Leicestershire and Leicester City Level 1 Strategic Flood Risk Assessment Final Report October 2017 This page has intentionally been left blank 2017s5956 Level 1 SFRA Final v1.0.docx i JBA Project Manager Claire Gardner The Library St Philips Courtyard Church Hill COLESHILL Warwickshire B46 3AD Revision History Revision Ref / Date Issued Amendments Issued to Rev 1.0 / June 2017 DRAFT for comment Commissioning authorities Rev 2.0 / June 2017 Minor typo corrections, Commissioning authorities updated with climate change Environment Agency information and flood risk management information Rev 1.0 / September 2017 FINAL DRAFT for comment Commissioning authorities Environment Agency Rev 1.0 / October 2017 FINAL Commissioning authorities Contract This report describes work commissioned by the non-unitary authorities of Leicestershire, Leicester City Council and Leicestershire County Council. The Council’s joint representative for the contract was David Nash, Strategic Planning Consultant supporting the Joint Strategic Planning Manager for the County and Districts of Leicestershire, Leicester City and the LLEP. Prepared by .................................................. Sophie Dusting BSc MEPS Analyst Freyja Scarborough BSc MSc Assistant Analyst Reviewed by ................................................. Claire Gardner BSc MSc MCIWEM C.WEM Chartered Senior Analyst Purpose This document has been prepared as a Final Report for the client. JBA Consulting accepts no responsibility or liability for any use that is made of this document other than by the Client for the purposes for which it was originally commissioned and prepared. JBA Consulting has no liability regarding the use of this report except to the client. 2017s5956 Level 1 SFRA Final v1.0.docx ii Acknowledgements We would like to acknowledge the assistance of: All the commissioning authorities; The Lead Local Flood Authorities (Leicester City Council and Leicestershire County Council); Environment Agency; Canal and River Trust; Highways England; Fire and Rescue Service; Trent Rivers Trust; Welland Rivers Trust; and, Planners at the neighbouring authorities Copyright © Jeremy Benn Associates Limited 2017 Carbon Footprint A printed copy of the main text in this document will result in a carbon footprint of 619g if 100% post- consumer recycled paper is used and 787g if primary-source paper is used. These figures assume the report is printed in black and white on A4 paper and in duplex. JBA is aiming to reduce its per capita carbon emissions. 2017s5956 Level 1 SFRA Final v1.0.docx iii Executive Summary Introduction The main purpose of this Strategic Flood Risk Assessment (SFRA) is to provide a comprehensive and robust evidence base to support the production of the Strategic Growth Plan (SGP), being prepared by the seven non-unitary borough and district councils in Leicestershire, Leicestershire County Council and Leicester City Council. SFRA objectives The key objectives of the 2017 Strategic Flood Risk Assessment are: To provide up to date information and guidance on flood risk across Leicestershire County and Leicester City, taking into account the latest flood risk information and the current state of national planning policy; To determine the variations in current and future flood risk from all sources of flooding in Leicestershire County and Leicester City; To identify the requirements for site-specific flood risk assessments; To consider opportunities to reduce flood risk to existing communities and developments; To enable the commissioning authorities to apply the Sequential Test and aid authorities in identifying when the Exception Test is required, when determining preferred directions of growth; and, To inform the Sustainability Appraisal of the SGP, so that flood risk is taken into account when considering strategic growth options. SFRA outputs This report fulfils a Level One SFRA requirement. Assessment of all potential sources of flooding; Mapping of location and extent of functional floodplain; Mapping of areas covered by an existing flood alert and flood warning; Mapping of areas protected by existing flood defences and their condition; Assessment of standard of protection provided by existing flood risk management infrastructure; Assessment of the potential impact of climate change on flood risk; Assessment of locations where additional development may increase flood risk elsewhere; Details of where proposed flood schemes are planned; Recommendations of the criteria that should be used to assess future development proposals and the development of a Sequential Test and sequential approach to flood risk; and, Guidance for developers including requirements for site-specific flood risk assessments and the application of sustainable drainage systems. Summary of the SFRA Appraisal of flood risk There have been several recorded flood incidents across Leicestershire County and Leicester City, from a combination of sources. Prominent sources of flooding are fluvial, surface water, sewer and flood incidents associated with water infrastructure issues such as culvert blockages or insufficient capacity in the sewer network. Much of the fluvial flood risk in the study area is associated with the River Soar and its tributaries, as well as the River Welland, the River Avon and the River Sence. There are also numerous ordinary watercourses that pose a flood risk in the area. Often the combination of watercourses and the interaction of two or more sources of out of bank flow across the floodplain can have profound implications for the extent of the risk. Surface water is one of the primary flood risks in the study area. Several urban areas and rural settlements have a well-documented history of surface water flooding and the Risk of Flooding from Surface Water (RoFfSW) mapping shows several prominent overland flow 2017s5956 Level 1 SFRA Final v1.0.docx iv routes, following topographical flow paths of existing watercourses or dry valleys and local road infrastructure with some isolated ponding located in low-lying areas. The sewers are managed by two Water and Sewerage Companies; Anglian Water and Severn Trent Water. Previous SFRAs note much of the sewer network dates to the Victorian era and the capacity and conditions of sections of the network is unknown. Several historic records relate to sewer flooding. However, for areas where there were re- occurring issues maintenance work may have been undertaken and the risk may have been removed or reduced. There are very few recorded incidents of groundwater flooding in the study area. A desk- study review of existing assessments and documents has identified six potential groundwater flooding mechanisms in Leicester City and Leicestershire County. There are no records of flooding from reservoirs impacting properties inside the study area. There are three canals in the study area: Grantham Canal, Grand Union Canal and Ashby Canal. 26 records of a canal overtopping have been recorded across the study area from 1969 to 2013. Currently there are 16 Flood Alert Areas and 59 Flood Warning Areas (FWAs) covering the study area. Flood defences A high-level review of existing flood defences was undertaken and found several communities benefit from flood defences and alleviation schemes in Leicestershire County and Leicester City. The Environment Agency’s Raised Flood Defences dataset indicates that there are notable differences between the design and current standard of protection and there are locations where defences are considered to be in a poor condition. There are also several assets which are considered to significantly affect whether areas will flood in Leicester and there are also other flood risk management initiatives such as property level flood protection schemes and retro-fits SuDS schemes. There are several on-going schemes and projects to reduce the risk of flooding in Leicestershire comprising natural flood management initiatives. Where areas benefit from defences and alleviation measures, there remains a residual risk, should the defences breach or fail. At the time of preparing this SFRA, the areas benefiting from defences dataset was in the process of being updated. Relevant studies There are many relevant regional and local key studies which complement the SFRA and have been considered, such as the Catchment Flood Management Plan, River Basin Management Plan, Preliminary Flood Risk Assessments and Local Flood Risk Management Strategies. Other policy considerations have also been incorporated, such as sustainable development principles, climate change and flood risk management Policy Recommendations The following policy recommendations are to be considered by the commissioning authorities in the development of the Strategic Growth Plan. Development and planning considerations Identifying potential growth areas and future development The sequential approach to development and flood risk should be adopted, directing new development to areas of lowest risk. It is recommended that the climate change modelling and mapping in this SFRA is taken into consideration when identifying sites for development in the proposed growth areas. The potential growth area summary tables provide an indication on where flood risk may need to be investigated in more detail as part of a site-specific Flood Risk Assessment. This may include areas where: o The Environment Agency’s Flood Zone maps do not cover the watercourse. Environment Agency mapping of Flood Zones covers watercourses with a catchment