2075 SWMS&FRA Gibraltar Way [Jan18] Final

Client: F.D Attwood & Partners Surface Water Drainage Strategy for the Proposed Development at Gibraltar Way, Chatham, Kent

January 2019

Canterbury Office Unit 6 & 7 Barham Business Park Elham Valley Road Barham Canterbury Kent CT4 6DQ

Tel 01227 833855 London Office 6-8 Bonhill Street London EC2A 4BX www.herringtonconsulting.co.uk

This report has been prepared by Herrington Consulting Ltd in accordance with the instructions of their client, F.D Attwood & Partners for their sole and specific use. Any other persons who use any information contained herein do so at their own risk.

© Herrington Consulting Limited 2019

Client: F.D Attwood & Partners Surface Water Management Strategy for the Proposed Development at Gibraltar Way, Chatham, Kent

Contents Amendment Record This report has been issued and amended as follows:

Issue Revision Description Date

1 0 Draft report issued by email. 28 December 2018

2 1 Draft report reissued by email. Plans and appendices updated

18 January 2019

3 1 Final report issued by email 25 January 2019

4 2 Final report updated with minor text changes

28 January 2019

This page is left intentionally blank

Document Verification

Issue Revision Date: 28 December 2018

1 0 Author(s): Sebastian Bures Sean Robinson

Director Sign Off: Simon Maiden-Brooks

Issue Revision Date: 18 January 2019

2 1 Author(s) Lee Adderley

Checked By: Sebastian Bures


3 1 Author (s) Sebastian Bures

Checked By: Lee Adderley


4 2 Author (s) Sebastian Bures

Checked By: Lee Adderley


Contents Page

1 Scope of Appraisal 1

2 Background Information 2 2.1 Site Location and Existing Use 2 2.2 Site Geology and Topography 2 2.3 Proposed Development 3 2.4 Planning Policy and Context 3 2.5 Climate Change 4

3 Potential Sources of Flooding 6

4 Existing Drainage 8 4.1 Existing Surface Water Drainage 8

5 Management of existing overland flow 9 5.1 Surface Water Flooding 9 5.2 Topographical Survey and Ground Investigations 9 5.3 Catchment Areas 10 5.4 Deluge Model 12 5.5 Flow Path Swale 13

6 Sustainable Drainage Assessment 15 6.1 Opportunities to Discharge Surface Water Runoff 15 6.2 Proposed Surface Water Management Strategy 16 6.3 Management and Maintenance 21 6.4 Sensitivity Testing and Residual Risk 22 6.5 Foul Water Management 23

7 Conclusions and Recommendations 24

8 Appendices


Land at Gibraltar Way, Chatham Surface Water Management Strategy

1

1 Scope of Appraisal

Herrington Consulting Ltd. has been commissioned by F.D Attwood & Partners to prepare a

Surface Water Management Strategy for the proposed development at the following location:

Gibraltar Way, North Dane Way, Chatham ME5 8YE

The objective of this Surface Water Management Strategy is to outline the options for the disposal

of surface water runoff from the proposed development.

This report has been prepared to supplement a full planning application and has been prepared in

accordance with the requirements of both national and local planning policy. To ensure that due

account is taken of industry best practice, reference has also been made to, CIRIA Report C753

‘The SuDS Manual’ and any relevant local planning policy guidance. The surface water

management strategy included within this report is not intended to constitute a detailed drainage

design.


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2 Background Information

2.1 Site Location and Existing Use The site is located at OS coordinates 578052, 162983 at Gibraltar Way in Chatham and covers an

area of approximately 27 hectares. The location of the site in relation to the surrounding area is

shown in Figure 2.1.

Figure 2.1 – Location map (Contains Ordnance Survey data © Crown copyright and database right

2019).

The site currently comprises mostly of greenfield space, with a farm located to the north west of the

site.

2.2 Site Geology and Topography Reference to the British Geological Survey (BGS) data identifies that the geology at the site

comprises two bedrock and two superficial formations. The north corner of the site has a Lewes

Nodular Chalk Formation bedrock, overlaid with a Head superficial deposit. Whereas, the rest of

the site has a Seaford Chalk Formation bedrock, overlaid with a Clay-with-flints Formation

superficial deposits.

Reference to a site-specific topographic survey indicates that land levels at the site vary between

103.9m AODN in the north western part of the site and 131.4m AODN in the southern part of the

site.


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2.3 Proposed Development The development is an outline application and comprise the construction of up to 450 residential

units, a nursery and associated open space and landscaping. Figure 2.2 below shows the proposed

site plan.

Figure 2.2 – Proposed Development Plan.

Further drawings of the proposed scheme are included in Appendix A.1 of this report.

2.4 Planning Policy and Context The general requirement for all new development is to ensure that the runoff from the development

is managed sustainably and that the drainage solution does not increase the risk of flooding at the

site, or within the surrounding area.

For undeveloped greenfield sites, the impact of the proposed development will therefore require

mitigation to ensure that the runoff from the site replicates the natural drainage characteristics of

the pre-developed site. In the case of brownfield sites, drainage proposals are typically measured

against the existing performance of the site, although it is preferable (where practicable) to provide

runoff characteristics that are similar to greenfield behaviour.

In accordance with the Town and Country Planning (Development Management Procedure) Order

2010, the proposals for this site are classified as ‘major’ development and therefore the (non-

statutory) Technical Standards for SuDS (NTSS) will apply and have been referenced to throughout

this report.


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In addition to the NTSS, Chatham is located within the Medway constituency and therefore,

Medway Council is the Lead Local Flood Authority (LLFA). The site is also subject to local

requirements set out within the Medway Strategic Flood Risk Assessment (SFRA), specifically

requiring Sustainable Drainage Systems (SuDS) to be incorporated into all local development.

2.5 Climate Change The global climate is constantly changing, but it is widely recognised that we are now entering a

period of accelerating change. Over the last few decades there have been numerous studies into

the impact of potential futures changes in the climate and there is now an increasing body of

scientific evidence which supports the fact that the global climate is changing as a result of human

activity. Past, present, and future emissions of greenhouse gases are expected to cause significant

global climate change during this century.

The nature of climate change at a regional level will vary: for the UK, projections of future climate

change indicate that more frequent short-duration, high-intensity rainfall, and more frequent periods

of long-duration rainfall (of the type responsible for the recent UK flooding) could be expected.

These effects will tend to increase the size of flood zones associated with rivers, and the amount

of flooding experienced from other inland sources. Consequently, the following section of this report

takes into consideration the impacts of climate change and references the most contemporary

guidance which is applicable to the development site.

To ensure that any recommended mitigation measures are sustainable and effective throughout

the lifetime of the development, it is necessary to base the appraisal on climate change predictions

which are commensurate with the planning horizon for the proposed development. The NPPF and

supporting Planning Practice Guidance Suite state that residential development should be

considered for a minimum of 100 years, but that the lifetime of a non-residential development

depends on the characteristics of the development. The development that is the subject of this

SWMS is classified as residential, and therefore a design life of 100 years has been assumed.

Potential Changes in Climate

The recommended allowances for increases in peak rainfall intensity were updated by the

Environment Agency in February 2016 and are applicable nationally. These allowances, shown in

Table 2.2 below, provides a range of values which correspond with the Central and Upper End

percentiles (i.e. the 50th and 90th percentile respectively) over three-time epochs.


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Allowance Category (applicable nationwide)

Total potential change anticipated for each epoch

2015 to 2039 2040 to 2069 2070 to 2115

Upper End +10% +20% +40%

Central +5% +10% +20%

Table 2.2 – Recommended peak rainfall intensity allowance for small and urban catchments (1961

to 1990 baseline).

For development sites located within Medway, which are particularly vulnerable to flooding as a

result of changes in peak rainfall intensity, the LLFA require the Upper End climate change

allowance to be applied. For developments which are less sensitive (i.e. commercial development)

the lower central allowance may be referenced.


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3 Potential Sources of Flooding

In determining whether the proposals for development are compliant with the NPPF, it is necessary

to determine whether the development will be sustainable in terms of flood risk. A Flood Risk

Assessment has previously been completed (by Others) and this report has been referenced in the

below section. As such, the main sources of flooding have been assessed and are discussed in

Table 3.1 below.

Source of Flooding Evidence

Risk of Flooding from Rivers

The site is situated in Flood Zone 1 and is not located within an area identified by the Environment Agency’s Flood Zone mapping as being at risk of flooding from a fluvial source. Consequently, the risk of flooding from rivers is low.

Risk of Flooding from Sea/Estuaries

The site is located a significant distance inland and is elevated above the predicted extreme tide levels. Consequently, the risk of flooding from this source is low.

Risk of Flooding from Ordinary and man-made watercourses

Inspection of OS mapping of the site and surrounding area reveals that there are no non-main rivers or artificial watercourses within close proximity to the site. Therefore, the risk of flooding from this source is low.

Risk of Flooding from Overland flow

Inspection of the Environment Agency ‘Flood Risk from Surface Water’ mapping identifies that the majority of the site is at ‘very low’ risk of flooding from surface water. The mapping does, however, indicate a surface water flow path crosses the western part of the site from south to north. This flow path is marked as ‘low’ to ‘high’ risk. The risk of flooding to the development from this surface water flow path will be mitigated through the use of SuDS (see Section 5 below). As such, following the implementation of the mitigation measures outlined in this report, the risk of flooding to the development site from surface water is considered to be low.

Risk of Flooding from Groundwater

Groundwater flooding is most likely to occur in low lying areas underlain by permeable rock (aquifers). The underlying geology in this area is Seaford Chalk Formation and Lewes Nodular Chalk Formation. A review of mapping provided as part of the Defra Groundwater Flood Scoping Study (May 2004) shows that no groundwater flooding events were recorded near the site during the very wet periods of 2000/01 or 2002/03. The mapping also identifies that the site itself is not located within an area where groundwater emergence is predicted. Furthermore, reference to the results of site-specific ground investigations (completed by others) identifies that no ground water was encountered within the five 20m deep boreholes carried out at the site. Therefore, taking the above into consideration the risk of flooding to the site from groundwater is considered to be low.


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Table 3.1 – Assessment of the risk of flooding from all sources.

From the analysis in Table 3.1, it can be seen that, following the mitigation measures set out within

this report, the site will not be exposed to any significant risk of flooding.

Source of Flooding Evidence

Risk of Flooding from Sewers

Inspection of the asset location mapping provided by Southern Water identifies that there is a foul water sewer located to the southwest of the site along North Dane Way. The same mapping also identifies that there is a surface water sewer to the west of the site along North Dane Way. Both of these sewers flow away from the site to the northwest following the gradient of the highway and the absence of combined sewers significantly reduces the risk of the network surcharging. This is supported by the historic records within the SFRA which indicate that there have been no recorded incidents of sewer flooding in this location previously. Notwithstanding this, in the unlikely event that water was to exit these sewers (i.e. as a result of a blockage or extreme pluvial event), floodwater is unlikely to be directed towards the site. Instead, floodwater will flow to the northwest within the highway, following the natural topography of the area. Consequently, there is a low risk of flooding to the site from sewers.

Risk of Flooding from Artificial Sources

Inspection of the OS mapping for the area shows that there are no artificial sources of flooding within close proximity to the site. In addition, the Environment Agency’s ‘Flood Risk from Reservoirs’ website shows that the site is not within an area considered to be at risk of flooding from reservoirs. Consequently, the risk of flooding from this source is low.


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4 Existing Drainage

4.1 Existing Surface Water Drainage The existing site is agricultural land and as such, drains informally to the surrounding areas and

infiltrates into the ground. Greenfield runoff rates have been calculated for the existing site using

FEH statistical method and the Wallingford online tool, and have been summarised in Table 4.1

below based on a site area of 27ha.

Return period (years) Peak runoff from the existing site (l/s)

1 43.3

30 117.1

100 162.4

Table 4.1 - Summary of greenfield runoff rates for the existing site.

4.2 Southern Water Assets

An existing foul sewer and surface water sewer is located along North Dane Way, to the south of

the site. Figure 4.1 below is a plan showing the nearest sewers.

Figure 4.1 – Southern Water asset plan.

Site Boundary

Foul Sewer

Surface Water Sewer


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5 Management of Existing Overland Flow

Inspection of the Environment Agency ‘Risk of Flooding from Surface Water’ mapping show that

the site is located within an area identified to be at moderate-high risk of flooding from surface

water. The mapping shows a surface water flow path running through the centre of the proposed

development site from south to north. This section looks at how the existing overland flow path has

been quantified and how it has been incorporated into the final design layout

5.1 Surface Water Flooding A screenshot of the Environment Agency mapping is shown in Figure 5.1 below.

Probability of flooding

High – Extent of flooding from surface water that has a 3.3% (1 in 30) or greater chance of happening each year.

Medium - Extent of flooding from surface water that has between a 3.3% (1 in 30) and 1% (1 in 100) chance of happening each year.

Low - Extent of flooding from surface water that has between a 1% (1 in 100) and 0.1% (1 in 1000) chance of happening each year.

Location of development site

Figure 5.1 – Surface water flood map showing the location of the development site (©

Environment Agency)

The mapping provided by the EA is based on relatively coarse information, designed to provide a

high-level indication of the risk of flooding to a site on a national scale. The mapping does not take

into consideration the localised site-specific topography or geology, and the maps do not include

an allowance for climate change, as is required by the NPPF. Consequently, to more accurately

quantify the potential depth and extent of flooding following an extreme pluvial event, a deluge

model of the catchment has been constructed. The methodology for constructing the model and

the results predicted by the model for the design rainfall event, are discussed further in this section.

5.2 Topographical Survey and Ground Investigations The site-specific topographical survey identifies a dry valley running through the north eastern

section of the site. Figure 5.2 below identifies the current topography and land contours.


10

Table 5.2 – Site topography with the dry valley indicated by red shape.

When comparing Figure 5.1 to the image above, it is evident that the dry valley closely represents

the geographical shape shown in Figure 5.2.

Although the feature appears sizable, there are no indications of any wet features on site, such as

ditches and wetlands. Site specific investigations for the site indicate that the groundwater levels

are below 20m BGL, which suggests that this feature is historic.

Site investigations also indicate that the ground is relatively permeable due to the underlying

Seaford chalk. This would suggest significant ground saturation would need to occur for above

ground surface water flooding to be present. Nonetheless, a deluge model has been built to quantify

surface water flooding in the event that the ground is fully saturated.

5.3 Catchment Areas The full catchment area for the site has been obtained from the Flood Estimation Handbook (FEH)

catchment web-service, and this indicates the full extent of the catchment covering most of the

Lords Woods estate up to the A2045


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Figure 5.3 – Full FEH catchment.

From site visits of the urban extent, it is acknowledged that the impermeable areas are drained

separately and directed away from the total catchment in a dedicated drainage network.

Consequently, the total contributing catchment area has been adjusted taking into consideration

the (drained) urbanised extent.

Taking the above into consideration, the amended catchment area has been adjusted and is shown

in Figure 5.4 below. LiDAR data has been overlaid on top of the catchment and surrounding area

to establish the ground contours.


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Figure 5.4 – Adjusted contributing catchment area.

5.4 Deluge Model A deluge model has been constructed by exporting the level data from the contributing catchment

area (shown in Figure 5.4) and applying 61mm of rainfall over the entire catchment. The depth of

61mm has been calculated using the growth chart for a pluvial event with a 1 in 100 year return

period.


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Figure 5.5 – Deluge model of rainfall applied over catchment area.

The deluge model indicates 3 areas on site which have the potential to allow surface water runoff

to pond, should the ground become fully saturated. Area A indicates a flow path within the dry

valley, and the maximum flow rate at this location is estimated to be approximately 1,500 l/s (running

directly through the site). Area B indicates an area ponding adjacent to Gibraltar Cottages, and

Area C indicates an area of ponding located just outside of the site area to the north east of the

site.

In order to mitigate the risk of surface water flooding, these areas have been incorporated into the

development layout. The dry valley running through the site (Area A) has been incorporated into a

proposed swale and is discussed further below.

5.5 Flow Path Swale To ensure that the identified flow path is incorporated into the development site, a green corridor is

proposed to run through the site. This area will not contain any residential units. The green corridor

will provide allow a minimum of 1,500 l/s to pass through the site unimpeded, thus maintaining the

natural flow path through the site. Given the permeability of area it is considered unlikely that this

flow path will be visible even during the design event. Notwithstanding this, by adopting this

A B

C


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conservative approach when developing the site layout it is possible to minimise the risk to the

development of above ground flooding and it will help to maintain any natural overland flow path.


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6 Sustainable Drainage Assessment

6.1 Opportunities to Discharge Surface Water Runoff Part H of the Building Regulations summarises a hierarchy of options for discharging surface water

runoff from developments. The most preferential option is to infiltrate water into the ground, as this

deals with the water at source and serves to replenish groundwater. If this option is not viable, the

next option of preference is for the runoff to be discharged into a watercourse. Only if neither of

these options are possible, the water should be conducted into the public sewer system.

For some sites it is recognised that under periods of high rainfall intensity, or long duration rainfall

events, the saturated ground can lead to insufficient porosity, thus preventing surface water runoff

from infiltrating into the ground. In these cases, a joint solution termed by CIRIA C753 as ‘Type B

SuDS’ is often used. This approach combines infiltration with attenuation to maximise discharge at

source, whilst simultaneously ensuring any runoff which is not infiltrated into the ground can instead

be restricted to greenfield runoff rates.

The following opportunities for managing the surface water runoff discharged from the development

site are listed in order of preference:

Water Re-use – Water re-use systems can rarely manage 100% of the surface water runoff

discharged from a development, as this requires the yield from the building and hardstanding area

to balance perfectly with the demand from the proposed development. Consequently, whilst

rainwater recycling systems can be considered for inclusion within the scheme, an alternative

solution for attenuating storm water will still be required.

Infiltration – Geotechnical Investigations produced by Ground Technology Services (included

within Appendix A.2), indicate that the site is located within the Seaford Chalk Formation and the

Lewes Nodular Chalk Formation. BRE 365 infiltration testing has been undertaken across the site

and the results show good soakage rates (between 0.256 and 3.78m/hr). Consequently, on this

basis, infiltration will be a suitable method for discharging surface water runoff from the site.

Discharge to Watercourses – There are no watercourses located within close proximity to the site

which show onward connectivity to a main river, the sea, or any other large surface water body. As

a result, there is no opportunity to discharge surface water runoff from the development to an

existing watercourse.

Discharge to Public Sewer System – With a preferable solution available to manage the surface

water discharged from the development, a connection to the public sewer system is unlikely to be

required.


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Nevertheless, in the event that the option to use infiltration is found to be restricted at the detailed

design stage, there is a Southern Water (surface water) sewer located along North Dane Way which

could be considered as a viable alternative.

6.2 Proposed Surface Water Management Strategy The drainage strategy set out below discusses each element of the proposed scheme, along with

calculations that have been undertaken to demonstrate how the overall objectives can be achieved.

This does not represent a detailed surface water drainage design; it is simply an assessment to

demonstrate that the objectives and requirements of the NPPF can be met at the planning stage.

Due to the scale of the development, the drainage systems have been split between 6 discrete

catchment areas, defined using the existing site topography. These sub-catchments can be seen

in Figure 6.1 below.

Figure 6.1 – Plan showing drainage sub-catchment areas for the properties.

A B

C D

E

E

F

DB1

DB2

DB3

DB4

DB6

DB5

B


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Water Butts

To reduce the developments reliance on potable water supplies for external use there is the

potential to incorporate water butts within the communal garden area. Typical sizes and dimensions

of water butts are outlined below.

Typical house water butt options Dimensions of a typical house water butt

Volume of storage provided (litres)

Type 1 (wall mounted – Small) 1.22m high x 0.46m x 0.23m 100

Type 2 (Standard house water butt) 0.9m high x 0.68m diameter 210

Type 3 (Large house water butt) 1.26m high x 1.24m x 0.8m 510

Type 4 (Column tank – Very large) 2.23m high x 1.28m diameter 2000

Table 6.1 – Estimated storage capacity of available water butts.

Most of the properties have gardens and therefore, present the option to include a water butt. It is

recognised that each of the water butts will need to overflow into the main drainage system for the

site, to ensure that in the event the water butt is full prior to the onset of the design rainfall event,

water can be discharged away from the properties without increasing the risk of flooding.

Permeable Paving Driveways

Surface water falling on the driveways of the residential units will be directed into the permeable

paving systems, located on each driveway. The underlying granular sub-base of each driveway will

be used to attenuate surface water runoff and infiltrate water into the ground. It is recommended

that the depth of sub-base beneath the permeable paving is specified to be a minimum of 450mm

deep, which will help to enhance the water quality benefits.

An overflow from each property will need to be installed with onward connectivity to the drainage

basins. The overflow will be connected into the combined residential drainage system which will

include surface water runoff from the units without driveways. The system will discharge into the

series of drainage basins located across the site (discussed further below).

Highway Drainage and Permeable Surface

Surface water runoff from the main through roads will be drained into a series of road gullies with

catch pits, designed to collect sediment. Water will be conveyed across the site and discharged

into the residential roads. The residential roads and car park areas will be constructed of a

permeable surface with an open graded sub-base layer. The sub-base layer will provide water

quality treatment benefits and subsurface attenuation storage, before infiltrating into the underlying

ground.

It is recognised that it will be necessary to ensure that the sub-base is constructed within the chalk

layer to ensure appropriate infiltration. Where the roads are sloped across the site, it will also be

necessary to install a series of check-dams to maximise the storage capacity within the sub-base.


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Figure 6.2 below shows where there is potential to install permeable surfacing within the residential

roads and car parking areas. The plan also indicates approximate sub-catchment areas which have

been used within the calculations below.

Figure 6.2 – Plan showing areas suitable for permeable surfacing. The design parameters for the permeable surfacing system is summarised in the table below. The

calculations have been referenced based on approximate positions of the permeable surfacing and

are referenced to in Figure 6.2 above.

Parameter Value (1:100yr+30%cc event)

SuDS Permeable Paving

Sub-base depth 500 mm

Infiltration 0.256 m/hr

Sub-grade porosity 0.3

Table 6.2 – Summary of the permeable surfacing design.

A summary of the Micro Drainage analysis for permeable surfacing is shown in Table 6.2 below.

1

2

5

4

3


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Catchment Total area draining to catchment

Total area of permeable surface Half Drain time

Catchment 1 (PP1) 5,540m2 3,861m2 79 minutes





Table 6.3 – Summary of Micro Drainage calculations for 1:100 yr + 30% climate change.

It is evident that, with the inclusion of the proposed SuDS, there is the potential to accommodate

all the surface water runoff from the highway and car park areas up to, and including, the design

rainfall event.

Landscaped Swales

Catchments C and D will have landscaped areas which will be used to convey surface water runoff

towards the proposed detention basins. Surface water runoff from the residential roofs will be

diverted into the landscaped areas, maximising potential for water to be absorbed and treated,

before discharging to the drainage basins.

Figure 6.3 below shows the location of these areas, highlighted in dark green.


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Figure 6.3 – Landscaped areas suitable for conveying surface water. Drainage Basins

Surface water runoff discharged from the roof areas will drain into a number of detention basins,

located across the site. These drainage basins will consist of vegetated depressions in the

landscape, which will be used to attenuate and infiltrate storm water. The location of the proposed

drainage basins can be seen in Figure 6.3 above. The attenuated volumes have been estimated to

provide 300mm float from each feature and assuming infiltration through the base only, into the

underlying chalk.

The design parameters for the drainage basins is summarised in Table 6.4 below.


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Parameter Value (1:100yr+30%cc event)

SuDS method Drainage Basin

Proposed depth of basin 1.5m BGL

Infiltration rate 0.256 m/hr

Basin Identity DB 1 DB 2 DB 3 DB 4 DB 5 DB 6

Estimated impermeable area draining to basin 8,950m² 7,120m² 3,040m² 7,650m² 7,800m² 3,540m²

Total storage volume 1,032 m³ 803 m³ 350 m³ 882 m³ 990 m³ 412 m³

Half drain times (minutes) 1,354 1,371 1,362 1,343 1,414 1,351

Table 6.4 – Summary of the Micro Drainage Results for the Drainage Basins.

From the table above and Table 6.3, it can be seen that the proposed drainage system can manage

the runoff from the entire development through infiltration, thereby limiting the amount of surface

water runoff discharged offsite.

Indicative Drainage Layout Plans

The proposed plans showing the indicative drainage layout and delineating how the proposed SuDS

can be incorporated into the proposed scheme is included within Appendix A.3 of this report.

6.3 Management and Maintenance For any surface water drainage system to operate as originally designed, it is necessary to ensure

that it is adequately maintained throughout its lifetime.

The key requirements of any management regime are routine inspection and maintenance, when

the development is taken forward to the detailed design stage an ‘owner’s manual’ will need to be

prepared. This should include:

• A description of the drainage scheme,

• A location plan showing all of the SuDS features and equipment such as flow control

devices etc.

• Maintenance requirements for each element, including any manufacturer specific

requirements

• An explanation of the consequences of not carrying out the specified maintenance

• Details of who will be responsible for the ongoing maintenance of the drainage system.


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For the SuDS recommended by this assessment, the most obvious maintenance tasks will be the

regular brushing and cleaning of the permeable surfacing and the pruning of vegetation across the

site. Typical maintenance requirements of each of the proposed SuDS is included within Appendix

A.5.

For developments such as this that rely to some extent on the ongoing inspection and maintenance

of SuDS, it will be necessary to ensure that measures are in place to maintain the system for the

lifetime of the development.

For the communal SuDS including the permeable surfacing system and drainage basins, it is likely

that the management company responsible for maintaining the rest of the site will be tasked with

the inspection and maintenance of these features. In addition, the regular inspection and desilting

of the manholes will need to be carried out.

For the SuDS located within the private garden areas, it is likely that maintenance will be the

responsibility of the individual property owners / occupants. In this case maintenance tasks are

likely to include desilting of the water butts.

Further details of the maintenance and management strategy should be confirmed following the

completion of a detailed drainage design for the development.

6.4 Sensitivity Testing and Residual Risk When considering residual risk, it is necessary to consider the impact of a flood event that exceeds

the design event, or the implications if the proposed drainage system becomes blocked.

The proposed drainage system has been designed for an extreme rainfall event with a return period

of 1 in 100 years, including a 30% increase in peak rainfall intensity (to account for the impacts of

climate change). Nonetheless, based on the EA’s most contemporary climate change guidance an

Upper End climate change allowance of 40% has been used to test the proposed drainage system

to reflect further increases in peak rainfall intensity.

Calculations have been undertaken to assess the performance of the drainage system under the

design rainfall event, including a 40% increase in peak rainfall intensity due to climate change.

These calculations can be found within Appendix A.4.

The calculations for the permeable paving and drainage basin show that the proposed drainage

systems are not susceptible to increases in peak rainfall intensity and as such, the system does not

flood. This is due to the storage features having additional (spare) capacity.

Inspection of the topography across the site suggests that if the permeable paving was to block, or

become overwhelmed following an extreme rainfall event, water could exit the permeable paving

and flow northwards. Where this is not possible, local ponding may occur. It is recommended that

kerbs are installed on the road network to contain any flood water resulting in a blockage, or as the

result of an exceedance event.


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It should be recognised that the drainage proposals will incorporate a significant volume of

additional storage for storm water, which is not currently provided for on the existing site. As a

result, when compared to the existing site, it is evident that the volume of water discharged from

the site during an extreme rainfall event is likely to be reduced, thus minimising the potential impact

of flooding to the surrounding area.

6.5 Foul Water Management Southern Water has been consulted (by others) under a level 2 enquiry. A copy of the Southern

Water response has been provided in Appendix A.6 of this report.

It will be necessary to install a foul pumping station at the site in the north western corner of the

development, with a direct connection to the Southern Water network.

Southern Water have advised that additional sewer network upgrades will be required if a local

connection is required, or alternatively a direct connection could be made approximately 1,800m

Northwest of the proposed development site.

The response indicates that there is potential to accommodate foul water from the proposed

development providing adequate network infrastructure is put in place as part of the development.

It is recommended Southern Water are consulted further at detailed design to agree the route of

discharge.


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7 Conclusions and Recommendations

The overarching objective of this report is to appraise the proposals for the development at Gibraltar

Way, Chatham to ensure that the risk of flooding to the occupants of the proposed residential units

is acceptable and that the risk of flooding offsite will not increase as a result of the development

proposals. This report has therefore been prepared to appraise the risk of flooding from all sources

and to provide a sustainable solution for managing the surface water runoff discharged from the

development site, in accordance with the NPPF and local planning policy.

The risk of flooding has been considered for a wide range of sources and it has been identified that

the risk of flooding to the proposed development is low, with the exception to surface water. Where

there is an increased risk of surface water flooding, this risk has been quantified and measures

have been included as part of the development to mitigate the risk. The mitigation measures

comprise a ‘green corridor’ through the residential units, allowing surface water to follow its natural

route through the site.

In order to minimise the impact that the buildings could have with respect to an increase is surface

water runoff, the opportunities for managing surface water at the site have been further analysed.

It is concluded that the most viable solution for managing all of the surface water runoff discharged

from the proposed development will be via infiltration into the ground.

To restrict the rate at which surface water runoff is discharged offsite, various SuDS have been

proposed, including; water butts, swales, permeable paving and drainage basins. These SuDS will

be used to store water onsite and maximise the water which can be adsorbed by vegetation and

infiltrated into the ground. The permeable paving and drainage basins provide storage on site,

allowing water to be stored during rainfall events with longer return periods. This approach

replicates the greenfield conditions and is in accordance with the NTSS.

Details of the typical maintenance and management requirements for each element of the drainage

system have been provided to ensure that the proposed drainage solution can be maintained and

will continue to operate in perpetuity. It is, however, recommended that an “owner’s manual”

containing additional product specific maintenance requirements is produced as part of the detailed

design for the site.

In conclusion, it is evident that the development is at low risk of flooding and a sustainable solution

for managing the surface water runoff discharged from the proposed development at Gibraltar Way

is available. Consequently, the proposals will meet the requirements of the NPPF and local planning

policy.


Appendices

8 Appendices

Appendix A.1 – Drawings

Appendix A.2 – Site Investigation Results

Appendix A.3 – Indicative Drainage Layout Plans

Appendix A.4 – Surface Water Management Calculations

Appendix A.5 – Maintenance Schedules

Appendix A.6 – Foul Enquiry (Extract from report Ref GL/HB/P14-630/03)


Appendices

Appendix A.1 –Drawings

1.1

3.7

3.7

3.7

3.7

VV

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

SWALE

V

V

V

V

V

V

V

V

BUS STOP

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

R

C

2

9

F

o

o

t

P

a

t

h

16

6

14

14

5a

41

1

ROAD

53

14

45

29

25

18

6

5

KIR

KDAL

E C

LOSE

27

WAVERLEY CLOSE

12

40

20

MAYFORD

45

15

1

46

24

Path (um)

42

40

28

14

29

18

51

2a

72

30

Hall Wood Business Park

12

FARLEY CLOSE

MILLFIELDS

70

11

21

3

33

1

56

6

38

12

19

55

WH

EATF

IELD

S

30

76a

FARL

EY C

LOSE

12

47

12

57

23

3

1

18

5

11

15

El Sub Sta

30

7

44

65

HAYFIELDS

43

24

11

118.1m

23

7

Hall Wood

12

20

33

14

17

22

3

29

27

37

29

2

1

35

43

36

32

67

9

7

29

Path (um)

Hall Wood

Gibraltar

The Granary

Track

Tank

Farm

36

NORTH DANE WAY

104.8m

Playground

Path (um)

Co C

onst

& U

A Bd

y

Path (um)

Und

Def

Path (um)

Def

107.0m

CA

PS

TON

E

Elm Court

115.8m

Area

109.7m

2

Play

LB

112.2m

115.5m

Path (um)

113.4m

Co Const & UA Bdy

1

HAM LANE

Bor

o C

onst

Bdy

Elm Court Village

116.1m

Boro Const & UA Bdy

ROADSR

112.2m

HAM LANE

Gibralt

ar Cott

ages

Indoor

Co

Con

st &

War

d B

dy

LIDSING

CR

Co Const Bdy

111.9m

115.1m

114.6m

18

4

7

5

3

4

40

1

FARL

EY C

LOSE

33

3

17

FARLEY CLOSE

23

75

43

9

70

34

CLO

SE

78

76

41

12

28

14

7

11

47

12

12

18

14

10

El Sub Sta

1

37

70

2

17

22

62

64

10

62a

72

8

1

37

14

23

1

50

14

29

85

31

36

30

1

4

30

11

8

21

25

19

2422

14

HAYFIELDS2a

15

WAVERLEY CLOSE

38

2

BENTLEY

57

31

4

1

7

16

6

PIRB

RIG

HT C

LOSE

15

1

49

42

20

30

41

COM

PTO

N CL

OSE

11

29

17

5

19

12

34

24

2

23

12

1

56

26

11

2

9

15

11

3

1

27

12

17

1

45

7

11

33

15

15

33

1

43

LAD

YFIE

LDS

32

11

CLAN

DON

ROAD

6

15

7

31

619

24

59

70a

11

11

9

El

TATLER CLOSE

2

Sub Sta

71

72

2

17

5

39

2

48

7

67

77

27

1

3

14

76a

15

27

25

RUDG

E CL

OSE

36

V

V

V

V

V

V

V

V

V

V

V

V

VV

VV

V

V

V

V

V

V

V

V

V

V

V

VVV

V

VV

VV

V V

V

V

V

V

V

V

V

V V

V

V

V

V

V

V

V

V V

V V V V

V

V

V

V

Nursery

Play areafor nursery

V

V

V

V

V

V

V

Nursery


16

6

14

14

5a

41

1

ROAD

53

14

45

29

25

18

6

5

KIR

KDAL

E C

LOSE

27

WAVERLEY CLOSE

12

40

20

MAYFORD

45

15

1

46

24

Path (um)

42

40

28

14

29

18

51

2a

72

30


12

FARLEY CLOSE

MILLFIELDS

70

11

21

3

33

1

56

6

38

12

19

55

WH

EATF

IELD

S

30

76a

FARL

EY C

LOSE

12

47

12

57

23

3

1

18

5

11

15

El Sub Sta

30

7

44

65

HAYFIELDS

43

24

11

118.1m

23

7

Hall Wood

12

20

33

14

17

22

3

29

27

37

29

2

1

35

43

36

32

67

9

7

29

Path (um)

Hall Wood

Gibraltar

The Granary

Track

Tank

Farm

36

NORTH DANE WAY

104.8m

Playground

Path (um)

Co C

onst

& U

A Bd

y

Path (um)

Und

Def

Path (um)

Def

107.0m

CA

PS

TON

E

Elm Court

115.8m

Area

109.7m

2

Play

LB

112.2m

115.5m

Path (um)

113.4m

Co Const & UA Bdy

1

HAM LANE

Bor

o C

onst

Bdy

Elm Court Village

116.1m

Boro Const & UA Bdy

ROADSR

112.2m

HAM LANE

Gibralt

ar Cott

ages

Indoor

Co

Con

st &

War

d B

dy

LIDSING

CR

Co Const Bdy

111.9m

115.1m

114.6m

18

4

7

5

3

4

40

1

FARL

EY C

LOSE

33

3

17

FARLEY CLOSE

23

75

43

9

70

34

CLO

SE

78

76

41

12

28

14

7

11

47

12

12

18

14

10

El Sub Sta

1

37

70

2

17

22

62

64

10

62a

72

8

1

37

14

23

1

50

14

29

85

31

36

30

1

4

30

11

8

21

25

19

2422

14

HAYFIELDS2a

15

WAVERLEY CLOSE

38

2

BENTLEY

57

31

4

1

7

16

6

PIRB

RIG

HT C

LOSE

15

1

49

42

20

30

41

COM

PTO

N CL

OSE

11

29

17

5

19

12

34

24

2

23

12

1

56

26

11

2

9

15

11

3

1

27

12

17

1

45

7

11

33

15

15

33

1

43

LAD

YFIE

LDS

32

11

CLAN

DON

ROAD

6

15

7

31

619

24

59

70a

11

11

9

El

TATLER CLOSE

2

Sub Sta

71

72

2

17

5

39

2

48

7

67

77

27

1

3

14

76a

15

27

25

RUDG

E CL

OSE

36

16

6

14

14

5a

41

1

ROAD

53

14

45

29

25

18

6

5

KIR

KDAL

E C

LOSE

27

WAVERLEY CLOSE

12

40

20

MAYFORD

45

15

1

46

24

Path (um)

42

40

28

14

29

18

51

2a

72

30


12

FARLEY CLOSE

MILLFIELDS

70

11

21

3

33

1

56

6

38

12

19

55

WH

EATF

IELD

S

30

76a

FARL

EY C

LOSE

12

47

12

57

23

3

1

18

5

11

15

El Sub Sta

30

7

44

65

HAYFIELDS

43

24

11

118.1m

23

7

Hall Wood

12

20

33

14

17

22

3

29

27

37

29

2

1

35

43

36

32

67

9

7

29

Path (um)

Hall Wood

Gibraltar

The Granary

Track

Tank

Farm

36

NORTH DANE WAY

104.8m

Playground

Path (um)

Co C

onst

& U

A Bd

y

Path (um)

Und

Def

Path (um)

Def

107.0m

CA

PS

TON

E

Elm Court

115.8m

Area

109.7m

2

Play

LB

112.2m

115.5m

Path (um)

113.4m

Co Const & UA Bdy

1

HAM LANE

Bor

o C

onst

Bdy

Elm Court Village

116.1m

Boro Const & UA Bdy

ROADSR

112.2m

HAM LANE

Gibralt

ar Cott

ages

Indoor

Co

Con

st &

War

d B

dy

LIDSING

CR

Co Const Bdy

111.9m

115.1m

114.6m

18

4

7

5

3

4

40

1

FARL

EY C

LOSE

33

3

17

FARLEY CLOSE

23

75

43

9

70

34

CLO

SE

78

76

41

12

28

14

7

11

47

12

12

18

14

10

El Sub Sta

1

37

70

2

17

22

62

64

10

62a

72

8

1

37

14

23

1

50

14

29

85

31

36

30

1

4

30

11

8

21

25

19

2422

14

HAYFIELDS2a

15

WAVERLEY CLOSE

38

2

BENTLEY

57

31

4

1

7

16

6

PIRB

RIG

HT C

LOSE

15

1

49

42

20

30

41

COM

PTO

N CL

OSE

11

29

17

5

19

12

34

24

2

23

12

1

56

26

11

2

9

15

11

3

1

27

12

17

1

45

7

11

33

15

15

33

1

43

LAD

YFIE

LDS

32

11

CLAN

DON

ROAD

6

15

7

31

619

24

59

70a

11

11

9

El

TATLER CLOSE

2

Sub Sta

71

72

2

17

5

39

2

48

7

67

77

27

1

3

14

76a

15

27

25

RUDG

E CL

OSE

36

1.1

3.7

3.7

3.7

3.7

VV

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

SWALE

V

V

V

V

V

V

V

V

BUS STOP

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

R

C

2

9

F

o

o

t

P

a

t

h

16

6

14

14

5a

41

1

ROAD

53

14

45

29

25

18

6

5

KIR

KDAL

E C

LOSE

27

WAVERLEY CLOSE

12

40

20

MAYFORD

45

15

1

46

24

Path (um)

42

40

28

14

29

18

51

2a

72

30


12

FARLEY CLOSE

MILLFIELDS

70

11

21

3

33

1

56

6

38

12

19

55

WH

EATF

IELD

S

30

76a

FARL

EY C

LOSE

12

47

12

57

23

3

1

18

5

11

15

El Sub Sta

30

7

44

65

HAYFIELDS

43

24

11

118.1m

23

7

Hall Wood

12

20

33

14

17

22

3

29

27

37

29

2

1

35

43

36

32

67

9

7

29

Path (um)

Hall Wood

Gibraltar

The Granary

Track

Tank

Farm

36

NORTH DANE WAY

104.8m

Playground

Path (um)

Co C

onst

& U

A Bd

y

Path (um)

Und

Def

Path (um)

Def

107.0m

CA

PS

TON

E

Elm Court

115.8m

Area

109.7m

2

Play

LB

112.2m

115.5m

Path (um)

113.4m

Co Const & UA Bdy

1

HAM LANE

Bor

o C

onst

Bdy

Elm Court Village

116.1m

Boro Const & UA Bdy

ROADSR

112.2m

HAM LANE

Gibralt

ar Cott

ages

Indoor

Co

Con

st &

War

d B

dy

LIDSING

CR

Co Const Bdy

111.9m

115.1m

114.6m

18

4

7

5

3

4

40

1

FARL

EY C

LOSE

33

3

17

FARLEY CLOSE

23

75

43

9

70

34

CLO

SE

78

76

41

12

28

14

7

11

47

12

12

18

14

10

El Sub Sta

1

37

70

2

17

22

62

64

10

62a

72

8

1

37

14

23

1

50

14

29

85

31

36

30

1

4

30

11

8

21

25

19

2422

14

HAYFIELDS2a

15

WAVERLEY CLOSE

38

2

BENTLEY

57

31

4

1

7

16

6

PIRB

RIG

HT C

LOSE

15

1

49

42

20

30

41

COM

PTO

N CL

OSE

11

29

17

5

19

12

34

24

2

23

12

1

56

26

11

2

9

15

11

3

1

27

12

17

1

45

7

11

33

15

15

33

1

43

LAD

YFIE

LDS

32

11

CLAN

DON

ROAD

6

15

7

31

619

24

59

70a

11

11

9

El

TATLER CLOSE

2

Sub Sta

71

72

2

17

5

39

2

48

7

67

77

27

1

3

14

76a

15

27

25

RUDG

E CL

OSE

36

V

V

V

V

V

V

V

V

V

V

V

V

VV

VV

V

V

V

V

V

V

V

V

V

V

V

VVV

V

VV

VV

V V

V

V

V

V

V

V

V

V V

V

V

V

V

V

V

V

V V

V V V V

V

V

V

V

Nursery


V

V

V

V

V

V

V

Nursery


16

6

14

14

5a

41

1

ROAD

53

14

45

29

25

18

6

5

KIR

KDAL

E C

LOSE

27

WAVERLEY CLOSE

12

40

20

MAYFORD

45

15

1

46

24

Path (um)

42

40

28

14

29

18

51

2a

72

30


12

FARLEY CLOSE

MILLFIELDS

70

11

21

3

33

1

56

6

38

12

19

55

WH

EATF

IELD

S

30

76a

FARL

EY C

LOSE

12

47

12

57

23

3

1

18

5

11

15

El Sub Sta

30

7

44

65

HAYFIELDS

43

24

11

118.1m

23

7

Hall Wood

12

20

33

14

17

22

3

29

27

37

29

2

1

35

43

36

32

67

9

7

29

Path (um)

Hall Wood

Gibraltar

The Granary

Track

Tank

Farm

36

NORTH DANE WAY

104.8m

Playground

Path (um)

Co C

onst

& U

A Bd

y

Path (um)

Und

Def

Path (um)

Def

107.0m

CA

PS

TON

E

Elm Court

115.8m

Area

109.7m

2

Play

LB

112.2m

115.5m

Path (um)

113.4m

Co Const & UA Bdy

1

HAM LANE

Bor

o C

onst

Bdy

Elm Court Village

116.1m

Boro Const & UA Bdy

ROADSR

112.2m

HAM LANE

Gibralt

ar Cott

ages

Indoor

Co

Con

st &

War

d B

dy

LIDSING

CR

Co Const Bdy

111.9m

115.1m

114.6m

18

4

7

5

3

4

40

1

FARL

EY C

LOSE

33

3

17

FARLEY CLOSE

23

75

43

9

70

34

CLO

SE

78

76

41

12

28

14

7

11

47

12

12

18

14

10

El Sub Sta

1

37

70

2

17

22

62

64

10

62a

72

8

1

37

14

23

1

50

14

29

85

31

36

30

1

4

30

11

8

21

25

19

2422

14

HAYFIELDS2a

15

WAVERLEY CLOSE

38

2

BENTLEY

57

31

4

1

7

16

6

PIRB

RIG

HT C

LOSE

15

1

49

42

20

30

41

COM

PTO

N CL

OSE

11

29

17

5

19

12

34

24

2

23

12

1

56

26

11

2

9

15

11

3

1

27

12

17

1

45

7

11

33

15

15

33

1

43

LAD

YFIE

LDS

32

11

CLAN

DON

ROAD

6

15

7

31

619

24

59

70a

11

11

9

El

TATLER CLOSE

2

Sub Sta

71

72

2

17

5

39

2

48

7

67

77

27

1

3

14

76a

15

27

25

RUDG

E CL

OSE

36

16

6

14

14

5a

41

1

ROAD

53

14

45

29

25

18

6

5

KIR

KDAL

E C

LOSE

27

WAVERLEY CLOSE

12

40

20

MAYFORD

45

15

1

46

24

Path (um)

42

40

28

14

29

18

51

2a

72

30


12

FARLEY CLOSE

MILLFIELDS

70

11

21

3

33

1

56

6

38

12

19

55

WH

EATF

IELD

S

30

76a

FARL

EY C

LOSE

12

47

12

57

23

3

1

18

5

11

15

El Sub Sta

30

7

44

65

HAYFIELDS

43

24

11

118.1m

23

7

Hall Wood

12

20

33

14

17

22

3

29

27

37

29

2

1

35

43

36

32

67

9

7

29

Path (um)

Hall Wood

Gibraltar

The Granary

Track

Tank

Farm

36

NORTH DANE WAY

104.8m

Playground

Path (um)

Co C

onst

& U

A Bd

y

Path (um)

Und

Def

Path (um)

Def

107.0m

CA

PS

TON

E

Elm Court

115.8m

Area

109.7m

2

Play

LB

112.2m

115.5m

Path (um)

113.4m

Co Const & UA Bdy

1

HAM LANE

Bor

o C

onst

Bdy

Elm Court Village

116.1m

Boro Const & UA Bdy

ROADSR

112.2m

HAM LANE

Gibralt

ar Cott

ages

Indoor

Co

Con

st &

War

d B

dy

LIDSING

CR

Co Const Bdy

111.9m

115.1m

114.6m

18

4

7

5

3

4

40

1

FARL

EY C

LOSE

33

3

17

FARLEY CLOSE

23

75

43

9

70

34

CLO

SE

78

76

41

12

28

14

7

11

47

12

12

18

14

10

El Sub Sta

1

37

70

2

17

22

62

64

10

62a

72

8

1

37

14

23

1

50

14

29

85

31

36

30

1

4

30

11

8

21

25

19

2422

14

HAYFIELDS2a

15

WAVERLEY CLOSE

38

2

BENTLEY

57

31

4

1

7

16

6

PIRB

RIG

HT C

LOSE

15

1

49

42

20

30

41

COM

PTO

N CL

OSE

11

29

17

5

19

12

34

24

2

23

12

1

56

26

11

2

9

15

11

3

1

27

12

17

1

45

7

11

33

15

15

33

1

43

LAD

YFIE

LDS

32

11

CLAN

DON

ROAD

6

15

7

31

619

24

59

70a

11

11

9

El

TATLER CLOSE

2

Sub Sta

71

72

2

17

5

39

2

48

7

67

77

27

1

3

14

76a

15

27

25

RUDG

E CL

OSE

36

0 20 40 m20 m

Scale 1:1000

REV. DATE DRN. CKD. NOTES

B 08.05.18 SB NLE Site Plan updated to reflect trackingfrom Civil Engineer

Lee Evans Partnership LLP own the copyright of this and any associated

documents. Such documents may not be used or reproduced for any

purpose other than that for which they were created.

z DO NOT SCALE DRAWING

DRAWING NUMBER

DRAWING TITLE

PROJECT

chartered architects

ISSUE STATUS

REVISION

DRN + CKD

SCALE

DATECLIENT

Lee Evans Partnership LLP,

Canterbury: St Johns Lane, Canterbury, Kent CT1 2QQ Tel: 01227 784444

email: [email protected] website: www.lee-evans.co.uk fax: 01227 819102

and planning consultants

@ A0

London: 31-35 Kirby Street, London EC1N 8TE Tel: 0207 492 1744

08418-A-L-(00)-0203

1:1000

21/01/2019

Proposed Site Plan

Kevin Attwood

Gibraltar Farm, Lordswood, Medway : housing

X

N

F 05.10.18 SB NLE Site Plan updated to reflect trackingfrom Civil Engineer

J 05.11.18 SB NLE Footpaths removed from Ancient Woodland

K 06.11.18 SB NLE Site plan adjusted to 15m bufferzone to Hook Wood Ancient Woodland

L 07.11.18 SB NLE West area adjusted to respect Hook Wood Ancient Woodland

M 15.11.18 SB NLE Outline Planning

N 21.11.18 SB NLE Outline Planning

P 22.11.18 SB NLE Outline Planning

Q 22.11.18 SB NLE Outline Planning

R 22.11.18 SB NLE Outline Planning

S 12.12.18 SB NLE Outline Planning

T 18.12.18 NP NLE Outline Planning

U 20.12.18 NP NLE Red line boundary amended

V 04.01.19 NP NLE Red line boundary amended

W 09.01.19 NP NLE Red line boundary amended

X 21.01.19 NP NLE Planting added to NE junction

Documents

2075 SWMS&FRA Gibraltar Way [Jan18] Final