Flood Risk Assessment & Drainage Strategy

FLOOD RISK ASSESSMENT & DRAINAGE STRATEGY CIVIC ENGINEERS December 2020

Civic Engineers

Job Title Prepared for Love Wolverton Agora, Milton Keynes Love Wolverton Limited

Report Type Date Flood Risk Assessment and Drainage Strategy 25 September 2020

Civic Engineers

Contents

1. Introduction ...... 2 Project Background ...... 2 Scope and Objectives ...... 2 Development Proposals ...... 3 2. Existing Site Details ...... 4 Current and Historic Use ...... 4 Existing Watercourses and Waterbodies ...... 5 Existing Drainage ...... 5 Topography ...... 6 Geology ...... 6 3. Relevant Policy and Guidance ...... 8 National Planning Policy Framework ...... 8 Site Specific NPPF Flood Risk Categorisation ...... 10 Site Specific Flood Zone Compatibility ...... 11 Strategic Flood Risk Assessment (SFRA) Level 1 2008 ...... 11 Plan:MK 2016-2031 ...... 11 Wolverton Neighbourhood Plan ...... 13 4. Flood Risk Assessment ...... 14 Fluvial Flooding (Rivers and Streams) ...... 14 Tidal Flooding (Coastal or Estuarine) ...... 16 Reservoir Flooding ...... 16 Canal Flooding ...... 17 Groundwater Flooding ...... 17 Public Sewers, Highway Drainage Flooding and Infrastructure Failure...... 17 Surface Water Flooding to the Site ...... 18 Surface Water Flooding from the Site ...... 19 Historic Flooding ...... 20 Summary of Flood Risk ...... 20 5. Surface Water Management Strategy ...... 21 Existing Site Drainage...... 21

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Existing Site/Pre-development Runoff ...... 21 Post-development Runoff and Attenuation ...... 21 Drainage Hierarchy Points of Discharge ...... 24 Proposed Surface Water Drainage ...... 25 6. Proposed Foul Water Drainage Strategy ...... 27 7. Conclusion ...... 28

Appendix A Development Proposals Appendix B Sewer Records Appendix C Topographical Survey Appendix D Surface Water Calculations Appendix E Drainage Strategy Plan Appendix F Anglian Water Pre-development Enquiry

Flood Risk Assessment and Drainage Strategy

Prepared by Eloise Moir-Mattox

Reviewed by Paul Morris

Civic Job No. 948-01

Issued September 2020

Revised -

This report is the copyright of Civic Engineers and is for the sole use of the person/organisation to whom it is addressed. It may not be used or referred to in whole or in part by anyone else without the express agreement of Civic Engineers. Civic Engineers do not accept liability for any loss or damage arising from any unauthorised use of this report. Civic Engineers is a trading name of Civic 1 Engineers Ltd (registered number 06824088), which is a limited company registered in England, registered address Carver's Warehouse, 77 Dale Street, Manchester M1 2HG

1. Introduction

Project Background This Flood Risk Assessment has been prepared by Civic Engineers to accompany a detailed planning application for the redevelopment of the Agora Centre and adjacent car park. The application is submitted on behalf of Love Wolverton Limited.

The postcode for the site is MK12 5LG and the site is centred around an approximate National Grid Reference of SP817410.

The report provides information on the nature of flood risk at the site and follows Government guidance with regards to development and flood risk, most notably in the National Planning Policy Framework and Planning Practice Guidance.

The report is based on currently available information and preliminary discussions.

Proposals contained or forming part of this report represents the design intent and may be subject to alteration or adjustment in completing the detailed design for this project. Where such adjustments are undertaken as part of the detailed design and are deemed a material deviation from the intent contained within this document, prior approval shall be obtained from the relevant authority in advance of commencing such works.

Where the proposed works to which this report refers are undertaken more than twelve months following the issue of this report, Civic Engineers reserves the right to re-validate the findings and conclusions by undertaking appropriate further investigations at no cost to Civic Engineers.

This report is prepared for the exclusive use of Civic Engineers and our Client. All comments and conclusions in this report are based upon the assumption that the sourced data is reliable. Civic Engineers accepts no liability for any inaccurate conclusions or assumptions resulting from inaccurate information.

Scope and Objectives The assessment is to be undertaken in accordance with the standing advice and requirements of the Environment Agency (EA) for Flood Risk Assessments as outlined in the Communities and Local Governments Planning Policy Guidance to the National Planning Policy Framework (NPPF).

This is a full planning application covering an area of approximately 1.3 ha. Following scrutiny of the UK Governments Long Term Flood Risk information it has been identified that the existing site lies entirely within an area classified as Flood Zone 1, indicating that the probability of flooding from rivers or sea is low (less than 0.1% annual probability of river or sea flooding). As the site is larger than 1 hectare, a Flood Risk Assessment is required to support a planning application to assess mechanisms of potential flood risk, taking into consideration the management of surface water run-0ff.

In April 2015, the Government made changes to the National Planning Policy Framework which made Sustainable Urban Drainage Systems (SuDS) a material consideration in the determination of planning applications for ‘major’ developments. A Detailed Drainage Strategy will therefore be required as part of the Full Planning Application for the development as the site is considered to be

2 Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy a ‘major’ development by the Town and Country Planning Order 2015.This Flood Risk Assessment will:

 Investigate all potential risks of flooding to the site,

 Consider the impact the development may have elsewhere with regards to flooding,

 Consider proposals to mitigate any potential risk of flooding determined to be present; and

 Consider detailed drainage proposals to mitigate flood risk from the site

This report reviews the following information:

 Environment Agency Online Flood mapping

 UK Government Long Term Flood Risk Information

 Milton Keynes Level 1 Strategic Flood Risk Assessment. April 2015

 Anglian Water Asset Location Search Sewer Map, December 2018

 British Geological Survey (BGS) online survey/borehole data; and

 Topographical Survey – SEP Ltd, January 2019

Development Proposals A detailed planning application is to be submitted for redevelopment of the site of the Agora Centre, Wolverton and adjacent car park to provide 86 new homes (Use Class C3) in Blocks A, B, D, E and F as well as 29 homes and a Common House in Block C for a cohousing group (Use Class C3); 9 ground floor commercial and community units comprising 1,012 sqm (Use Classes E and F2(b)); the reinstatement of Radcliffe Street between Church Street and Buckingham Street / The Square; together with associated areas of hard and soft landscaping, car and cycle parking, means of access and plant and equipment.”

Development Proposals are shown on the drawing within Appendix A.

3 Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

2. Existing Site Details

Current and Historic Use The site is located approximately 4.2km north west of the centre of Milton Keynes and is within the local authority area of Milton Keynes Council (MKC).

The earliest available historic mapping (1881) shows the site has been developed since records began with buildings shown from 1881-1969 and a shopping complex and carpark from 1974 onwards.

The site is currently occupied by the Agora Shopping centre within the west side of the site and carparking within the eastern side and is bounded by Church St to the north; ‘St George the Martyr Church’ to the southeast; Buckingham St to the south; and residential land to the west.

The site currently has vehicle and pedestrian access from Church St and Buckingham St.

The site location is shown in Figure 1 below

Figure 1: Site location Aerial Photograph (© Google November 2018)

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Existing Watercourses and Waterbodies No above ground watercourses have been identified within the proposed site.

The following watercourses and waterbodies have been identified within the vicinity of the proposed site:

 Grand Union Canal is approximately 330m north and 380m east of the site; and

 The River Great Ouse is approximately 1.0km north east at its closest point.

Existing Drainage The public sewer records have been obtained from Anglian Water and are enclosed within Appendix B. An extract is included below in Figure 2.

Figure 2: Extract from Anglian Water Asset Location Sewers Map (Dated 20/12/18

The records indicate the following sewer infrastructure within the site:

 A public combined water sewer flows north, adjacent the western site boundary of the proposed site, and into Church St

 A 150mm diameter foul vitrified clay sewer flows south west within the north western corner of the proposed site. The sewer combines with the combined water sewer adjacent the western site boundary.

 A foul and surface water sewer flow north west through the south western corner of the site and combine with the combined water sewer adjacent the western site boundary.

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 A public 375mm vitrified clay combined water sewer flows north from a point approximately halfway along the southern boundary. It combined with a foul sewer (flowing south from the north site boundary) and then flows east and north east, within a 450mm vitrified clay sewer to St George’s way.

 A 225mm vitrified clay surface water sewer flows north west at the approximate centre of the site to the north boundary and into Church St.

The records indicate the following sewer infrastructure within the vicinity of the site:

 A 500mm public combined water sewer flows into a 600mm public combined water sewer, flowing in an easterly direction within Church St, north of the proposed site.

Topography A topographical survey has been undertaken by SEP Ltd dated January 2019 and a copy of the survey drawing is included in Appendix C.

The site generally grades north from the south site boundary, adjacent Buckingham St, with an approximate level of 86.4m AOD, to Church St with an approximate level of 80.6mAOD north west of the site and 81.0m AOD, north east of the site.

The topographical survey indicates that the site is entirely hardstanding within the west side of the site and a combination of hard and soft landscaping and carparking within the east.

Geology The British Geological Survey (BGS) information available online has identified the following geological succession underlying the site:

 Superficial Deposits – Glaciofluvial Deposits, Mid Pleistocene; Sands and Gravel

 Bedrock – Blisworth Limestone Formation - Limestone

The Environment Agency Aquifer Designation Map identifies the site bedrock is classified as a Principal Aquifer which is geology that exhibits high permeability and/or provides a high level of water storage. The superficial drift is identified as a Secondary A Aquifer which is permeable strata capable of supporting water supplies at a local rather than strategic scale and in some cases forming an important source of base flow to rivers.

The Environment Agency Groundwater Vulnerability Map identifies the site as being with a ‘Major Aquifer High’ region, indicating an overall high risk on the likelihood of a pollutant reaching the groundwater.

The BGS provides online records of historic boreholes with 7 boreholes located within the west side of the site. The borehole records detail some of the following strata;

 Dense becoming very dense brown clayey sand with occasional gravel and limestone fragments. Hard yellow buff fine limestone

 Medium dense brown silty clayey sand with gravel and limestone fragments. Pockets of sandy clay also noted. Hard light grey buff fine limestone. Abundant horizontal and vertical open clay filled jointing to 7.0m 6

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 Brown silty clayey sand with gravel and limestone fragments. Weak to medium hard light brown limestone with clay bands. Stiff fissured green brown silty clay

 Hardcore over grey black silty peaty clay with occasional gravel. Firm brown silty sandy clay with occasional gravel

The presence of groundwater was not noted within any of the historic borehole records.

Soilscape data obtained from the Cranfield Soil and AgriFood Institute (CSAI), supported by DEFRA, indicates a ‘freely draining lime-rich loamy soil’ profile with free drainage.

A site-specific Ground Investigation with soakaway testing was conducted by Geotechnical and Environmental Associates Limited (GEA) in June 2019, the ground conditions as per this investigation were as follows.

“The investigation has generally confirmed the expected ground conditions in that, below a variable and locally relatively significant thickness of made ground, Fluvio-Glacial Deposits were found to overlie the Blisworth Limestone, which is turn underlain by mudstone of the Rutland Formation. Below an approximately 0.2m cover of block paving and bedding sand a sub-base of sandy gravel of broken stone extended to depths of approximately 0.3m to 0.4m. This was generally underlain by made ground which generally extended to 0.9m to 2.1m and comprised cobbles and gravel of limestone brick fragments in a matrix of firm pale brown very sandy clay or very clayey sand.

Brick and concrete obstructions thought to represent the former foundations of the terraced houses and the Science and Art Institute were encountered in several of the exploratory positions. This fill material was found to be underlain by firm friable pale brown gravelly very sandy silty clay which graded into dense clayey very gravelly sand which is thought to represent the Fluvio-Glacial Deposits. This stratum was found to be underlain the Blisworth Limestone, which initially comprised limestone fragments in a matrix of off-white clayey sandy silt, which graded into beds of intact limestone at depths of between approximately 2.4m and 6.7m. The rotary boreholes confirmed the Blisworth Limestone to comprise strong to very strong thin to medium bedded sandy limestone and to extend to depths of between approximately 8.3m and 10.8m whereupon the mudstone of the Rutland Formation was encountered. No groundwater was encountered within any of the boreholes.” Regarding hydrology: “The site is almost entirely covered by the existing building and hardstanding and therefore infiltration of rainwater into the ground beneath the site is limited, such that the majority of surface runoff is likely to drain into combined sewers in the road.”

Due to the depths of made ground across the site it is not expected that it will be feasible to dispose of surface water by infiltration. It is proposed that percolation testing is undertaken in advance of the proposed drainage works to determine whether any betterment of the proposed drainage scheme can be achieved through infiltration to the ground.

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3. Relevant Policy and Guidance

National Planning Policy Framework In June 2019 the Ministry of Housing, Communities and Local Government revised the National Planning Policy Framework document (NPPF) and the Planning Practice Guidance which provides guidance on how flood risk should be assessed during the planning and development process.

The NPPF refers to the Flood Zones which are shown on the Environment Agency Flood Map, and establishes the range of uses which are appropriate, or compatible, land uses for each Flood Zone.

The Flood Zones can be summarised as follows:

Zone 1: Low Probability. This zone comprises land assessed as having a less than 1 in 1000 annual probability of river or sea flooding in any one year. (<0.1%)

Zone 2: Medium Probability. This zone comprises land assessed as having between 1 in 100 and 1 in 1000 annual probability of river flooding (1%-0.1%) or between a 1 in 200 and 1 in 1000 annual probability of sea flooding (0.5% - 0.1%) in any year.

Zone 3a: High Probability. This zone comprises land assessed as having 1 in 100 or greater annual probability of river flooding (>1%) or a 1 in 200 or greater annual probability of flooding from the sea (>0.5%) in any year.

Zone 3b: Functional Flood Plain. This zone comprises land where water has to flow or be stored in times of flood. Strategic Flood Risk Assessments should identify this zone.

The ‘Flood Risk and Coastal Change’ category of the Planning Practice Guidance Collection defines the type and nature of different development classifications in the context of their flood risk vulnerability. The following extract outlines the NPPF Flood Risk Vulnerability Classifications.

Essential infrastructure  Essential transport infrastructure (including mass evacuation routes) which has to cross the area at risk  Essential utility infrastructure which has to be located in a flood risk area for operational reasons, including electricity generating power stations and grid and primary substations; and water treatment works that need to remain operational in times of flood.  Wind turbines.

Highly vulnerable  Police and ambulance stations; fire stations and command centres; telecommunications installations required to be operational during flooding.  Emergency dispersal points.  Basement dwellings.  Caravans, mobile homes and park homes intended for permanent residential use.  Installations requiring hazardous substances consent. (Where there is a demonstrable need to locate such installations for bulk storage of materials with port or other similar facilities, or such installations with energy infrastructure or carbon capture and storage installations, that require coastal or water-side locations, or need to be located in other 8

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high flood risk areas, in these instances the facilities should be classified as ‘Essential Infrastructure’). More Vulnerable  Hospitals  Residential institutions such as residential care homes, children’s homes, social services homes, prisons and hostels.  Buildings used for dwelling houses, student halls of residence, drinking establishments, nightclubs and hotels.  Non–residential uses for health services, nurseries and educational establishments.  Landfill* and sites used for waste management facilities for hazardous waste.  Sites used for holiday or short-let caravans and camping, subject to a specific warning and evacuation plan. Less Vulnerable  Police, ambulance and fire stations which are not required to be operational during flooding.  Buildings used for shops; financial, professional and other services; restaurants, cafes and hot food takeaways; offices; general industry, storage and distribution; non-residential institutions not included in the ‘more vulnerable’ class; and assembly and leisure.  Land and buildings used for agriculture and forestry.  Waste treatment (except landfill* and hazardous waste facilities).  Minerals working and processing (except for sand and gravel working).  Water treatment works which do not need to remain operational during times of flood.  Sewage treatment works, if adequate measures to control pollution and manage sewage during flooding events are in place. Water-compatible development  Flood control infrastructure.  Water transmission infrastructure and pumping stations.  Sewage transmission infrastructure and pumping stations.  Sand and gravel working.  Docks, marinas and wharves.  Navigation facilities.  Ministry of Defence defence installations.  Ship building, repairing and dismantling, dockside fish processing and refrigeration and compatible activities requiring a waterside location.  Water-based recreation (excluding sleeping accommodation).  Lifeguard and coastguard stations.  Amenity open space, nature conservation and biodiversity, outdoor sports and recreation and essential facilities such as changing rooms.  Essential ancillary sleeping or residential accommodation for staff required by uses in this category, subject to a specific warning and evacuation plan.

” * “ Landfill is as defined in Schedule 10 of the Environmental Permitting (England and Wales) Regulations 2010.

Paragraph: 066 Reference ID: 7-066-20140306 Revision date: 06 03 2014 Figure 3: Table 2 from ‘Flood risk and coastal change’ Guidance (2014)

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The flood risk vulnerability and flood zone ‘compatibility’ has been summarised in Table 1 below.

Flood Risk Vulnerability Essential Highly More Less Water Classification (see Table 2) Infrastructure Vulnerable Vulnerable Vulnerable Compatible Zone 1 √ √ √ √ √ Exception Zone 2 √ √ √ √ Test Required Exception Test Exception Zone 3a × √ √ Table 1) Table 1) Required Test Required Zone 3b (functional Exception Test Flood Zone (See Zone Flood × × × √ floodplain) Required √ Development is appropriate × Development should not be permitted. Table 1: Flood Risk Vulnerability and flood zone compatibility from ‘Flood risk and coastal change’ Guidance (2014).

Site Specific NPPF Flood Risk Categorisation To assess the NPPF flood risk classification for the site, the Government (Environment Agency) web based ‘Flood Map for Planning’ is reviewed, which is used to inform planning of a site’s Flood Zone(s) and the probability of flooding from rivers or sea (not taking into account the presence of flood defences). The Government web based ‘Long Term Flood Risk Assessment for Locations in England’ should also be used to identify the flood risks from rivers and seas, surface water and reservoirs.

From the ‘Flood Map for Planning’, shown below in Figure 4, it can be seen that the proposed site and the surrounding area are entirely located within an area classified as Flood Zone 1 (low risk of flooding from rivers or sea).

Figure 4: Flood Map for Planning (©Crown Copyright)

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Site Specific Flood Zone Compatibility The proposals for the development site are likely to fall within the following categories:

 ‘Buildings used for dwelling houses’,

 ‘Buildings used for shops’.

This type of development is classed as ‘more vulnerable’ in the Flood Risk Vulnerability Classification (Table 2). Whilst there are also less vulnerable uses (shops) proposed, it is the more vulnerable uses that have the greater priority in any assessment.

This site is located within Flood Zone 1, for which all development is deemed to be appropriate and neither the sequential nor the exception test is required (refer to Table 1 for Flood Zone Compatibility, taken from the NPPF ‘Flood risk and coastal change’ Guidance).

Strategic Flood Risk Assessment (SFRA) Level 1 2008 The Milton Keynes Council SFRA advises the following for ‘Proposed Development in Low Probability Flood Zone 1’;

“FRAs within Flood Zone 1 should primarily take consideration of how the ability of water to soak into the ground may change with development, along with how the proposed layout of development may affect drainage systems. This is to ensure surface water generated by the site is managed in a sustainable manner and does not increase the burden on existing infrastructure and/or flood risk to neighbouring property. “

The SFRA advises the following regarding the application of SUDS;

“The PPG, which accompanies the NPPF, indicated that priority should be given to the use of SUDS in new developments. Appropriate deployment of SUDS within a development can offer benefits in terms of reductions in flood risk, improvements to water quality, quicker replenishment of groundwater and improved visual amenity”

Plan:MK 2016-2031 Policy FR1 states that:

“MANAGING FLOOD RISK

A. All new development must incorporate a surface water drainage system with acceptable flood control and demonstrate that water supply, foul sewerage and sewerage treatment capacity is available or can be made available in time to serve the development. Suitable access is safeguarded for the maintenance of water supply and drainage infrastructure.

B. Plan:MK will seek to steer all new development towards areas with the lowest probability of flooding. The sequential approach to development, as set out in national guidance, will therefore be applied across the Borough, taking into account all sources of flooding as contained within the Council’s Strategic Flood Risk Assessment (SFRA)…

C. [Relates to development within areas of flood risk as such does not apply to this development]

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

D. [ Relates to development within areas of flood risk as such does not apply to this development]

E.. A site specific FRA will be required for:

1. All sites of 1Ha or more in Flood Zone 1;

2. All site within Flood Zones 1 and 2;

3. All sites highlighted as being at high risk from surface water flooding, or which are located within a Critical Drainage Catchment (CDC), s identified in the Milton Keynes Surface Water Management Plan. In this case the FRA will be required to demonstrate that the development will not increase the flood risk to the CDC and where possible will provide an improvement to the existing situation

F. The FRA should include an assessment of flood risk to and from the proposed development, and demonstrate hoe the development will be safe, will not increase flood risk elsewhere and where possible will reduce flood risk overall in accordance with the NPPF and PPG.”

Policy FR2 states that:

“SUSTAINABLE DRAINAGE SYSTEMS (SUDS) AND INTEGRATED FLOOD RISK MANAGEMENT

A. Plan:MK advocates the continuation of a strategic, integrated approach to managing flood risk which seeks the management of surface water to be planned at the largest appropriate scale for the new development and incorporated into the site at the earliest opportunity in the design process.

B. New development is required to incorporate SuDS; in line with national policy and guidance and, which meet the requirements set out in national standards and the Council’s relevant local guidance. It is expected that:

1. Flood risk management and SuDS will be provided at a strategic scale and in an integrated manner, wherever possible;

2. Space will be specifically set aside for SuDS and fluvial flood risk reduction features and used to inform the overall layout of development sites;

3. Above ground attenuation will be provided in preference to below ground attenuation;

4. SuDS will be designed as multi-purpose green infrastructure and open space, to maximise additional environmental, biodiversity, social and amenity value, wherever possible. The use of land to provide flood storage capacity should not conflict with required amenity and recreation provision - floodplains and floodplain habitats should be safeguarded;

5. SuDS will be designed with an allowance for climate change and the potential impact it may have over the lifetime of the proposed development;

6. Proposals for development within Critical Drainage Catchments, as identified in the Milton Keynes Surface Water Management Plan, should investigate the potential for the scheme to reduce or mitigate existing risk in the surrounding area;

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7. All surface water drainage proposals for new development must include full details of the means of achieving future management, maintenance and adoption of the systems, prior to approval of any planning permission, to ensure that it will function effectively over the lifespan of the development. This will include details of funding and should be formulated through discussion with the relevant responsible bodies, including Milton Keynes Council, The Parks Trust, Anglian Water and the Internal Drainage Board;

8. Development will ensure no adverse impact on the functions and setting of a watercourse and its associated corridor;

9. Development should avoid building over or culverting watercourses, encourage the removal of existing culverts and seek opportunities to create wetlands and wet grasslands and woodlands and restore natural river flows and floodplains.”

Wolverton Neighbourhood Plan Policy W2 states that:

“ With the exception of minor alterations and householder applications, all development and redevelopment within Wolverton Town Centre will as appropriate to scale and location and viability testing… include the introduction of water efficiency measures and sustainable urban drainage systems which reduce flood risk and add ecological value and interest to new development.”

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

4. Flood Risk Assessment The potential sources of flooding to the development have been assessed and are discussed below.

Fluvial Flooding (Rivers and Streams) From the Government (Environment Agency) flooding from rivers and seas maps for planning:

 Where a site is located in a dark blue shaded zone, this indicates that the site is within Flood Zone 3b where there is a chance of flooding of greater than 1 in 30 (3.3%).

 Where a site is located in a blue shaded zone, this indicates that the site is within Flood Zone 3a where there is a chance of flooding of between 1 in 100 (1%) and 1 in 30 (3.3%).

 Where a site is located in a turquoise shaded zone; this indicates that the site is within Flood Zone 2 where there is a chance of flooding between 1 in 1000 (0.1%) and 1 in 100 (1%).

 Where a site is located in a white (unshaded) area, it is generally deemed to be classified as Flood Zone 1 where there is a chance of flooding of less than 1 in 1000 (0.1%).

Flooding to the site from rivers and seas is indicated in Figure 5 and it can be seen that the entire site is within an area classified as Flood Zone 1, therefore the site is considered to be at very low risk from fluvial flooding.

Figure 5: Long Term Flood Risk Assessment Map – Flood Risk from Rivers and Seas (© Crown Copyright)

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The Impacts of Climate Change on Fluvial Flood Risk

Peak river flow allowances for various river basins, available from Environment Agency, are suitable for both Flood Risk Assessments and Strategic Flood Risk Assessments. They consider potential increase in peak river flow due to climate change. Table 3 below, based on data provided by the Environment Agency, shows anticipated flow changes for the Anglian district.

Figure 6: Map of the Anglian River Basin District (Environment Agency 2015)

Total potential change anticipated for the: River Basin Allowance District Category ‘2020s’ ‘2050s’ ‘2080s’ (2015-2039) (2040-2069) (2070-2115) Upper End 25% 35% 65% Anglian Higher Central 15% 20% 35% Central 10% 15% 25% Table 3: Peak river flow allowances for the Anglian river basin district (use 1961 to 1990 baseline)

Based on the nature of the development, a lifespan in excess of 60 years is anticipated. Therefore, the potential climate change allowance for 2070-2115 ranges between 25% for the central allowance and 65% for the upper end allowance.

The Environment Agency presents a set of recommendations based on the level of vulnerability of a proposed structure and its Flood Zone. The higher the vulnerability, and the riskier the Flood

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Zone, the higher the assumed flow increase. However, no recommendations were made for Flood Zone 1, due to its low flood risk.

Tidal Flooding (Coastal or Estuarine) Based on the site elevation and location (approximately 113km from the nearest coastal body of water) the risk from tidal flooding is considered very low.

Reservoir Flooding Reservoir flooding is extremely unlikely to happen and there has been no recorded loss of life in the UK from reservoir flooding since 1925. The Environment Agency is the enforcement authority and ensures that reservoirs are inspected regularly, and essential safety work is carried out.

The Flood Risk from Reservoirs map, shown below in Figure 7, shows the largest areas that might be flooded if a reservoir were to fail and release the water it holds. Since this is a prediction of a worst-case scenario, it is very low risk that a reservoir flood would be this large.

The site, and surrounding area are not classified as being affected by reservoir flooding and is therefore considered at very low risk.

Figure 7: Long Term Flood Risk Assessment Map – Flood Risk from Reservoirs (© Crown Copyright)

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Canal Flooding The nearest canal to the proposed development is the Grand Union Canal which is approximately 380m east of the proposed site.

As canals are a controlled water body, and do not pose a direct flood risk, the residual risk of canal flooding is usually associated with lower probability events such as overtopping and/or the breaching of embankments.

Given the information above, it is considered that there is a very low risk of canal flooding to the site.

Groundwater Flooding The Milton Keynes Council SFRA advises that there is the potential for groundwater flooding to occur within the Milton Keynes Borough, based on the three key groundwater flooding mechanisms that have been identified;

 Surface Water to Groundwater interaction within superficial aquifers along the River Ouzel, the River Great Ouse and their tributaries. Groundwater flooding may be associated with the Alluvium, River Terrace Deposits and the Head deposits where they are in hydraulic continuity with these surface watercourses…

 Direct groundwater recharge to superficial and bedrock aquifers. During periods of high rainfall, perched water tables can exist within these deposits, developed through a combination of natural rainfall recharge and artificial recharge (e.g. Leaking water mains)

 Made ground in various locations. Groundwater flooding may occur where the ground has been artificially modified to a significant degree.

The MKC SFRA also states “In the north, where the underlying geology is predominantly limestone or the Kellaways Formation and Oxford Clay Formation there is a limited potential for groundwater flooding to occur”.

The SFRA ‘Susceptibility to Groundwater Flooding’ map shows the proposed site within an area of ‘Limited potential for groundwater flooding to occur’. It should be noted however that this information should not be viewed as fully comprehensive due to the nature of groundwater flooding and there are potentially additional areas of risk within the area.

Given the above information. the risk of groundwater flooding to the site is considered low.

Public Sewers, Highway Drainage Flooding and Infrastructure Failure There are various public sewers within the vicinity of and within the site.

A Pre-Development enquiry has been issued to Anglian Water and their response is enclosed within Appendix F. Their response did not comment on historic flooding from sewer infrastructure.

The MKC Level 1 SFRA ‘Record Incidents of Sewer Flooding’ map shows the site is not within an area of recorded flooding for the last 10 years.

Providing Anglian Water and Milton Keynes Council maintain their drainage assets in the vicinity of the site, the risk of flooding to the proposed development site from public sewer or highway drainage is considered to be low.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Surface Water Flooding to the Site Surface water flooding can be caused when rainwater, during extreme rainfall events, does not drain away through the normal drainage system or soak into the ground. Surcharging sewers can result in overland flows which if originating at a higher elevation than a development site can potentially pose a flood risk.

Surface water flooding is dependant primarily on topography which dictates either the flow path of overland flow which is not contained within public sewers, or areas in which ponding may occur. Surface water flooding is more difficult to predict than the risk of flooding from Rivers or Sea as it is dependent on the amount of rain which will fall in a very localised area, the specific topography of that area and the capacity and functionality of the drainage network within that area

From the Government (Environment Agency) Flood Risk from Surface Water (extent of flooding) map;

 Where a site is located in a dark blue shaded zone, this indicates that the site is at high risk of flooding where there is a chance of flooding of greater than 1 in 30 (3.3%).

 Where a site is located in a mid-blue shaded zone, this indicates that the site is at medium risk of flooding where there is a chance of flooding of between 1 in 100 (1%) and 1 in 30 (3.3%).

 Where a site is located in a light blue shaded zone; this indicates that the site is at low risk of flooding where there is a chance of flooding between 1 in 1000 (0.1%) and 1 in 100 (1%).

 Where a site is located in a white (unshaded) area; this indicates that the site is at very low risk of flooding where there is a chance of flooding of less than 1 in 1000 (0.1%).

The extent of flooding to the site from surface water is indicated in Figure 8 and it can be seen that the majority of the site is located in an area classified as being at ‘Very Low’ risk of flooding from surface water.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Figure 8: Long Term Flood Risk Assessment Map – Flood Risk from Surface Water (© Crown Copyright)

Several localised areas adjacent the existing Agora Shopping centre and Church St display a low risk of flooding.

The topography across the site will be adjusted to suit the proposed development and surface water managed through the on-site surface water drainage network.

Given the above information the risk of surface water flooding to the site is considered low.

Surface Water Flooding from the Site Developers are responsible for ensuring that new development does not increase the flood risk elsewhere. The proposed surface water drainage network shall be designed to not flood for the critical 1 in 30-year storm event and flood water generated up to the critical 1 in 100-year plus climate change storm event shall be contained within areas on site so as not to cause damage to buildings, essential services or adjoining developments and services.

A development has the potential to increase flood risk where additional run-off from proposed roads and paved areas is discharged freely into the downstream drainage network. The development will include increased permeable areas, landscaping areas and incorporate sustainable drainage features to provide betterment over the existing condition.

. A detailed assessment of the proposed surface flows is carried out within the drainage strategy section of this report.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Historic Flooding Historic flood events are noted within the SFRA, which details the nearest recorded event as occurring 2km north east in New Bradwell in 1998 and 1947 from the River Great Ouse and in 1968 from Loughton Brook. The Environment Agency flood event outlines only show flooding to gardens and ground, not buildings, for these events.

The existence of historic flooding does not necessarily indicate that flooding will be a future risk.

Summary of Flood Risk From the evidence collated and subsequent negotiations, the flood risk proposed to the development can be summarised as follows:

 Fluvial (Rivers and Streams) – Very low Risk

 Tidal – Very low Risk (Not applicable)

 Reservoir – Very low Risk

 Canals – Very low Risk

 Groundwater – Low Risk

 Public Sewers – Low Risk

 Surface Water – Low Risk

 Historic – No events noted as specifically affecting the proposed development site.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

5. Surface Water Management Strategy

Existing Site Drainage The Anglian Water public sewer records have been obtained and they indicate the following sewers present within the site:

 A public combined water sewer flows north, adjacent the western site boundary of the proposed site, and into Church St

 A foul and surface water sewer flow north west through the south western corner of the site and combine with the combined water sewer adjacent the western site boundary.

 A 225mm vitrified clay surface water sewer flows north west at the approximate centre of the site to the north boundary and into Church St.

The sewer records are enclosed within Appendix B.

As per the proposed layout (Appendix A) the residential development will occupy all areas of the site and as such the existing public combined water sewers will require formal diversion. Initial discussions have been held with Anglian Water regarding the principle of diversion.

Existing Site/Pre-development Runoff The site is currently developed and considered 100% impermeable for the purpose of drainage runoff and drains to the public sewer.

Pre-development run off rates have been calculated using a two-pipe simulated network within Micro Drainage and the Surface Water Calculations are included in Appendix D.

Based on the 1.3ha area dedicated to development/to be positively drained, the existing runoff rate is 169.1 l/s

Post-development Runoff and Attenuation The drainage design as appended to this report will restrict the post-development flows to 118.4 l/s, allowing 30% betterment on pre-development runoff. It is not practicable to discharge surface water from this brownfield site at greenfield run off rates and as such the network as designed provides a betterment on the guidance from Anglian Water which states that the discharge rate “will be limited to the existing 1in1 year rate or an appropriate rate as agreed with Anglian Water.”

In February 2016, the Environment Agency released updated climate change allowances for peak rainfall intensities which should be applied to new developments. Table 4 demonstrates the climate change allowances with central and upper end allowances being considered. 21

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Based on the nature of the development, a lifespan in excess of 60 years is anticipated. The potential climate change allowance for 2070-2115 ranges between 20% for the central allowance and 40% for the upper end allowance. As such, the design will consider an allowance of 30% climate change on peak rainfall intensity for all calculations.

Total potential Total potential Total potential Applies change anticipated change anticipated change anticipated across all of for the ‘2020s’ (2015 for the ‘2050s’ (2040 for the ‘2080s’ (2070 England to 2039) to 2069) to 2115) Upper end 10% 20% 40% Central 5% 10% 20% Table 4: (Extract Environment Agency Guidance) Peak Rainfall Intensity Allowance in small and urban catchments

In restricting the flows from the development site there will be a requirement to provide attenuation to accommodate flows up to the 1 in 100-year event with a climate change allowance of 30%. The purpose of the attenuation being to maintain operation on the system during the 1 in 1yr, 1 in 30yr and the 1 in 100yr (plus climate change) storm events.

The required volume of attenuation has been calculated using Micro Drainage, assuming the proposed development has 1.197ha of impermeable area (based on the Landscape Masterplan Plan - Appendix A) and Surface Water Calculations are included in Appendix D. The results are as follows:

 1 in 100-year event (incl. 30% climate change) – Attenuation volume; 284m3

Any phasing proposed for the development may require temporary or staged flow restriction and attenuation.

Potential Sustainable Drainage Systems (SuDS) Features to be Considered

Section 1.1 of the SuDS Manual (Ciria C753) states the following:

“Sustainable drainage systems (SuDS) can deliver multiple benefits.

Surface water is a valuable resource and this should be reflected in the way it is managed and used in the built environment. It can add to and enhance biodiversity, beauty, tranquillity and the natural aesthetic of buildings, places and landscapes and it can help make them more resilient to the changing climate.

The philosophy of sustainable drainage systems is about maximising the benefits and minimising the negative impacts of surface water run-off from developed areas.

The SuDS approach involves slowing down and reducing the quantity of surface water runoff from a developed area to manage downstream flood risk,and reducing the risk of that runoff causing pollution. This is achieved by harvesting, infiltrating, slowing, storing, conveying and treating runoff on site and, where possible, on the surface rather than underground. Water then becomes a much more visible and tangible part of the built environment, which can be enjoyed by everyone.”

The SuDS Manual describes the four pillars of SuDS design as Water Quality, Water Quantity, Amenity and Biodiversity as illustrated in Figure 10 below.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Figure 9: Sustainable Development Objectives (Representation of Figure 2.1 of The SuDS Manual)

Various SuDS methods have been summarised in the table below to assess and establish which are most feasible for the proposed post development site.

SuDS Method Feasibility, Given Site and Project The typical pitched roof used in residential housing is not a desirable foundation for green and blue roofs. Green and Blue Green & Blue Roofs roofs do however provide other environmental and cost benefits (reductions in insulation and heating costs) and should still be considered where practicable Basins and ponds increase biodiversity and amenity of the area; Basins and Ponds – provide attenuation; and improve water quality. This method does Above Ground however occupy large areas of developable land and requires storage suitable offsets from buildings. Due to the urban location of the site, basins and ponds are not a feasible option. Raingardens and tree pits are currently proposed within the Rain Gardens & Tree highways areas which can potentially provide additional surface Pits water storage for highway runoff. Filter strips and swales can be used adjacent highways to reduce Filter Strips and and treat runoff. Due to the urban nature of the site swales and Swales filter strips are not proposed in this instance. Rainwater harvesting is not a viable option due to the rainfall yield Store water for later on the roof area being significantly less than the water demand for use the residential units. However, water butts may be placed in the rear courtyard gardens for communal use. Based on the geology information from BGS, it appears likely that infiltration would be feasible for the site, however the EA Groundwater Vulnerability Map indicates the site to be within a region at high risk of groundwater contamination. The historic bore Infiltration Devices hole records also indicated strata of clay and peat. For these reasons it is recommended that infiltration not be incorporated into the drainage strategy. Site specific ground investigations should be conducted prior to detail design. 23

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Permeable surfaces allow rainwater to infiltrate through the surface into an underlying storage layer. Permeable surfaces have Permeable surfaces been considered but ruled out due to the topography of the site which generally falls from south to north meaning that water could not be efficiently stored within the sub-base. A vortex flow control device is to be used to restrict the surface Vortex Control and water flow from the site to proposed runoff rates. Tanked Attenuation Tanked attenuation systems provide high storage capacity and systems can be incorporated within road pavements and under landscaping. Table 5: SuDS Suitability Assessment

Based on the current proposed layout plan, the SuDS methods that will be incorporated into the drainage design will be rain gardens, vortex flow control, attenuation tanks and water butts.

The surface water run-off from the site will be from roofs and residential streets and as such the risk of contamination and suspended silts/debris being present within surface water will be low.

Maintenance of SuDS will be the responsibility of the developer/operator of the development,

Drainage Hierarchy Points of Discharge The NPPF Planning Practice Guidance Paragraph 080 states that:

“Generally, the aim should be to discharge surface run off as high up the following hierarchy of drainage options as reasonably practicable:

1. into the ground (infiltration);

2. to a surface water body;

3. to a surface water sewer, highway drain, or another drainage system;

4. to a combined sewer.”

Infiltration Potential Sustainable Drainage Systems (SuDS) Features to be Considered

BGS Drift Maps indicates the site geology is that of Blisworth Limestone Formation (Bedrock) and Glaciofluvial Deposits, Mid Pleistocene (Superficial). The bedrock is noted as a Principal A Aquifer and the superficial drift as a Secondary A Aquifer. Based on the geology information from BGS, it appears likely that infiltration would be feasible for the site, however the EA Groundwater Vulnerability Map indicates the site to be within a region at high risk of groundwater contamination.

The historic bore hole records also indicated strata of clay and peat which suggest limited infiltration.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Water Body

The nearest water body to the development is the Grand Union Canal, approximately 330m north of the site. Discharging to the canal would require construction within public and private land and is unfeasible for the development.

Surface Water Sewer

There are no public surface water sewers within the site, suitable to take the development’s runoff.

Combined Sewer

The Anglian Water Asset records indicate the following public sewer mains within the site;

 A public combined water sewer flows north, adjacent the western site boundary of the proposed site, and into Church St

 A 375mm vitrified clay combined water sewer flows north from a point approximately halfway along the southern boundary. It combined with a foul sewer (flowing south from the north site boundary) and then flows east and north east, within a 450mm vitrified clay sewer to St George’s Way.

The recommended point of connection for Block A of the proposed development is the existing combined water sewer adjacent the western site boundary. The recommended point of connection for Blocks B-F, is the existing 450mm combined water sewer at a point close to St George’s Way.

The surface water discharge options are summarised below in Table 6.

Surface Water Potential Description Disposal Method Historic borehole records indicate the site is underlain with clay; and Infiltration ✘ EA mapping shows the site is within a region at high risk of groundwater contamination. Water Body ✘ The are no waterbodies in close proximity to the proposed site. Surface Water There are no public surface water sewers within the proposed site. Sewer ✘ Combined Water Existing public combined water sewers are present within the site and Sewer ✔ are the proposed point of connection. Table 6: Summary of Surface Water Disposal

Proposed Surface Water Drainage Any new development site drainage should be designed in accordance with current best practice to provide adequate capacity not to flood for the critical 1 in 30-year storm event and flood water generated for up to the critical 1 in 100-year plus climate change storm event shall be constrained within the areas on site so as not to cause damage to buildings, essential services, adjoining developments and services.

As the site is developed brownfield, surface water drainage will be restricted such that it does not exceed the pre-development run off rate with the aim of achieving a 30% reduction; this provides a betterment on the guidance from Anglian Water which states that the discharge rate “will be limited to the existing 1in1 year rate or an appropriate rate as agreed with Anglian Water.”

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Based on the current proposed layout, a traditional system of pipes and manhole will convey flows across the site to underground attenuation tanks, before discharging at a restricted rate to the existing public combined water sewer network.

The proposed drainage strategy is enclosed in Appendix E.

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

6. Proposed Foul Water Drainage Strategy A pre-development enquiry has been issued to Anglian Water and a response is awaited. This is standard procedure and is likely to be sufficient for disposal of the foul water.

The current proposal includes collecting the foul drainage from each residence via a piped system and discharging to the existing public combined sewers at the western and eastern sides of the site, at an unrestricted rate.

Any connection to the public sewer is subject to formal agreement with Anglian Water under Section 106 of the Water Industry Act 1991.

The proposed drainage strategy plan is enclosed in Appendix E

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

7. Conclusion The proposed site of the Wolverton Agora development is currently developed and classified as brownfield. Historic mapping shows the site has been developed as residential and other buildings, since records begin in 1881. Historic mapping from 1974 shows the site in its current use as the Agora Shopping Centre.

The existing site lies entirely within an area classified as Flood Zone 1, indicating that the probability of flooding from rivers or sea is low (less than 0.1% annual probability of river or sea flooding).

The scheme proposed the residential-led mixed use development with associated parking and landscaping areas. Residential developments are classified as ‘more vulnerable’ by the NPPF, however as it is within Flood Zone 1 the development is deemed appropriate and neither the sequential nor the exception test is required.

Flood Risk from all sources have been assessed in accordance with the requirements of National and Local Planning Policy and conclusions are summarised below:

 Fluvial (Rivers and Streams) – Very low Risk

 Tidal – Very low Risk (Not applicable)

 Reservoir – Very low Risk

 Canals – Very low Risk

 Groundwater – Low Risk

 Public Sewers – Low Risk

 Surface Water – Low Risk

 Historic – No events noted as specifically affecting the proposed development site.

Anglian Water Asset records show existing public combined water sewers are present within the proposed site.

Pre-development/existing runoff rates have been calculated at 169.1l/s, based on a 100% impermeable site area of 1.3hectares. Based on the nature of the development, a lifespan in excess of 60 years the design will consider an allowance of 30% climate change for all calculations.

Surface Water Discharge for the development will be restricted to 118.4 L/s providing a betterment on the existing scenario and aligning with all relevant National and Local Planning Policy. Based on the current layout plan the most feasible SuDS methods that will be incorporated into the drainage design will be rain gardens and proprietary below ground attenuation tanks, consistent with NPPF paragraph 80.

The foul water drainage from each development will be collected via a piped system and discharge to the existing public foul sewer at the west and eastern points of the site, at an unrestricted rate. This is subject to formal agreement with Anglian Water under S106 of the Water Industry Act 1991

Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Appendix A Development Proposals

Key

Application Boundary

Love Wolverton Ownership Boundary

Indicative highways and public realm improvements to be delivered by MKC

ROAD A Proposed building footprints STRATFORD Asphalt

GLYN Coloured asphalt

Concrete paving SQUARE Clay pavers

Self binding gravel paths

Amenity grass

CREED Private amenity grass

Hedgerows

STREET Public realm planting

Communal planting

Play Grade Sand (BSEN1177:2018)

+ Proposed trees

Existing trees: Category A (High) Category B (Moderate) Category C (Low) Category U (Unsuitable)

Root Protection Area (RPA)

Proposed attenuation tank

RADCLIFFE

STREET

T05

T03 4

2 T03 T05

T01

T01 2 T02 T02 T01 3 T01 F

RPA RPA RPA RPA

RPA RPA

x 2 RPA RPA

RPA BIKE RPA

RPA RPA

RPA T03 RPA RPA RPA

RPA

RPA 7 RPA

RPA RPA

RPA

7 RPA RPA

RPA

T01 / Charging RPA

RPA

Layover RPA / D RPA

RPA Alighting RPA 5

RPA

RPA T08RPA STONE 5 RPA T04 RPA WALL RPA

RPA

2 RPA x

RPA

BIKE RPA

RPA RPA RPA T08 RPA RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

ASHP RPA

RPA

RPA ASHP RPA RPA

RPA

RPA RPA

RPA STONE RPA T03 RPA

RPA T01 RPA RPA x 4 RPA RPA RPA RPA RPA BIKE RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

ASHP RPA RPA WALL RPA RPA RPA RPA RPA

ASHP RPA RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA

RPA T06 RPA ASHP RPA

RPA RPA

RPA

RPA RPA

T03 RPA STOP ASHP RPA 2 BUS RPA RPA

RPA RPA

RPA

RPA T08 RPA

RPA

RPA C RPA

RPA

RPA T03 T06 6* RPA

RPA

RPA ASHP RPA

RPA

RPA 5 RPA ASHP T09

RPA

RPA T01 RPA

RPA

T04 RPA

RPA

2 ASHP RPA

x RPA

BIKE RPA RPA

RPA

RPA RPA 7* RPA

RPA RPA T07 RPA RPA RPA T01 T07 WALL RPA RPA future RPA RPA RPA RPA

RPA

RPA RPA

RPA STONE RPA RPA RPA

RPA Potentialaccess RPA

RPA

T06 RPA x 4 T06 RPA BIKE RPA Bay Storage RPA

RPA T09 RPA RPA Loading RPA RPA

RPA

RPA RPA

18 RPA B RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA

RPA T10 RPA WALL RPA

RPA

RPA STONE

RPA

RPA ASHP RPA

RPA

RPA RPA RPA RPA RPA RPA

RPA RPA RPA 1:15 T07 ASHP 3 RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

T06 RPA

RPA RPA RPA ST

RPA RPA

RPA

RPA 1:38 RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

1:21 RPA

RPA RPA GEORGES 1:14

RPA

RPA 12*

RPA

T06 RPA ASHP RPA

RPA WALL RPA A RPA ASHP RPA RPA

1:13 RPA

RPA 1:18 ASHP STONE RPA

RPA RPA

RPA RPA 1:35 T06 RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

5 RPA

ASHP RPA ASHP RPA

1:14 RPA 5 T06 RPA 13

RPA

T10 T06 RPA

RPA WALL RPA

T06 RPA

STONE RPA

RPA

RPA WAY

RPA

T09 RPA 1:20 RPA RPA T08 RPA RPA

1:30 RPA

RPA

RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA T06 RPA RPA RPA T08 RPA RPA T06 RPA RPA

RPA 1:13 ASHP RPA RPA ASHP WALLRPA RPA RPA RPA RPA RPA

RPA RPA RPA 1:13 RPA RPA T08 RPA STONE

RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA T11 RPA RPA RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA 1:30 RPA

RPA

RPA RPA RPA RPA

RPA ASHP RPA

RPA RPA RPA RPA ASHP 1:14 RPA

RPA

RPA RPA

RPA 3 RPA RPA

1:14 RPA

RPA RPA

RPA

RPA 5 RPA

x10 RPA Rev: Notes: Date: Dr by Ap by RPA

RPA

NEXTBIKE RPA

RPA

RPA . DOCK RPA

B RPA

RPA

1:12 RPA

RPA RPA

RPA

RPA RPA

RPA

T06 RPA

RPA

43* RPA 1:14

RPA

RPA RPA

RPA

RPA RPA RPA RPA

TG3 RPA

RPA RPA

RPA

RPA RPA BRICK WALL

RPA

RPA RPA

RPA

RPA RPA WALL RPA 6 BRICK RPA

RPA

RPA RPA RPA 44*

RPA RPA

RPA WALL RPA RPA BRICK RPA RPA T01 RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA T03 RPA

RPA RPA

RPA RPA BIKE x6 RPA RPA

RPA

RPA RPA

RPA RPA RPA 5 RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA

RPA

RPA RPA DRIVE RPA

RPA

RPA RPA

RPA RPA RPA 2 RPA RPA .5% T03

BRICK

T01 WALL

2 .5% LODGE

E CEDAR

BRICK

WALL

ASHP

DR ASHP

ASHP IA

H/C ASHP

H/C

ASHP

RLV 5 BLV T11 5 RPA RPA RPA

RPA RPA RPA RPA RPA RPARPA

RPA T05 RPA

RPA RPA

RPA

RPARPA

RPA RPA RPA

RPA

RPA RPA T11 RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA EV RPA RPARPA

RPA

RPA RPA

RPA T11 RPA

RPA

RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

T11 RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPARPA

RPA

RPA RPA

Stair: WC RPA

RPA Stair:

EV RPA .70 S.M. 2 RPA RPA

Flr-to-Flr

RPA

Flr-to-Flr RPA

RPA RPA

WC RPA . RPA 2.70 S.M

RPA Stair: RPA

WC Height RPA RPA

Height

. RPA 2.70 S.M RPA

Flr-to-Flr

RPA

RPA RPA does

RPA

does

WC RPA

RPA . RPA 2.70 S.M not

RPA RPA RPA Height not

RPA

allow

47 RPA RPA

allow

RPA

RPA does

RPA any 48 RPA RPA any

RPA

not risers

risers RPA

RPA RPA RPA allow 49

. RPA RPA

. RPA RPA RPA

RPA any

RPA RPA

RPA RPA risers RPA

RPA

RPA RPA

RPA RPA . RPA

RPA RPA RPA RPA RPA RPA

RPA 6 RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPARPA RPA RPA RPA RPARPA

RPARPA RPA RPA RPA RPARPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA Original By: Date: Ap by RPA

RPA JH 14-08-2020 SG

5 CC

STREET BUCKINGHAM

10 Little Lever Street t. +44 (0)161 200 5500 e. [email protected] Manchester M1 1HR f. +44 (0)161 237 3994 w. www.urbed.coop

Drawing Title: Landscape Plan 00

Project Title: Wolverton Agora

Client: TOWN

Project Number: Issue Status: 1068 Planning

Drawing Number: 1068-URBED-Z0-00-DR-L-Landscape_Plan_00

Scale: Date: Revision: 1:500@A1/1:1000@A3 10-09-2020 P4

This drawing is to be read in conjuction with all related drawings. Do not scale from this drawing. this drawing is copyright and remains property of URBED (urbanism, environment and design) Ltd. Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Appendix B Sewer Records

(c) Crown copyright and database rights 2018 Ordnance Survey 100022432 Date: 20/12/18 Scale: 1:1250 Map Centre: 481677,241063 Data updated: 04/09/18 Our Ref: 292416 - 2 Wastewater Plan A3

This plan is provided by Anglian Water pursuant its obligations under the Water Industry Act 1991 sections 198 or 199. It must be Foul Sewer [email protected] used in conjunction with any search results attached. The information on this plan is based on data currently recorded but position Surface Sewer must be regarded as approximate. Service pipes, private sewers and drains are generally not shown. Users of this map are strongly Outfall* Sewage Treatment Works advised to commission their own survey of the area shown on the plan before carrying out any works. The actual position of all S16523P apparatus MUST be established by trial holes. No liability whatsoever, including liability for negligence, is accepted by Anglian Water Combined Sewer for any error or inaccuracy or omission, including the failure to accurately record, or record at all, the location of any water main, Final Effluent Inlet* discharge pipe, sewer or disposal main or any item of apparatus. This information is valid for the date printed. This plan is produced Public Pumping Station by Anglian Water Services Limited (c) Crown copyright and database rights 2018 Ordnance Survey 100022432.This map is to be Rising Main* used for the purposes of viewing the location of Anglian Water plant only. Any other uses of the map data or further copies is not permitted. This notice is not intended to exclude or restrict liability for death or personal injury resulting from negligence. Private Sewer* Manhole* Decommissioned Pumping Station Decommissioned Sewer* *(Colour denotes effluent type) Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Appendix C Topographical Survey

c Survey & Engineering Projects Ltd. 2019 Reproduction in whole or in part by any means is prohibited without the prior permission of Survey & Engineering Projects Ltd. T. (01695) 729835 F. (01695) 725566 W. www.sepsurvey.com E. [email protected]

PLAN GRID NORTH

File Name: S16523-T.dwg BS1

LEGEND

SEP1

NOTES: All levels relate to O.S (Newlyn) Datum, Established using network RTK. Survey plotted on a plane local grid, orientated to National Grid.

SEP2

SEP3 2 1

MEZ1

SHEET LAYOUT

X5 0 2m 4m 8m 12m 16m

SCALE BAR

REV DATE DESCRIPTION

SURVEY & ENGINEERING PROJECTS SEP4

Client Civic Engineers Carver's Warehouse 77 Dale Street Manchester M1 ZHG

Project Title Topographical Survey of Land at: Wolverton Agora Wolverton Milton Keynes MK12 5LD Sheet 1 of 2

Surveyed Drawn Checked B.Squires D.Wright R.Critchley

Scale Date Drawing Ref. No. Size Rev 1:200 Jan 19 S16523-T 01 A0 -- c Survey & Engineering Projects Ltd. 2019 Reproduction in whole or in part by any means is prohibited without the prior permission of Survey & Engineering Projects Ltd. T. (01695) 729835 F. (01695) 725566 W. www.sepsurvey.com E. [email protected]

PLAN GRID NORTH

File Name: S16523-T.dwg

LEGEND

BS2

BS1

NOTES: All levels relate to O.S (Newlyn) Datum, Established using network RTK. Survey plotted on a plane local grid, orientated to National Grid.

2 1

SHEET LAYOUT

0 2m 4m 8m 12m 16m

SCALE BAR

REV DATE DESCRIPTION

SURVEY & ENGINEERING PROJECTS

Client Civic Engineers Carver's Warehouse 77 Dale Street Manchester M1 ZHG

X3 Project Title Topographical Survey of Land at: Wolverton Agora Wolverton Milton Keynes MK12 5LD Sheet 2 of 2

Surveyed Drawn Checked B.Squires D.Wright R.Critchley

Scale Date Drawing Ref. No. Size Rev 1:200 Jan 19 S16523-T 02 A1 -- Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Appendix D Surface Water Calculations

Wolverton Agora, Milton Keynes \ 948-01 Appendix D – Surface Water Calculations

1. Introduction The purpose of the calculations is to establish the pre-development peak 1 in 1-year surface water run-off rate for a development Wolverton Agora, Milton Keynes and to calculate what attenuation volume will be required, if the surface water run-off from the proposed site were to be restricted to a 30% betterment of the pre-development 1 in 1-year rate, including 30% climate change.

2. Surface Water Catchment / Impermeable Areas

Overall Site Drainage Area = 13281m² / 1.32 ha

Pre-Development Impermeable Area = 13281m² / 1.32 ha (100% Impermeable)

Post-Development Impermeable Area = 11966m² / 1.197 ha (90% impermeable)

3. Surface Water Calculation Variables Data to calculate the pre-development 1 in 1-year surface water run-off rates and attenuation volumes are based on figures from the Flood Studies Report (FSR) data and Wallingford Procedure, which have been sourced from HR Wallingford.

The variables used to calculate the surface water run-off rates and required attenuation volumes are as follows:

M5 – 60 (mm) = 20.000

Ratio R = 0.4

Cv (Summer) = 0.750

Cv (Winter) = 0.840

Time of Entry = 5 minutes

Climate Change = 0 - Pre-Development

= 30% - Post Development

4. Pre-Development Peak 1 in 1 Year Surface Water Run-Off Based on the above variables, and calculations undertaken using a two-pipe simulated network within Micro Drainage computer software, the pre-development development surface water run-off rate is as follows:

Pre-Development 1 in 1-Year Rate - 169.1 l/s (15-minute critical storm)

Wolverton Agora, Milton Keynes \ 948-01 Appendix D – Surface Water Calculations

5. Post Development Restricted Surface Water Run-Off Rate The surface water from the proposed development is to be restricted by a flow control, in this case a vortex flow control devise will be used, to give:

Post Development SW Run-Off Rate = 118.4 l/s (169.1 l/s – 30% CC)

6. Surface Water Attenuation Volumes The surface water attenuation volumes have been calculated using the above variables and show that the attenuation volumes for the post development impermeable area of 1.197 ha, when restricted to 118.4 l/s.

1 in 100 Year Event + CC (30%) = 283.8m³ (118.4 l/s) Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Appendix E Drainage Strategy Plan

Standard Notes

This drawing is to be read in conjunction with all Community 1. STRATFORD ROAD Centre relevant Architect's and Engineer's drawings and the specification. GLYN SQUARE 2. This drawing should not be scaled.

Old Bath 1 Depot 3. All dimensions are to be verified by the contractor on House 4 site.

Shelter 5 4. All discrepancies should be reported to the C.A. prior

TCB 8 Car Park to the commencement of the works. 9 9a

79.2m Drawing Notes

13 14 1. This drawing has been based on the following; - Landscape GA layout (1068-URBED-Z0-00-M2-L- Hotel Landscape_Plan) provided by URBED on 10/09/2020

- Block A and C GA Layouts (WOL_MOL_A_ZZ_DR_100 Shelter 21 -P3 and WOL_MOL_C_ZZ_DR-103-P3) provided by MOLE on 19/07/2019

ESS - Block B,D,E and F GA layouts (WOL_MRA_B[/D/E/F]

_01_DR_AR_100) provided by Mikhail Riches on

22 25/07/2019

24 5

St Francis 21a de Sales Key

RADCLIFFE STREET Church RADCLIFFE STREET - DEVELOPMENT BOUNDARY Existing/Adopted Highways Wesley Methodist Hall - EXISTING UNITED UTILITIES COMBINED BLOCK C-2 WATER DRAINAGE 2 Church - EXISTING UNITED UTILITIES COMBINED 1 Catchment Area = 451m (3.4% of total site) CHURCH STREET Assumed 82.3% impermeable WATER DRAINAGE TO BE DIVERTED Proposed discharge = 4 l/s - EXISTING FW DRAINAGE - PRIVATE (allows 30% betterment) 3 - EXISTING FW DRAINAGE - PUBLIC BLOCK B-2 Storage Required = 10m T05 2 Storage via oversized pipe = 33m x 675mmØ T03 - EXISTING SW DRAINAGE - PRIVATE Catchment Area = 398m (3% of total site) 8 Assumed 81% impermeable 6 4 - EXISTING SW DRAINAGE - PUBLIC Proposed discharge = 3.5 l/s 2 T03 T05 (allows 30% betterment) 3 T01 Storage Required = 9m Ex. MH7011 - PROPOSED CW DRAINAGE DIVERSION New connection to public Anglian T01 T02 26 2 CL 80.80 Water Combined Water Sewer Storage via oversized pipe = 37m x 600mmØ T02 IL unknown 38 T01 3 T01 - PROPOSED CW MANHOLE 32 F Assumed IL 77.764

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA

BIKE x 2 RPA RPA

RPA RPA

RPA with unrestricted discharge rate RPA

RPA RPA

RPA to RPA RPA RPA

RPA RPA

PH RPA RPA

RPA RPA

T03 RPA RPA

RPA RPA

RPA 7 RPA

RPA RPA

RPA

RPA RPA

Connection and rate are subject RPA 40 RPA

RPA

RPA RPA

RPA - PROPOSED SW DRAINAGE RPA

RPA

RPA RPA

RPA 7 RPA

RPA

RPA RPA

RPA CL 81.668 RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA to agreement with Anglian Water RPA

RPA RPA

RPA BD 78.688 RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA Car Park RPA RPA RPA RPA RPA 42 RPA RPA RPA RPA RPA

IL 77.889 RPA T01 RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA IL unknown RPA

RPA

RPA RPA RPA - PROPOSED OVERSIZED SW PIPE RPA

RPA RPA RPA

RPA

RPA RPA RPA

D RPA RPA RPA

RPA

RPA RPA

Alighting / Layover / Charging RPA RPA

RPA 5 RPA

Ex. 600mm CW Sewer RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

T08 RPA

RPA RPA

5 RPA

RPA

RPA RPA

T04 RPA

RPA

RPA 42

RPA

RPA RPA

BIKE x 2 RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA RPA T08 RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA - PROPOSED SW MANHOLE WITH FLOW RPA RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA 44 RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA 43

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

ASHP RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

ASHP RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA 51

RPA RPA RPA

RPA CONTROL RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

T03 RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA T01 RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA

BIKE x 4 RPA RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

ASHP RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA ASHP RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA

RPA

RPA 50 RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA CL 81.960 RPA RPA

RPA RPA RPA

RPA T06 RPA RPA RPA

RPA

ASHP RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA T03 RPA 46 RPA

RPA RPA

RPA

RPA ASHP RPA

RPA BUS STOP CL 82.136 RPA RPA

RPA

RPA 2 RPA RPA

RPA

RPA RPA

IL 80.460 RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA - PROPOSED SW MANHOLE RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA T08 RPA RPA

RPA

RPA RPA 52 RPA

RPA

IL 80.049 RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

C RPA RPA New connection to public Anglian

RPA RPA RPA RPA

CL 81.000 RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA RPA 47 RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

54 RPA

RPA RPA RPA

RPA RPA

RPA 6*

T03 RPA

T06 RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

ASHP RPA RPA RPA

RPA

RPA RPA

56 RPA RPA

IL 79.800 RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA

5 RPA RPA ASHP T09 RPA

60 to 64 RPA RPA RPA RPA

RPA Lych Gate RPA

RPA RPA RPA RPA

RPA Water Combined Water Sewer RPA RPA

RPA

RPA RPA

T01 RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA 58 T04 RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

ASHP RPA

RPA RPA RPA

RPA - PROPOSED BACKDROP

RPA

RPA RPA

BIKE x 2 RPA

RPA

RPA RPA

RPA

RPA RPA

CL 82.070 7* RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

T07 RPA

RPA

RPA RPA

T07 RPA

RPA

RPA RPA

T01 RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA Proposed discharge rate - 82.1 l/s

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA

RPA

IL 80.070 RPA

RPA

Ex. 525mm CW Sewer RPA

RPA

T06 RPA

RPA

RPA RPA

T06 RPA

RPA RPA

BIKE x 4 RPA

RPA

RPA RPA

Storage RPA

RPA

RPA Connection and rate are subject

RPA

T09 RPA

RPA

RPA RPA

Loading Bay CL 80.940 RPA RPA

RPA

RPA RPA

RPA - PROPOSED ATTENUATION TANK

RPA

RPA RPA

18 RPA

RPA

B RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA IL 79.340 RPA RPA RPA

RPA RPA

RPA 16 RPA

RPA RPA

RPA RPA to agreement with Anglian Water

RPA RPA

RPA

RPA RPA

RPA

RPA T10 RPA RPA

RPA

RPA RPA

RPA

ASHP RPA

RPA

RPA CLRPA 82.136

RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA T07 RPA RPA RPA ASHP RPA 3 RPA RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA - BLOCK A-1 DRAINAGE AREA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

T06 RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA BD 80.032 RPA RPA RPA

RPA RPA RPA RPA RPA

RPA

RPA ST GEORGES WAY RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA IL 78.931 RPA

RPA RPA

RPA 55 RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA 12*

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

T06 RPA

ASHP RPA

4 RPA RPA

RPA

RPA RPA

RPA

RPA RPA

A RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

ASHP RPA

RPA

RPA RPA RPA

RPA

RPA - BLOCK A-2 DRAINAGE AREA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA BLOCK D ASHP

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

T06 RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA 2

RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA RPA RPA

5 RPA RPA

RPA RPA RPA

ASHP CL 82.830 RPA

RPA RPA RPA

RPA

RPA RPA

ASHP RPA RPA

RPA Area = 2759m (20.8% of total site)

RPA RPA

Proposed CW sewer diversion RPA RPA 5 RPA RPA

RPA RPA T06 RPA

13 RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

T06 IL 80.260 RPA

T10 RPA

RPA

RPA RPA

T06 RPA

RPA

RPA RPA

CL 82.830 RPA

RPA - BLOCK B-1 DRAINAGE AREA

RPA

RPA RPA

RPA Assumed 84% impermeable RPA

RPA RPA

Subject to agreement with RPA

RPA

RPA RPA

IL 80.081 RPA

RPA

RPA RPA

T09 RPA

RPA

RPA RPA

T08 RPA

RPA

RPA RPA

RPA Proposed discharge = 24.6 l/s

RPA

Anglian Water RPA

RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

T06 RPA RPA

RPA RPA RPA RPA

RPA RPA T08 RPA

RPA RPA

RPA T06 RPA

RPA RPA

ASHP RPA 1:13 RPA

RPA RPA

RPA - BLOCK B-2 DRAINAGE AREA RPA

RPA

RPA ASHP RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

T08 RPA RPA RPA RPA (allows 30% betterment) RPA RPA

RPA RPA RPA 15 RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA T11 RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA Ex. 400mm CW Sewer RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

ASHP RPA RPA RPA RPA RPA 3 RPA

RPA

RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA RPA RPA

RPA

RPA RPA ASHP RPA RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA Storage Required = 59m

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA 3 RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA BD2

RPA RPA RPA RPA

RPA RPA

RPA

RPA New connection to public Anglian RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA 5

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

NEXTBIKE x10 RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA

RPA

RPA - BLOCK C-1 DRAINAGE AREA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA 3 RPA

RPA RPA

B. DOCK RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA

RPA RPA Storage Tank Dimensions = 16 x 4 x 1m RPA

BD1 RPA RPA RPA

RPA RPA

CL 82.888 RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA T06 RPA

RPA RPA RPA

Water Combined Water SewerRPA RPA RPA

43*RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA CL 83.060 RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

CL 83.060 RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

IL 80.094 RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA IL 81.053

RPA (incl. 95% VOIDS)

RPA

TG3 RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

IL 79.541 RPA

RPA RPA

RPA

RPA CL 81.150 RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

Proposed discharge rate - 28.2 l/s RPA

RPA RPA

RPA Ex. MH7011 RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA - BLOCK C-2 DRAINAGE AREA RPA

RPA

RPA RPA RPA

RPA 6

RPA

RPA RPA RPA

RPA RPA

RPA CL 83.060 RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA 44* RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

IL 79.150 CL 82.830 RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA T01

RPA

RPA RPA RPA RPA

CL 82.84RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

Connection and rate are subject IL 81.060 RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

BD1 80.069 RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA IL unknownRPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA CL 82.945 RPA

RPA

RPA RPA

3 RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA 29

RPA RPA RPA

RPA

RPA RPA RPA RPA

BD2 80.252 RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

T03 RPA

RPA RPA

RPA

RPA RPA

RPA Assumed IL 78.428

RPA

RPA RPA

to agreement with Anglian WaterRPA

RPA

RPA RPA

RPA

IL 79.376 RPA

RPA

RPA RPA

RPA BIKE x6 RPA

Ex. 500mm CW Sewer RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA - BLOCK D DRAINAGE AREA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

IL 79.226RPA

RPA

RPA RPA

RPA

RPA RPA

5 RPA RPA

RPA Church of

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

CL 83.060 RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

IL unknownRPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA BD 80.986 T03 23 Assumed IL 79.064 Ex. MH7006 IL 79.532 St George The Martyr T01 - EXISTING/ADOPTED HIGHWAY CL 81.150 CL 83.060 CL 81.62 BLOCK C-1 IL 79.128 BD 80.080 IL 78.80 Area = 1928m2 (14.5% of total site) IL 79.420 Proposed CW sewer diversion - PROPOSED RAIN GARDEN E Assumed 96% impermeable CEDAR LODGE DRIVE POTENTIAL SW STORAGE CAPACITY FOR Ex. 375mm CW Sewer Subject to agreement with HIGHWAYS RUNOFF

Proposed discharge = 17.2 l/s 1 79.9m ASHP Anglian Water

ASHP

ASHP ASHP (allows 30% betterment) - PROPOSED LANDSCAPED AREA ASHP 2 ASHP Manhole chamber to be 3 5 Storage Required = 42m

T11 5 coordinated with existing utilities

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

T05 RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA Storage Tank Dimensions = 15 x 3 x 1m RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA T11

RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA 4 RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA Development boundary, discharge rates &

RPA RPA RPA RPA Potential localised diversion may

RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA EV RPA RPA RPA

RPA RPA

RPA 25.09.20 P04 DC PM RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA attenuation volumes updated

RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA (incl. 95% VOIDS)

RPA RPA RPA

T11 RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA 12 RPA RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA be required RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA 03.09.19 P03 EMM PM RPA RPA RPA Issued for Information

RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA Sewer CW 375mm Ex. RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

T11 RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA BLOCK A-1 RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA 22 RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA RPA RPA

RPA 07.06.19 P02 EMM PM RPA RPA

RPA Issued for Information RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

EV RPA 2 RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA

Catchment Area = 2574m (19.4% of total site) RPA RPA RPA RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA 11.03.19 P01 EMM PM

RPA Issued for Information

RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA RPA RPA RPA

RPA RPA RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA 47 RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA

48 RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA

49 RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA Assumed 4.5% impermeable RPA RPA 1

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA Date Rev Description Drawn Chkd

RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA 3

RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA RPA

RPA RPA RPA 6 RPA

RPA RPA

RPA RPA RPA BUCKINGHAM STREET

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

CL 83.630 RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA

RPA RPA RPA Proposed discharge = 22.9 l/s RPA

RPA RPA RPA Cedar

RPA RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA

RPA RPA RPA RPA RPA RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA RPA RPA

RPA

RPA RPA

RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA RPA RPA RPA

RPA RPA

RPA RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA RPA 13

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

IL 80.140 RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA

RPA

RPA RPA RPA (allows 30% betterment) RPA

56 Lodge 3 23 CC

Storage Required = 55m 5 CC Storage Tank Dimensions68 = 29 x 2 x 1m (incl. 95% VOIDS)

2 to 16 to 2 MANCHESTER Carver's Warehouse, 77 Dale Street, Manchester, M1 2HG. Tel: 0161 228 6757 26

BLOCK A-2 BLOCK B-1 LONDON Reeds Wharf, 33 Mill Street, London SE1 2AX. Tel: 020 7253 2977 27 Bushfields 2 3 2 LEEDS Tower Works, Unit 02-01, Globe Road, Leeds, LS11 5QG. Tel: 0113 2025 130 Catchment Area = 967m (7.3% of total site) Catchment Area = 3031m (22.8% of total site) GLASGOW Gresham Chambers, 45 West Nile St, Glasgow, G1 2PT. Tel: 0141 370 1829

24 22

X: 481650 AssumedY: 241000 99% impermeable Assumed 84% impermeable www.civicengineers.com

Proposed discharge = 8.6 l/s Proposed discharge = 27 l/s 20 Project (allows18 30% betterment) (allows 30% betterment) 3 3 Storage Required = 21m 7 Storage Required = 65m Wolverton Storage via oversized pipe16 = 69m x 675mmØ TCB Storage Tank Dimensions = 23 x 3 x 1m The Rectory 8 Milton Keynes (incl. 95% VOIDS) 6 82.0m

Title Drainage Strategy General Arrangement

Status INFORMATION

Scale @ A1 Date Created Drawn Checked 1:500 Mar 19 EMM PM Project Number Originator Discipline Drawing Number Revision 948-01 CE C 0100 P04 Love Wolverton Agora, Milton Keynes \ 948-01 Flood Risk Assessment and Drainage Strategy

Appendix F Anglian Water Pre-Development Enquiry

Pre-Planning Assessment Report

Church Street, Wolverton and Greenleys

Pre-Planning Report Wednesday, June 13, 2018

Section 1: Proposed Development

Thank you for submitting a pre-planning enquiry. This has been produced for Civic Engineers. Your reference number is 00028300. If you have any questions upon receipt of this report, please contact the Pre-Development team on 0345 606 6087 Option 1 or email [email protected].

The response within this report has been based on the following information which was submitted as part of your application:

List of Planned Developments Type of Development No. Of Units C3 Dwellings 114 A1 Shops 4

The anticipated residential build rate is:

Year 2018 2019 2020 Build Rate 50 50 14

 The grid reference for the site is SP8168041084.

 The site currently does not have planning permission and is located on a brownfield site.

Pre-Planning Report Wednesday, 13 June 2018

Section 2: Assets Affected

Our records indicate that we have the following types of assets within or overlapping the boundary of your development site as listed in the table below.

Additionally, it is highly recommended that you carry out a thorough investigation of your proposed working area to establish whether any unmapped public or private sewers and lateral drains are in existence. We are unable to permit development either over or within the easement strip without our prior consent. The extent of the easement is provided in the table below. Please be aware that the existing water mains/public sewers should be located in highway or open space and not in private gardens. This is to ensure available access for any future maintenance and repair and this should be taken into consideration when planning your site layout.

Water and Used Water Easement Information Asset Type Pipe Size (mm) Total Easement Required (m)

Combined Sewer 600 Unknown

Surface Water Sewer 225 3.0 m either side of the centre line

Combined Sewer 375 Unknown

Combined Sewer 450 Unknown

Water Mains 150 3.0 m either side of the centre line

Public Foul Sewer 150 3.0 m either side of the centre line

Public Foul Sewer 225 3.0 m either side of the centre line

If it is not possible to avoid our assets then the water main/sewer may need to be diverted in accordance with Section 185 of the Water Industry Act (1991). We have a duty to divert our sewerage infrastructure if requested to do so although this would be at your expense. You will need to make a formal application if you would like a diversion to be considered. A copy of the section 185 diversion application form can be found at www.anglianwater.co.uk/developers

Due to the private sewer transfer in October 2011 many newly adopted public used water assets and their history are not indicated on our records. You also need to be aware that your development site may contain private water mains, drains or other assets not shown on our records. These are private assets and not the responsibility of Anglian Water but that of the landowner.

Pre-Planning Report Wednesday, 13 June 2018

Section 3: Water Supply

In examining the available capacity for your development site we assess the capacity for two categories of water main. These are:

Strategic – these are the potable water mains on our existing network which deliver water within an area to a large number of development sites often across a number of towns. The strategic provision of these water mains enables us to provide the cheapest solution across a large geographical area.

Local – these are nearby potable water mains that may be affected by the provision of water to the development resulting in the loss of water or water pressure to existing houses.

The cost of reinforcement and upgrades to our existing network, called “Network Reinforcements”, whether designed to address strategic or local capacity issues, are covered in the Zonal Charges section of this report.

We also consider what new infrastructure needs to be built to connect the development site to our existing network. This new infrastructure from (and including) the point of connection to our network is called “Site-Specific Works”.

Water Supply Network Your site will benefit from the strategic water main(s) as listed below. This strategic scheme has been designed to cater for the predicted growth in this area. All developments that benefit from this strategic water scheme will be required to make a contribution proportional to their flow demand. We have calculated your flow in the table below. More detail on the strategic costs are provided below in the costing section of this report.In addition, there is also insufficient capacity in the localised network to supply your site and therefore offsite local reinforcements are needed. Details of these costs are found at the end of this section of the report.

If you wish to proceed with the development then you will need to complete an application for a new supply. This is recommended to be done at the earliest opportunity as it could take a minimum of 12 months to install any offsite reinforcement works. The connection point for the site will be from the existing water main in Buckingham Street Wolverton.

The connection point for the site will be from the existing 150mm AC water main in Buckingham Street Wolverton at National Grid Reference SP8169141021.

Pre-Planning Report Wednesday, 13 June 2018

Water Infrastructure & Costs

In order to supply your site, the following upgrades are required:

Strategic Water Mains Based on

Old Stratford to Kiln Farm new main - 800mm ID. 2.507 l/s

Old Stratford Water Booster AMP7 upgrade 2.507 l/s

Estimated Local reinforcement Mains

Millers Way A5 crossing Offsite mains reinforcement is required of the existing 12in ST main on Millers Way which crosses the A5 comprising of 165m of 355mm HPPE SDR21. Start grid ref SP8077139740, end grid ref SP8092639786. Cost included in the Zonal Charge

As a result of the recent charging rules published by Ofwat, our charging regime has changed.

Your development site will be required to pay a Zonal charge for each new property connecting to our water supply network that benefit from Full planning permission. This covers all Network Reinforcement.

Payment of the Zonal charge must be made before premises are connected to our water supply network. More information on the Zonal charge can be found at www.anglianwater.co.uk/developers/charges

The Zonal charge consists of two elements. The first is called the ‘Fixed Element’ which is the same in nature to the Infrastructure charge applied prior to April 2018. The second is called the ‘Variable Element’ which may vary each financial year.

The elements are combined together to create the 2018/19 Zonal charge for Water:

Fixed Element £370.00 Variable Element £88.50

Pre-Planning Report Wednesday, 13 June 2018 In most circumstances zonal charges are raised on a standard basis of one charge per new connection (one for water and one for sewerage). However, if the new connection is to non-household premises, the fixed element is calculated according to the number and type of water fittings in the premises. This is called the “relevant multiplier” method of calculating the charge. Details of the relevant multiplier for each fitting can be found at our web-page: http://www.anglianwater.co.uk/developers/charges/

The total Zonal charge payable for your site for Water is:

Zonal charge per new No. Of Units Total amount payable connection - Water £458.50 114 £52,269.00

The estimated* Onsite Water Mains cost for your site is:

Estimated Onsite Water Mains

Onsite water mains costs £8,208.00 *A detailed cost breakdown will be provided on receipt of a formal application for a new water main.

In addition, you also have the ability to construct the onsite water mains under a self-lay agreement. In such cases, an Asset Payment is made by Anglian Water following commissioning and adoption of the assets. The Asset Payment is calculated as required in the Water Act 2003. For more information on the self-lay of water mains please see www.anglianwater.co.uk/developers/self-lay.

You will also need to budget for connection costs. Please note that we offer alternative types of connections depending on your needs and these costs are available in our annual charges booklet, which can be downloaded from www.anglianwater.co.uk/developers/charges.

Pre-Planning Report Wednesday, 13 June 2018 Section 4: Water Recycling Services

In examining the used water system we assess the ability for your site to connect to the public sewerage network without causing a detriment to the operation of the system. We also assess the receiving water recycling centre and determine whether the water recycling centre can cope with the increased flow and influent quality arising from your development.

Water Recycling Centre The foul drainage from the proposed development is in the catchment of Cotton Valley Water Recycling Centre, which currently has capacity to treat the flows from your development site. Anglian Water cannot reserve capacity and the available capacity at the water recycling centre can be reduced at any time due to growth, environmental and regulation driven changes.

Used Water Network Our assessment has been based on development flows connecting to the nearest foul water sewer of the same size or greater pipe diameter to that required to drain the site. The infrastructure to convey foul water flows to the receiving sewerage network is assumed to be the responsibility of the developer. Conveyance to the connection point is considered as Onsite Work and includes all work carried out upstream from of the point of connection, including making the connection to our existing network.

This connection point has been determined in reference to the calculated design flow using criteria from Sewers for Adoption (6th edition). On this basis, a 150mm internal diameter pipe is required to drain the development site.

Anglian water has assessed the impact of gravity flows from the planned development to the public foul sewerage network. We can confirm that this is acceptable as the foul sewerage system, at present, has available capacity for your site. The connection point will be to the nearest 600mm diameter sewer between manholes 6008 and 7103 in Church Street at a point best suited to the site layout, at National Grid Reference SP8172941111.

Surface Water Disposal Where a Brownfield site is redeveloped, no historic right of connection will exist, and any sewer connections will be treated as new. The site will be treated as if it was Greenfield and therefore discharge rate limited to the equivalent 1 in 1 year Greenfield rate. The Greenfield runoff for the site is calculated using the FEH method. A free Greenfield runoff estimation tool can be accessed on the UKSuDS website www.uksuds.com

Where the above is not practical, the Developer is asked to calculate the existing Brownfield rates based on the existing roof areas. The discharge rate from the development will be limited to the equivalent 1 in 1 year rate, or an appropriate rate as agreed by Anglian Water.

Pre-Planning Report Wednesday, 13 June 2018 In both circumstances, Anglian Water will assess the capacity of the public sewers and upon meeting the above policy principles, advise and make recommendations on the proposed development and or new connection.

We have examined your development site for available surface water discharge options. It is our understanding that the evidence to confirm your compliance with the surface water hierarchy is not currently available. However once the evidence has been confirmed, then a connection point may be made to the combined sewer in Church Street between manholes 6008 and 7103 at a point best suited to the site layout, at National Grid Reference SP8172941111 at a discharge rate of 5.00l/s. This is subject to evidence being provided to demonstrate that the site currently discharges surface water to this sewer.

It is your responsibility to provide the evidence to confirm that all alternative methods of surface water disposal have been explored and these will be required before your connection can be agreed. This is subject to satisfactory evidence which shows the surface water management hierarchy as outlined in Building Regulations Part H has been explored. This would encompass the results fromthe site specific infiltration testing and/or confirmation that the flows cannot be discharged to a watercourse.

Anglian Water's surface water policy follows the Surface Water hierarchy, outlined in Part H of the Building Regulations. Should your assumptions or evidence change then an alternative solution, connection point or flow rate may be required. You are therefore advised to update Anglian Water with the key supporting evidence at your earliest convenience.

It is your responsibility to provide the evidence to confirm that all alternative methods of surface water disposal have been explored and these will be required before your connection can be agreed. This is subject to satisfactory evidence which shows the surface water management hierarchy as outlined in Building Regulations Part H has been explored. This would encompass the results from the site specific infiltration testing and/or confirmation that the flows cannot be discharged to a watercourse.

As you may be aware, Anglian Water will consider the adoption of SuDs provided that they meet the criteria outline in our SuDs adoption manual. This can be found on our website at http://www.anglianwater.co.uk/developers/suds.aspx. We will adopt features located in public open space that are designed and constructed, in conjunction with the Local Authority and Lead Local Flood Authority (LLFA), to the criteria within our SuDs adoption manual. Specifically, developers must be able to demonstrate:

Pre-Planning Report Wednesday, 13 June 2018 1. Effective upstream source control, 2. Effective exceedance design, and 3. Effective maintenance schedule demonstrating than the assets can be maintained both now and in the future with adequate access.

If you wish to look at the adoption of any SuDs then an expression of interest form can be found on our website at: http://www.anglianwater.co.uk/developers/suds.aspx

The proposed method of surface water disposal is not relevant to Anglian Water; we suggest that you contact the relevant Local Authority, Lead Local Flood Authority, the Environment Agency or the Internal Drainage Board, as appropriate.

Trade Effluent We note that you do not have any trade effluent requirements. Should this be required in the future you will need our written formal consent. This is in accordance with Section 118 of the Water Industry Act (1991).

Used Water Budget Costs As a result of the recent charging rules published by Ofwat, our charging regime has changed. Your development site will be required to pay a Zonal charge for each new property connecting to the public sewer that benefits from Full planning permission.

Payment of the Zonal charge must be made before premises are connected to the public sewer. More information on the Zonal charge can be found at www.anglianwater.co.uk/developers/charges

The elements are combined together to create the 2018/19 Zonal charge for Sewerage:

Fixed Element £370.00 Variable Element £101.00

The total Zonal charge payable for your site for Sewerage is:

Zonal charge per new No. Of Units Total amount payable connection - Sewerage £471.00 114 £53,694.00

It has been assumed that the onsite used water network will be provided under a section 104 Water Industry Act application.

Pre-Planning Report Wednesday, 13 June 2018 It is recommended that you also budget for connection costs. Please note that we offer alternative types of connections depending on your needs and these costs are available at our website.

Pre-Planning Report Wednesday, 13 June 2018 Section 5: Map of Proposed Connection Points

Water Connection Point

Pre-Planning Report Wednesday, 13 June 2018 Surface Water Connection Point

Pre-Planning Report Wednesday, 13 June 2018

Section 6: Useful Information

Water Water Industry Act – Key Water Sections: • Section 41: This provides you with the right to requisition a new water main for domestic purposes to connect your site to the public water network. • Section 45: This provides you with the right to have a connection for domestic purposes from a building or part of a building to the public water main. • Section 51A - E: This provides you with the right to provide the water main or service connection yourself and for us to vest them into our company.  Section 55: This applies where you request a supply of water for non domestic purposes. • Section 185: This provides you with the right to make a reasonable request to have a public water main, sewer or public lateral drain removed or altered, at your expense. Details on how to make an application and the s185 form is available on our website at http://www.anglianwater.co.uk20/developers or via our Developer Services team on 08457 60 66 087.

Details on how you can make a formal application for a new water main, new connection or diversion are available on from our Developer Services team on 08457 60 66 087 or via our website at www.anglianwater.co.uk/developers

If you have any other queries on the rights to requisition or connect your housing to the public water and sewerage infrastructure then please contact our developer services team at: Developer Services, Anglian Water, PO Box 495, Huntingdon, PE29 6YY or Telephone: 0845 60 66 087 or Email: [email protected]

Water pressure and flow rate: The water pressure and consistency that we must meet for your site is laid out in the Water Industry Act (1991). This states that we must supply a flow rate of 9 litres per minute at a pressure of 10 metres of head to the external stop tap. If your water pressure requirements exceed this then you will need to provide and maintain any booster requirements to the development site.

Self Lay of Water Mains: A list of accredited Self Lay Organisations can be found at www.lloydsregister.co.uk/schemes/WIRS/providers-list.aspx.

Used Water

Water Industry Act – Key Used Water Sections: • Section 98: This provides you with the right to requisition a new public sewer. The new public sewer can be constructed by Anglian Water on your behalf. Alternatively, you can construct the sewer yourself under section 30 of the Anglian Water Authority Act 1977.

Pre-Planning Report Wednesday, 13 June 2018 • Section 102: This provides you with the right to have an existing sewerage asset vested by us. It is your responsibility to bring the infrastructure to an adoptable condition ahead of the asset being vested. • Section 104: This provides you with the right to have a design technically vetted and an agreement reached that will see us adopt your assets following their satisfactory construction and connection to the public sewer. • Section 106: This provides you with the right to have your constructed sewer connected to the public sewer. • Section 185: This provides you with the right to have a public sewerage asset diverted.

Details on how to make a formal application for a new sewer, new connection or diversion are available on our website at www.anglianwater.co.uk/developers or via our Developer Services team on 08457 60 66 087.

Sustainable Drainage Systems: Many existing urban drainage systems can cause problems of flooding, pollution or damage to the environment and are not resilient to climate change in the long term. Therefore our preferred method of surface water disposal is through the use of Sustainable Drainage Systems (SuDS). SuDS are a range of techniques that aim to mimic the way surface water drains in natural systems within urban areas. For more information on SuDS, please visit our website at http://www.anglianwater.co.uk/developers/suds.aspx . We also recommend that you contact the Local Authority and Lead Local Flood Authority (LLFA) for the area to discuss your application.

Private Sewer Transfers: Sewers and lateral drains connected to the public sewer on the 1 July 2011 transferred into Water Company ownership on the 1 October 2011. This follows the implementation of the Floods and Water Management Act (FWMA). This included sewers and lateral drains that were subject to an existing Section 104 Adoption Agreement and those that were not. There were exemptions and the main non- transferable assets were as follows:

• Surface water sewers and lateral drains that did not discharge to the public sewer, e.g. those that discharged to a watercourse. • Foul sewers and lateral drains that discharged to a privately owned sewage treatment/collection facility. • Pumping stations and rising mains will transfer between 1 October 2011 and 1 October 2016.

The implementation of Section 42 of the FWMA will ensure that future private sewers will not be created. It is anticipated that all new sewer applications will need to have an approved section 104 application ahead of a section 106 connection.

Encroachment: Anglian Water operates a risk based approach to development encroaching close to our used water infrastructure. We assess the issue of encroachment if you are

Pre-Planning Report Wednesday, 13 June 2018 Water Connectionplanning to build within 400 metres of a water recycling centre or, within 15 metres to Point 100 metres of a pumping station. We have more information available on our website at http://anglianwater.co.uk/developers/encroachment.aspx

Locating our assets: Maps detailing the location of our water and used water infrastructure including both underground assets and above ground assets such as pumping stations and recycling centres are available from www.digdat.co.uk. All requests from members of the public or non-statutory bodies for maps showing the location of our assets will be subject to an appropriate administrative charge. We have more information on our website at: www.anglianwater.co.uk/developers/our-assets/

Summary of charges: A summary of this year’s charges can be found at http://www.anglianwater.co.uk/developers/charges/

Disclaimer: The information provided within this report is based on the best data currently recorded, recorded within the last 12 months or provided by a third party. The position must be regarded as approximate. If there is further development in the area or for other reasons the position may change.

The accuracy of this report is therefore not guaranteed and does not obviate the need to make additional appropriate searches, inspections and enquiries. You are advised therefore to renew your enquiry should there be a delay in submitting your application for water supply/sewer connection to re-confirm the situation. The responses made in this report are based on the presumption that your proposed development obtains planning permission. Whilst this report has been prepared to help assess the viability of your proposal, it must not be considered in isolation. Anglian Water supports the plan led approach to sustainable development that is set out in the National Planning Policy Framework (NPPF). As a spatial planning statutory consultee, we assist planning authorities in the preparation of a sustainable local plan on the basis of capacity within our water and water recycling (formerly referred to as wastewater) infrastructure. Consequently, any infrastructure needs identified in this report must only be considered in the context of up to date, adopted or emerging local plans. Where local plans are absent, silent or out of date these needs should be considered against the definition of sustainability set out in the NPPF as a whole.

No liability whatsoever including liability for negligence is accepted by Anglian Water Services Limited for any error or inaccuracy or omission including the failure to accurately record or record at all, the location of any water main, discharge pipe, sewer, or drain or disposal main or any item of apparatus.

Pre-Planning Report Wednesday, 13 June 2018

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