PLYMOUTH ROAD, PLYMPTON, PLYMOUTH. FLOOD RISK ASSESSMENT. On Behalf of. Lidl UK.

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1 PLYMOUTH ROAD, PLYMPTON, PLYMOUTH. FLOOD RISK ASSESSMENT On Behalf of Lidl UK Date: Our Ref: JER6216 RPS 34 Lisbon Street Leeds West Yorkshire LS1 4LX Tel: (0)

2 Quality Management Prepared by: Jonathan Morley Senior Consultant Reviewed by: Dr Paul Hardwick Associate Authorised by: Dr Paul Hardwick Associate Date: Revision: Project Number: Document Reference: JER6216 JER Lidl, Plymouth Rd, Plympton, Plymouth COPYRIGHT RPS The material presented in this report is confidential. This report has been prepared for the exclusive use of Lidl UK and shall not be distributed or made available to any other company or person without the knowledge and written consent of Lidl UK or RPS. JER6216 i rpsgroup.com/uk

3 1 This report contains only that available factual data for the site which was obtained from the sources described in the text. These data were related to the site on the basis of the location information made available to RPS and its sub-consultants by the client. 2 The assessment of the site is based on information supplied by the client and on-site inspections by RPS and its sub-consultants. Relevant information was also obtained from other sources. 3 The report reflects both the information provided to RPS and its sub-consultants in documents made available for review and the results of observations and consultations by RPS staff and its sub-consultants. 4 Where data have been supplied by the client or other sources, including that from previous site audits or investigations, it has been assumed that the information is correct but no warranty is given to that effect. While reasonable care and skill has been applied in review of this data no responsibility can be accepted by RPS for inaccuracies in the data supplied. 5 This report is prepared and written in the context of the proposals stated in the introduction to this report and its contents should not be used out of context. Furthermore new information, developing practices and changes in legislation may necessitate revised interpretation of the report after its original submission. 6 The copyright in the written materials shall remain the property of the RPS Company but with a royalty-free perpetual licence to the client deemed to be granted on payment in full to the RPS Company by the client of the outstanding amounts. 7 The report is provided for sole use by the addressees and is confidential to them and their professional advisors. No responsibility whatsoever for the contents of the report will be accepted to any person other than the Addressees. JER6216 ii rpsgroup.com/uk

4 Amendment Record Revision No. Date Reason for Change Authors Initials JER6216 iii rpsgroup.com/uk

5 Executive Summary S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 RPS has undertaken a Flood Risk Assessment (FRA) in accordance with the requirements of the National Planning Policy Framework (NPPF) and Planning Practice Guidance for the proposed commercial development off Plymouth Road, Plympton, Plymouth. The entire development site is presently located within EA and SFRA Flood Zone 1 classified with a low probability of flooding from fluvial sources. There is no historical evidence of flooding at the site. The site is at negligible to low susceptibility to surface water flooding. The susceptibility to groundwater flooding is low. The risk of flooding from infrastructure failure is considered to be low. The risk of flooding from reservoir failure has been assessed as low. The commercial elements of the proposed development are defined as less vulnerable in the NPPF and Planning Practice Guidance, and are deemed appropriate for the present flood zone and the zone including climate change. As development types have been steered to sequentially appropriate areas there is no requirement for either a Sequential or Exceptions Test. There will be a 2,591 m 2 (0.259ha) or 21% decrease in low permeability cover. Surface runoff will need to be controlled at an agreed runoff rate. This FRA and supporting documentation shows that the proposed development at this location meets the requirements of the NPPF and associated Planning Practice Guidance. JER6216 iv rpsgroup.com/uk

6 Contents 1 Scope of Work Background Project Scope Source of Information Introduction Legislation and Guidance Climate Change Site Setting Site Location Existing Development Proposed Development Fluvial and Tidal Flooding Flood defences Flooding from rising / high groundwater Source Protection Zones Reservoir Failure Assessment Sewer/Water Main Failure Assessment Surface water flooding Historical flood events Flood Risk Vulnerability Classification Current Flood Risk Drainage Surface Water and Drainage Legislative background Existing Drainage System Current Runoff Rate Proposed Runoff Rate Runoff Calculations Summary and Conclusions Summary Flood Risk Conclusion...15 JER6216 v rpsgroup.com/uk

7 Tables and Figures Tables Table 1- Information sources consulted during preparation of the report Table 2 - Flood Risk Vulnerability and Flood Zone Compatibility...11 Table 3 - Runoff characteristics Figures Figure 1 - EA reservoir flood map Figure 2 - EA surface water map JER6216 vi rpsgroup.com/uk

8 Drawings Drawing 1 Drawing 2 Drawing 3 Drawing 4 Drawing 5 Site location plan Existing site layout Proposed site layout Environment Agency Flood Zones Plymouth City Council SFRA Mapping JER6216 vii rpsgroup.com/uk

9 Appendices Appendix 1 RPS Flood Risk Assessment May 2014 Appendix 2 Correspondence Environment Agency and Plymouth City Council Appendix 3 Topographical Survey Appendix 4 Drainage plans Appendix 5 WinDes calculations JER6216 viii rpsgroup.com/uk

10 1 Scope of Work 1.1 Background At the request of Lidl UK, RPS Planning and Development Ltd (RPS) has updated a sitespecific Flood Risk Assessment (FRA) produced in May 2014 (Appendix 1) to support a planning application for the construction of a commercial use development site on an rectangular shaped parcel located off Plymouth Road, Plympton, Plymouth Planning consent was provided for the initial proposal in 20 th January 2015, Ref 14/01281/FUL. However, Lidl has now instructed RPS to revise the FRA to take into account alterations to the proposed development layout This FRA will form part of the planning application Developments that are designed without regard to flood risk may endanger lives, damage property, cause disruption to the wider community, damage the environment, be difficult to insure and require additional expense on remedial works. Current guidance on development and flood risk identifies several key aims for a development to ensure that it is sustainable in flood risk terms. These aims are as follows: The development should not be at a significant risk of flooding and should not be susceptible to damage due to flooding; The development should not be exposed to flood risk such that the health, safety and welfare of the users of the development, or the population elsewhere, is threatened; Normal operation of the development should not be susceptible to disruption as a result of flooding; Safe access to and from the development should be possible during flood events; The development should not increase flood risk elsewhere; The development should not prevent safe maintenance of watercourses or maintenance and operation of flood defences; The development should not be associated with an onerous or difficult operation and maintenance regime to manage flood risk. The responsibility for any operation and maintenance required should be clearly defined; Future users of the development should be made aware of any flood risk issues relating to the development; The development design should be such that future users will not have difficulty obtaining insurance or mortgage finance, or in selling all or part of the development, as a result of flood risk issues; The development should not lead to degradation of the environment; and The development should meet all of the above criteria for its entire lifetime, including consideration of the potential effects of climate change. JER rpsgroup.com/uk

11 1.1.5 The FRA is undertaken with due consideration of these sustainability aims The key objectives of the FRA are: To assess the flood risk to the proposed development and to demonstrate the feasibility of appropriately designing the development such that any residual flood risk to the development and users would be acceptable; To assess the potential impact of the proposed development on flood risk elsewhere and to demonstrate the feasibility of appropriately designing the development such that the development would not increase flood risk elsewhere; and To satisfy the requirements of NPPF and Planning Practice Guidance which require FRAs to be submitted in support of planning applications for development over 1 ha in area. 1.2 Project Scope This FRA has the following structure: Section 2 identifies the sources of information that have been consulted in preparation of the report. Section 3 provides a hydrological review off the site and undertakes a flood risk assessment of the proposed development scheme. Section 4 describes the sites vulnerability status in line with the NPPF and Planning Practice Guidance. Section 5 describes the flood risk management measures that should be applied to the site, where required. Section 6 provides a summary and conclusion to the report. JER rpsgroup.com/uk

12 2 Source of Information 2.1 Introduction Table 1 below lists the information sources consulted during preparation of this report. Table 1- Information sources consulted during preparation of the report. Data Source Notes Site setting and hydrology. Geology. Environment Agency. Local Planning Authority (LPA). Water Utility Company. Flood Risk Assessment and Planning Guidance. Reports. OS Mapping 1: Sheet 201: Plymouth and Launceston. Environment Agency. BGS 1: Sheet 348: Plymouth EA data holdings, customer service and engagement team. Plymouth City Council. South West Water. National Planning Policy Framework (NPPF). Planning Practice Guidance. Plymouth City Council SFRA, Level 1. Plymouth City Council SFRA, Level 2. Plymouth City Council, Plympton SFRA, Level 2. Environment Agency, Tamar Catchment Flood Management Plan. Plymouth City Council Preliminary Flood Risk Assessment Report. Area information, rivers and other watercourses, general site environs, built environment, catchment Information. Site and area geology. Current flood risk, local flood defences, flood levels, supplementary geology and groundwater information. Flood Zoning Local Development Framework. Water and sewerage assets in the vicinity of the site. Flood zoning for the site as used by the EA in England. Plymouth City Council, Plymouth Level 1 Strategic Flood Risk Assessment, July Plymouth City Council, Plymouth Level 2 Strategic Flood Risk Assessment, January Plymouth City Council, Plymouth Strategic Flood Risk Assessment Level 2 Plympton, May Environment Agency, Tamar Catchment Flood Management Plan, Summary Report June Plymouth City Council, Preliminary Flood Risk Assessment Report, 10 th June JER rpsgroup.com/uk

13 2.2 Legislation and Guidance Plymouth Core Strategy , adopted April The document sets out detailed planning policies and proposals for Plymouth City Council The Core Strategy is a strategic document providing broad guidance on the scale and distribution of development and the provision of supporting infrastructure. It contains higher level policies for delivering the spatial vision, guiding broad patterns of development and constraint. It also contains policies setting out the criteria to be taken into account by the Local Planning Authority in determining proposals for development and the use of land and buildings The policies relevant to hydrology and flood risk are outlined below; Policy CS20 - Sustainable Resource Use The Council will actively promote development which utilises natural resources in as an efficient and sustainable a way as possible. This will include: Meeting high water efficiency standards, and incorporating new technologies to recycle and conserve water resources. Policy CS21 - Flood Risk The Council will support development proposals that avoid areas of current or future flood risk, and which do not increase the risk of flooding elsewhere. This will involve a risk based sequential approach to determining the suitability of land for development. Development in high risk flood areas will only be permitted where it meets the following prerequisites: 1) It can be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk. 2) The development should be on previously developed land; if not, there must be no reasonable alternative sites on developable previously developed land. 3) A flood risk assessment has demonstrated that the development will be safe, without increasing flood risk elsewhere In addition development will be required to incorporate Sustainable Drainage Systems (SuDS) to manage surface water drainage Climate Change The effects of future climate change over the next few decades are predicted to result in milder wetter winters and hotter drier summers in the UK (UKCP09). An increased frequency of heavy, intense precipitation leading to increased peak river flows in combination with rising sea levels will have a major impact on the potential for future flooding. The UK Climate Projections (UKCP) project provides advice on indicative sensitivity ranges for the predicted impacts of climate change. Based on a high emissions scenario for the South West region of England, sea JER rpsgroup.com/uk

14 levels may be up to m higher in 2080 than in 1990, and winter mean precipitation intensity could be up to 31% higher than current levels in The Planning Practice Guidance to the NPPF notes that peak river flow could be 30% higher than current levels For the purposes of this report the Planning Practice Guidance 30% climate change allowance has been adapted for use in the development attenuation calculations. JER rpsgroup.com/uk

15 3 Site Setting 3.1 Site Location The site is located on the Erril Retail Park at NGR , 56510, approximately 5 km east of Plymouth City centre. The site is bordered to the north by the B3416 and to the south by a rail line with commercial units of the Valley Road Industrial Estate beyond (Drawing 1) Access to the site is gained via Cot Hill road. 3.2 Existing Development The site (Drawing 2) consists of a rectangular shaped parcel of land covering c.1.25 ha encompassed a vacant single storey warehouse style building, previously utilised as a bowling alley, which has recently been demolished. The remainder of the site is under hardstanding as surface car parking and also landscaping. The site is characterised by the following footprints: Building 4,264 m 2 ; Hardstanding 4,611 m 2 ; and Landscaping 3,603 m The ground falls from approximately 5.8 maod on the northern edge of the site to approximately 5.4 maod along the southern boundary. 3.3 Proposed Development It is understood that the application is for the development of a commercial facility comprising; Retail food store (2,544 m 2 ); Car parking and associated facilities (3,659 m 2 ); and Landscaping and permeable surfacing (6,249 m 2 ) The application includes for a new vehicular exit from the site onto Plymouth Road, and for the existing access/egress onto Cot Hill to be changed to allow for left in vehicle movements only The proposed site layout plan can be found in Drawing Fluvial and Tidal Flooding The closest watercourse to the proposed development is Tory Brook, which flows westerly in an open channel immediately north of the site. The Brook joins the northward flowing River Plym c.800 m to the west of the site Long Brook, a further tributary of the River Plym flows in a westerly direction c.200 m to the south of the site There are no other significant water features within 500 m of the proposed development. JER rpsgroup.com/uk

16 3.4.4 The Environment Agency s (EA) flood map (Drawing 4) indicates that the site lies within Flood Zone 1 and therefore has a low probability (less than 1 in 1,000 years) annual probability of flooding EA Flood Hazard Mapping (Appendix 2) shows the flood extents for a 1 in 100, 1 in 100 plus climate change and a 1 in 1,000 year event should a breach in flood defence occur. During all the modelled events the proposed application site is shown to be flood free The EA also provided modelled flood levels extracted from their Plympton Model The closest modelled in-channel node to the site (TB-00955b.1) located in Tory Brook recorded a 1 in 1,000 year flood level of 4.77 maod (Appendix 2). A comparison against the site surface level (Appendix 3) indicates that the site is located over 1 m higher that the modelled flood level and is therefore at low risk of fluvial flooding during a 1 in 1,000 year event. The site is also not subject to flooding from the watercourse to the south Plymouth City Council SFRA mapping (2010) also shows that that the site is located beyond the 1 in 100 year flood extents including climate change. The model generated to inform the SFRA flood extents also included a complete blockage of the Cot Hill road culvert c.230 m southwest of the site. 3.5 Flood defences EA and Plympton SFRA mapping shows a stretch of flood defences on the right and left banks of Tory Brook. The defences comprise a mix of raised and maintained channel defences which stretch for the entire length of the Brook from junction of Newnham Road and Torbridge Road to the Brooks confluence with the River Plym EA and SFRA records specify that the flood defences are privately maintained providing a 1 in 50 year standard of flood protection with a downstream crest level of 5.78 maod and upstream crest of 6.72 maod. The EA has assigned the defences with a Condition Grade 3 or fair rating. 3.6 Flooding from rising / high groundwater BGS online mapping (Accessed June 2014) indicates that the site is underlain by Superficial Deposits comprising river alluvium (sands silts and clays). British Geological Survey (BGS) bedrock mapping (sheet 348 Plymouth) shows that the superficial deposits below the site are underlain by Upper Devonian Slates comprising metamorphosed sedimentary mudstones and subordinate fine to medium grained sandstones and siltstones. The Wearde Sandstone member sub crops to the west and may extend below site but this is not certain The slates are classified by the EA under the Water Framework Directive as a Secondary A Aquifer, defined as permeable layers 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. These are generally aquifers formerly classified as minor aquifers. JER rpsgroup.com/uk

17 3.6.3 Although there are considerable alluvial deposits the EA note that there is no evidence of groundwater issuing at the surface in the area around the site. However, the watercourse that runs adjacent to the site is likely to be in hydraulic continuity with groundwater in the bedrock No groundwater levels within the immediate site area have been made available Based on the information outlined above the potential for groundwater flooding is considered to be low to moderate. 3.7 Source Protection Zones EA mapping shows the site is not located within a Source Protection Zone (SPZ). 3.8 Reservoir Failure Assessment EA mapping shows that the site is at risk of reservoir flooding from a complete failure of the dam at Burrator reservoir, NGR , The EA mapping shows the largest area that might be flooded following complete failure. Consequently it is unlikely that any actual flood would be this large. Moreover the EA state that reservoir flooding is extremely unlikely and UK reservoir safety legislation ensures that reservoirs are well maintained and inspected. Site Figure 1 - EA reservoir flood map. JER rpsgroup.com/uk

18 3.9 Sewer/Water Main Failure Assessment South West Water asset plans (Appendix 4) show the following drainage assets located within and in the near vicinity of the site: 450 mm Public Sewer crossing the western edge of the site conveying flows southward; and 500 mm surface water pipe running immediately adjacent to the western boundary of the site No cover levels or invert levels for the drainage assets have been provided The sewers will have been designed to industry standards (e.g. Sewers for Adoption ) however; the most common causes of flooding from sewers are; inadequate flow capacity, blockages, pumping station failures, burst water mains, water inflow from rivers or the sea, tide locking, siltation, fats/greases, and sewer collapse. Should any of these events occur there is a risk of flooding by surcharge where the flood is in excess of the sewer capacity (usually 1 in 30 year event or greater) Under the DG 5 register requirements all water companies are obliged to keep a record of properties that have been affected by sewer flooding. The Plympton SFRA mapping, which includes DG5 register information, indicates that the site has not been affected by flooding from artificial sources Taking into account the above and absence of any historical sewer flooding the overall risk of flooding via artificial drainage system to the site has been assessed to be low Surface water flooding EA surface water flood mapping (Figure 2 below) indicates that the majority of the site is at very low risk. Two localised areas of the site are shown to be at low risk of surface water flooding defined as areas with a probability of flooding of between 1 in 1,000 (0.1%) and 1 in 100 (1%) Overall, the site is assessed as of negligible to low susceptibility to surface water flooding. JER rpsgroup.com/uk

19 Site Figure 2 - EA surface water map Historical flood events The EA has provided details of a number of historical flood events that affected the Plympton area. The EA historical flood mapping (Appendix 2) and extents specific to an extreme event in 2012 indicates that the site has always been flood free No historical flood information was provided in the Plympton SFRA (2010). JER rpsgroup.com/uk

20 4 Flood Risk Vulnerability Classification In accordance with the Flood Risk Vulnerability Classification in Table 2 of the Planning and Practice Guidance Flood Risk and Coastal Change, a commercial facility is classified as a Less Vulnerable development in flood risk terms Table 3 of Planning Practice Guidance (Table 2 of this report) indicates that Less Vulnerable uses are appropriate for locations in Flood Zone 1. Table 2 - Flood Risk Vulnerability and Flood Zone Compatibility Flood Risk Vulnerability classification (see Table 3 of Planning Practice Guidance) Essential Infrastructure Water Compatible Highly Vulnerable More Vulnerable Less Vulnerable Zone 1 Yes Yes Yes Yes Yes Zone 2 Yes Yes Exception test required Yes Yes Zone 3a Zone 3b Functional Floodplain Exception test required Exception test required Yes No Exception test required Yes Yes No No No Key: Yes: Development is appropriate, No: Development should not be permitted. 4.2 Current Flood Risk The site is at low risk of fluvial flooding. The main flood risk is surface water flooding from direct rainfall on the site or upslope in the vicinity as indicated on the surface water flood map (Figure 2 in the main body of the report above). JER6216 rpsgroup.com/uk

21 5 Drainage 5.1 Surface Water and Drainage The sustainable management of surface water is an essential element of reducing future flood risk to the site and its surroundings Undeveloped sites generally rely on natural drainage to convey or absorb rainfall, the water soaking into the ground or flowing across the surface into watercourses The effect of development is generally to reduce the permeability of at least part of the site, which markedly changes the site s response to rainfall. Without specific measures to manage surface water the volume of water and peak flow rate are likely to increase. Inadequate surface water drainage arrangements can threaten the development itself and increase the risk of flooding to others Surface water arising from a developed site should as far as is practicable be managed in a sustainable manner to mimic the surface water flows arising from the site prior to the proposed development while reducing the risk of flooding at the site and elsewhere, taking climate change into account. 5.2 Legislative background Following the implementation of the Flood and Water Management Act 2010 local flood risk has become the responsibility of the Local Planning Authority. The Act places new duties on upper tier Councils, by designating them as Lead Local Flood Authorities (LLFAs) for the coordination of local flood risk management in their respective administrative areas The Act establishes a SuDS Approving Body (the SAB) at county or unitary local authority levels. The SAB has responsibility for the approval of proposed drainage systems in new developments and redevelopments. Approval must be given before any developer can commence construction. In order to be approved, the proposed drainage system would have to meet national standards for sustainable drainage The SAB is also responsible for adopting and maintaining SuDS which serve more than one property, which they have approved. The Highways Authorities will be responsible for maintaining SuDS in public roads to National Standards The National Standards set out the criteria by which the form of drainage appropriate to any particular site or development can be determined, as well as requirements for the design, construction, operation and maintenance of SuDS Additional guidance for the use of SuDS is provided via CIRIA and BRE in the following: C522 Sustainable Drainage Systems- Design Manual for England and Wales C523 Sustainable Drainage Systems- Best practice JER6216 rpsgroup.com/uk

22 C156 Infiltration Drainage Manual of Good practice BRE365 Soakaway design 5.3 Existing Drainage System Details of the current on site drainage system and discharge locations have not been made available. 5.4 Current Runoff Rate The site is presently covered by a mix of low permeability hardstanding, and more permeable soft landscaping. 5.5 Proposed Runoff Rate Section B7 of the National Standards for sustainable drainage systems (2011) indicates that for previously developed sites the flow rate discharged from the site must not exceed that prior to the proposed development for the: 1 in 1 year event; 1 in 30 year event; and 1 in 100 year event. 5.6 Runoff Calculations An assessment of the current and proposed runoff rates was undertaken to determine the surface water attenuation requirements for the site The rates of runoff were determined using the current industry best practice guidelines as outlined in the Interim Code of Practice for SuDS. The Defra/EA recommended methodology for sites up to 50 hectares in area is the Institute of Hydrology Report 124 method (IoH 124). The runoff rates were calculated using the Micro Drainage WinDes software suite The following parameters were incorporated into the existing site runoff calculations: Catchment Area: 1.25 ha (assume 30% permeable (landscaping) and 70% low permeable surfacing (hardstanding/buildings); Average Annual Rainfall (SAAR): 1309 mm/year; Soil: 0.300; Region No: The following parameters were incorporated into the proposed development runoff calculations: Catchment Area: 1.25 ha (assume 50% permeable (landscaping) and 50% low permeable surfacing (hardstanding/buildings)); Average Annual Rainfall (SAAR): 1309 mm/year; Soil: 0.300; JER6216 rpsgroup.com/uk

23 Region No: Table 3 summarises the results of the runoff calculations and shows that following the construction of the proposed development that there will be a decrease in surface water runoff from the site due to the c.20% reduction in low permeability area. Table 3 - Runoff characteristics. Annual Probability (Return Period, years) Current Runoff (l/s) Proposed Runoff (l/s) Reduction in runoff (l\s) 100% (1) QBAR urban % (30) % (100) % + Climate Change Note: 30% added to rainfall data to account for long-term climate change The WinDes calculation (Table 3) indicate that following construction of the proposed development there will be a reduction in the rate at which surface water is discharged from the Site as a consequence of the decrease in low permeable surfacing. Therefore, as the proposed development demonstrates a betterment in the surface water flow rates no additional surface water attenuation measures are required. JER6216 rpsgroup.com/uk

24 6 Summary and Conclusions 6.1 Summary A updated site-specific Flood Risk Assessment (FRA) in accordance with the NPPF and Planning Practice Guidance has been undertaken for the proposed c.1.25 ha commercial use development on Plymouth Road, Plympton, Plymouth. 6.2 Flood Risk EA and Plymouth City Council SFRA mapping shows that the site is entirely located in Flood Zone 1 and is consequently at low risk of flooding There is no historical evidence of flooding at the site The site is at negligible to low susceptibility to surface water flooding The susceptibility to groundwater flooding is low to medium The risk of flooding from infrastructure failure is considered to be low The risk of flooding from reservoir failure has been assessed as low The proposed development is appropriate for the present flood zone and the zone including climate change There is no requirement for either a Sequential or Exceptions Test There will be a c.20% decrease in low permeability cover. Surface runoff will need to be controlled at an agreed runoff rate It is advised that South West Water are consulted to ascertain available capacity and any recommendation incorporated into the development drainage design scheme. 6.3 Conclusion This FRA and supporting documentation illustrates that the proposed development is at low risk of flooding and appropriate to the location, meeting the requirements of the NPPF and Planning Practice Guidance. JER6216 rpsgroup.com/uk

25 References Amey, June Plymouth City Council, Preliminary Flood Risk Assessment Report. BGS (1977), 1:50,000 Geological Sheet 348 Plymouth and south-east Cornwall area, Keyworth Nottingham. Capita Symonds, May Plymouth City Council, Plymouth Strategic Flood Risk Assessment Level 2 Plympton, Final Report. CIRIA Report C532. Control of Water Pollution from Construction Sites. CIRIA Report C502 Environmental Good Practice on Site. CIRIA Report C697 (2007) The SuDS manual. Communities and Local Government, March National Planning Policy Framework. DEFRA, October Flood and Coastal Defence Appraisal Guidance FCDPAG4 Economic Appraisal Supplementary, Note to Operating Authorities Climate Change Impacts. DEFRA, December National Standards for sustainable drainage systems. Designing, constructing, operating and maintaining drainage for surface runoff. Environment Agency, July Fluvial Design Guide. Environment Agency, June Tamar Catchment Flood Management Plan, Summary Report. JBA Consulting, January Plymouth City Council, Plymouth Level 2 Strategic Flood Risk Assessment, Final Report. Ordnance Survey Explorer (2012) 1:50,000 Map 201: Plymouth and Launceston. Ordnance Survey 1:10,000 Scale Electronic Data Mapping for assessment area. Pell Frischmann, July Plymouth City Council, Strategic Flood Risk Assessment, R02701R001, Final Draft. UK Climate Projections science report: Climate change projections, Version 3, updated December JER6216 rpsgroup.com/uk

26 Drawings JER6216 rpsgroup.com/uk

27 Appendices JER6216 rpsgroup.com/uk

28 Appendix 1 RPS Flood Risk Assessment May 2014 JER6216 rpsgroup.com/uk

29 Appendix 2 Correspondence Environment Agency and Plymouth City Council JER6216 rpsgroup.com/uk

30 Appendix 3 Topographic Survey JER6216 rpsgroup.com/uk

31 Appendix 4 Drainage plans JER6216 rpsgroup.com/uk

32 Appendix 5 WinDes calculations JER6216 rpsgroup.com/uk

33 Pre Development runoff rate Region QBAR (l/s) Q (2yrs) (l/s) Q (1 yrs) (l/s) Q (30 yrs) (l/s) Q (100 yrs) (l/s) Region Region Region Region Region Region 6/Region Region Region Region Ireland National Ireland East Ireland South Ireland West Ireland Greater Dublin Post Development runoff rate Region QBAR (l/s) Q (2yrs) (l/s) Q (1 yrs) (l/s) Q (30 yrs) (l/s) Q (100 yrs) (l/s) Region Region Region Region Region Region 6/Region Region Region Region Ireland National Ireland East Ireland South Ireland West Ireland Greater Dublin JER6216 rpsgroup.com/uk

34 JER6216 rpsgroup.com/uk