugh boreholes is not restricted, although the Company operates them

as emergency use boreholes, usually when abstraction from the River Bure is

not possible because of turbidity or high nitrates during high flow events. In a

typical year, only 100 Ml/annum (0.1% of the annual licensed quantity) is

abstracted from the boreholes. This is because the groundwater has elevated

silicates which can cause a diatom bloom in the bank-side storage reservoir at

Ormesby TWs. This makes the water difficult to treat because the diatoms

blind the filters, and more expensive to treat because it required the use of

additional chemicals. Although not always the case, summers are often

warmer during drought years, which would further increase the risk of diatom

blooms in the bank-side storage reservoir. Consequently, using the Belaugh

boreholes would be less desirable in a drought year than in a normal year.

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4.1.2 Environmental Assessment River Bure

An increase in annual abstraction from the River Bure at Belaugh could

reduce downstream river flow. However, as described in the Stage 4 RoC

assessment, river levels are unlikely to be significantly effected as the River

Bure is tidal and so any reduction in river level arising from increased

abstraction would be balanced by incoming tidal water further downstream.

However, this might allow the saline interface to move further upstream and

allow saline intrusion during periods of low flow.

Environmental monitoring undertaken by ESW has shown that the only

increases in conductivity/salinity, detected during the monitoring programme,

were a consequence of winter tidal surges. There was no observed increase

in conductivity/salinity during summer low flow periods, although the

monitoring period did not include a notable drought, such as that in 1996/97.

Therefore, conductivity/salinity monitoring will continue as part of the

environmental monitoring plan.

The Agency confirmed that a fully licensed (worst case) abstraction scenario was assessed as part of its Review of Consents assessments. This assumed that the full annual licence (10,000Ml) was abstracted from the Bure intake at a rate of 27Ml/d (the daily licence) for 365 days per year. It concluded that from a salinity perspective, there is sufficiently low risk associated with real fully licensed abstraction and that environmental outcomes are likely to be achieved. Since the existing River Bure maximum daily quantity at Belaugh is 27.2Ml/d, and ESW is not intending to exceed this, any effect on saline incursion should not be any greater than that considered in the RoC assessment. In summary, ESW concludes that the drought action in not likely to cause significant effect.

Bure Broads & Marshes European Features of Interest

Environmental monitoring undertaken by ESW has shown that fen

groundwater levels are controlled largely by water levels in the main River

Bure which in turn are influenced by tide. As described above, abstraction is

unlikely to significantly effect river levels and therefore unlikely to effect Fen

groundwater levels and discharge.

The European features of interest are groundwater dependant. The Agency’s

Site Action Plan states that there is likely to be a Chalk groundwater

contribution, although this is thought to be constrained by confining peat. The

potential for Chalk groundwater discharge to surface can in turn be influenced

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by abstraction from the Chalk aquifer. However, as described above, this

drought action will not result in increased utilisation of the Belaugh boreholes.

In summary, ESW concludes that the drought action in not likely to cause

significant effect.

Trinity Broads

ESW’s AMP4 NEP investigation and the Agency’s RoC process concluded

that recent actual Broad abstraction (i.e. ~4,000Ml/annum) is sustainable from

a water balance perspective (i.e. water inflows = water outflows). However,

monitoring data and a bathymetric survey have shown that the conservation

objective target to maintain a minimum Broad water depth of 30cm across the

extent of the Broads, is not always met. Consequently, the abstraction licence

has been modified to include an abstraction cessation level of -0.44mAOD

subject to an agreed programme of sediment removal (mud pumping) which

has now been completed.

The Ormesby/Bure drought action is to increase the combined annual licence

from 10,000Ml/d to 10,500Ml/d. However, this additional water will be taken

from the River Bure. Consequently, it is also possible to conclude no likely

significant effect when considering the effect of the drought action on the

Trinity Broads SSSI.

4.1.3 Stage Three: Assessment of Mitigation and Alternatives This section considers whether there are alternative drought actions that could

be implemented and if not, what mitigation measures could be employed to

prevent any adverse environmental effects that might be observed following

implementation of the drought action.

Alternative Drought Actions

As described in Sections 8 and 9 of the Drought Plan, the following drought

actions would always be implemented prior to applying for a drought order to

increase the Ormesby/Bure annual licence:

Appeals for restraint (1 in 20 Years Level of Service)

Suspension of mains flushing

Temporary Use Ban (1 in 20 Years Level of Service)

Drought Order Ban (1 in 50 years Level of Service)

Increase Lound annual licence

Tankering

DRAFT DROUGHT PLAN:


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Mitigation

Ormesby Broad Abstraction Regime

ESW’s AMP NEP investigations and the Agency’s RoC investigations

concluded that there is a fine balance between Broad inflows and outflows

and that an abstraction regime where 60% of the annual licence

(10,000Ml/annum) is abstracted from the Bure and 40% from the Broad is

considered sustainable. Consequently, if the drought action was permitted,

the Agency would not want to see more than 4,000Ml/annum (i.e. 40% of the

current annual licence) being abstracted from the Broad. Therefore, ESW has

implemented anew abstraction management regime in order to maintain

Broad abstraction below 4,000Ml/annum. The revised regime (see Figure 2

below) will result in less water being taken from the Broad and more from the

Bure when Broad levels are lower, thus Broad levels should remain higher

than they have historically been.

Figure 2: Proposed Ormesby Broad Abstraction Regime

Increased Lound Supply Zone Transfer to Ormesby Supply Zone

The Ormesby Broad and River Bure abstractions are located within ESW’s

Northern Central Water Resource Zone.

Given the European importance of the Trinity Broads and the Bure Broads

and Marshes, as a drought develops and once a drought is called,

DRAFT DROUGHT PLAN:


23

abstractions from Lound and Barsham would be maximised to conserve both

the Ormesby/Bure annual licence and also resources in Ormesby Broad.

Given that Fritton and Lound lakes are not SSSIs, it is likely that the Lound

drought action would be implemented prior to the Ormesby/Bure drought

action.

4.2 Redgrave Group Licence


The Redgrave Group Licence (number 7/34/16/G/48) allows abstraction from

a number of groundwater sources as follows:

Source Daily Licence (Ml/d) Aquifer

Source 1: Eye 1.091 Chalk

Source 2: Mendlesham 0.9 Chalk

Source 3: Wortham 3.637 Chalk

Source 4: Syleham 5.364 Chalk & Crag

The annual licensed quantity for all the sources combined is 2,500 Ml/yr. This

quantity has previously been approached and/or exceeded during drought

periods in the 1990’s. Consequently it may be prudent in a future drought

period to increase the annual quantity as this is the key limiting factor.

The drought action is to apply for a drought permit/order to increase the

annual quantity of the Redgrave Group licence. A suggested increase would

be from 2,500 Ml/yr to 3,000 Ml/yr.

The additional licensed annual quantity would be abstracted from Syleham,

Mendlesham or Eye rather than at Wortham, which is closest to Redgrave and

Lopham Fen SSSI.

4.2.2 Environmental Assessment

The only European site within the cone of depression of Wortham borehole is

Redgrave & Lopham Fen SSSI. Abstraction from Wortham Borehole can

lower Chalk groundwater levels, which in turn can reduce groundwater

discharge to the fen. However, the Agency’s Review of Consents process

concluded that fully licensed abstraction under the existing abstraction licence

conditions is unlikely to have a significant effect on the European features of

interest.

DRAFT DROUGHT PLAN:


24

The daily Wortham licence is 3.64Ml/d, which equates to 1,329Ml/annum. An

increase in the Redgrave Group annual licence would not increase the annual

abstraction from Wortham borehole, as the additional licensed annual quantity

would be abstracted from Mendlesham, Syleham and Eye boreholes (within

existing daily licence conditions), none of which would have an effect on Chalk

groundwater levels at Redgrave and Lopham Fen.

Consequently, it can be concluded that this drought action would have no

likely significant effects on Redgrave and Lopham Fen’s European features of

Interest.

4.2.3 Stage three: Assessment of Mitigation and Alternatives

This section considers whether there are alternative drought actions that could




Alternatives



increase the Ormesby/Bure annual licence:

Appeals for restraint (1 in 20 Years Level of Service)

Suspension of mains flushing



Tankering

The only other alternative supply-side drought action is the Bedingfield

Drought Action.

Mitigation

No likely significant effects have been identified. However, should increased

abstraction from Eye, Syleham or Mendlesham boreholes give rise to

significant adverse effect, the drought action would be withdrawn unless

Imperative Reasons of Overriding Public Interest (IROPI) is demonstrated.

4.3 Saxmundham Daily Licence


The drought action is an application for a drought permit to increase the daily

licensed quantity of water that can be abstracted from Saxmundham Borehole

DRAFT DROUGHT PLAN:


25

from 0.91Ml/d to 1.2Ml/d, where 1.2Ml/d is the maximum capacity of

Saxmundham Treatment Works.

4.3.2 Environmental Assessment

The Agency’s Review of Consents process assessed the effect of fully

licensed abstraction from ESW’s Little Glemham, Benhall, Parham and

Saxmundham boreholes on the Alde Estuary. It concluded likely significant

effect under existing abstraction licence conditions, because the in-

combination effect of abstraction from these sources can:

reduce Crag groundwater levels; reduce base-flow to the River Alde; and, reduce fresh water flows to the Alde Ore Estuary.

ESW completed an Alde/Ore Options Appraisal to identify how a Minimum

Residual Flow (MRF) to the estuary can always be achieved, as measured at

the RoC assessment point at Farnham gauging station. The agreed solution

is to make a compensation discharge into the River Alde, upstream of the

assessment point, from an existing Benhall TWs borehole. Consequently, it is

possible to conclude no likely significant effects in relation to fully licensed

abstraction under existing licence conditions.

4.3.3 Stage three: Assessment of Mitigation and Alternatives

This section considers whether there are alternative drought actions that could




Alternatives



increase the Saxmundham daily licence:

Appeals for Restraint (1 in 20 Years Level of Service)

Suspension of Mains Flushing



Tankering

The only other drought action to benefit this resource zone, and that can be

considered as an alternative, is the Coldfair Green and Leiston abstraction

licence drought action.

DRAFT DROUGHT PLAN:


26

Neither the Coldfair Green nor Leiston abstractions are likely to have an effect

on a European site (they were not subject to the RoC process).

Consequently, a drought action to increase annual abstraction at these sites

might be considered more favourable to implementation of the Saxmundham

Borehole drought action.

Mitigation

ESW’s RoC solution to make a compensation discharge into the River Alde at

Benhall TWs during drought has now been implemented. This will ensure that

the MRF will be met at all times and following implementation of this drought

action. Consequently, a conclusion of no likely significant effect on the Alde

Ore Estuary can be drawn.

If significant adverse effects were identified, the drought action would be

withdrawn unless Imperative Reasons of Overriding Public Interest (IROPI)

could be demonstrated.

DRAFT DROUGHT PLAN:


27

5 CONCLUSIONS & RECOMMENDATIONS

The Saxmundham borehole, Redgrave group licence and Ormesby/Bure

licence drought action abstraction points have all been identified as being in

close proximity to European sites all of which are likely to be sensitive to

additional abstraction. Consequently, an assessment has been undertaken to

establish whether significant effect is likely.

A conclusion of no likely significant effect for all drought actions has been

drawn. Consequently, this means that an Appropriate Assessment for these

drought actions is not required.

DROUGHT ACTION ENVIRONMENTAL REPORT:

BENHALL GROUP LICENCE

28

6 REFERENCES

Environment Agency (2011) Water Company Drought Plan Guideline

Environment Agency (2016) Water Company Drought Plan Guideline

Environment Agency (May 2016) Drought Plan Guideline Extra Information:

Environmental Assessment for Water Company Drought Plans

Essex & Suffolk Water (2017) Draft Drought Plan, Essex & Suffolk Water

Essex & Suffolk Water (2017) Drought Action Environmental Reports:

Ormesby / Bure Licence: Trinity Broads

Ormesby / Bure Licence: Bure Broads & Marshes

Coldfair Green and Leiston Boreholes

Saxmundham Daily Licence

Redgrave Group Licence

Wortham Compensation Discharge

Lound Annual Licence

Bedingfield Annual Licence

Waveney Augmentation Groundwater Scheme

Stour Augmentation Groundwater Scheme

Sandon Brooke Compensation Discharge

UKWIR (DRAFT 2011) Strategic Environmental Assessment and Habitats

Regulation Assessment of Drought Plans Draft Guidance, Cascade

Consulting

Documents

HABITATS REGULATION ASSESSMENT SCREENING REPORT€¦ · HABITATS REGULATION ASSESSMENT SCREENING REPORT DROUGHT PLAN: ... 4.1 Ormesby / Bure Drought Action ... Reduce / stop compensation