Strategic Flood Risk Assessment July 2019
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2019s0332 – Strategic Flood Risk Assessment for Hinckley and Bosworth Borough Council Final Report July 2019 www.jbaconsulting.com Hinckley and Bosworth Borough Council i | P a g e 2019s0332 - Hinckley and Bosworth Borough Council - L1 SFRA Update Final v1.0.docx Joanne Chillingworth The Library St Philips Courtyard Church Hill Coleshill Warwickshire B46 3AD Revision history Revision Ref/Date Amendments Issued to Draft Report v1.0 / 9th Chris Colbourn and May 2019 Rob Foers, Hinckley & Bosworth Borough Council Final Report v1.0 / 05th Chris Colbourn and July 2019 Rob Foers, Hinckley & Bosworth Borough Council Contract This report describes work commissioned by Chris Colbourn, on behalf of Hinckley and Bosworth Borough Council, by an email dated 5th March 2019. Joanne Chillingworth, Hannah Coogan, Lucy Finch and Adam Church of JBA Consulting carried out this work. Prepared by ............................... Lucy Finch BSc Analyst ................................................ Adam Church BSc Assistant Analyst Reviewed by .............................. Joanne Chillingworth BSc MSc MCIWEM C.WEM ................................................ Principal Analyst ................................................ Hannah Coogan BSc MCIWEM C.WEM Technical Director Purpose This document has been prepared as a Draft Report for Hinckley and Bosworth Borough Council. 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 Hinckley and Bosworth Borough Council. ii | P a g e 2019s0332 - Hinckley and Bosworth Borough Council - L1 SFRA Update Final v1.0.docx Acknowledgements We would like to acknowledge the assistance of: • Hinckley and Bosworth Borough Council; • Environment Agency; • Severn Trent Water; • Leicestershire Fire and Rescue Service; • The Canal and Rivers Trust; and, • Planners at the neighbouring authorities Copyright © Jeremy Benn Associates Limited 2019. Carbon footprint JBA is aiming to reduce its per capita carbon emissions. iii | P a g e 2019s0332 - Hinckley and Bosworth Borough Council - L1 SFRA Update Final v1.0.docx Executive summary This report provides a comprehensive and robust evidence base on flood risk issues to support the production of the Local Plan to 2036. This is a Level 1 Strategic Flood Risk Assessment (SFRA) and it will be used to inform decisions on the location of future development and the preparation of sustainable policies for the long-term management of flood risk. Introduction This Strategic Flood Risk Assessment (SFRA) document provides an update to the Joint 2014 SFRA for Hinckley and Bosworth, Blaby and Oadby and Wigston Borough Councils, as well as an update to the Leicestershire and Leicester City 2017 SFRA. Both of these existing SFRAs contained relevant data to Hinckley and Bosworth but included a much larger area and additional Local Authorities. This study provides a comprehensive and robust evidence base to support the new Hinckley and Bosworth Borough Council Local Plan. The key objectives are: • To update the Council's Joint 2014 SFRA and the 2017 SFRA, taking into account the most recent policy and legislation in the National Planning Policy Framework (2019). • To collate and analyse the latest available information and data for current and future (i.e. climate change) flood risk from all sources, and how these may be mitigated. • To inform decisions in the emerging Local Plan, including the selection of development sites and planning policies. • To provide evidence to support the application of the Sequential Test for the allocation of new development sites, to support the Council’s preparation of the Local Plan. • To provide a comprehensive set of maps presenting flood risk from all sources that can be used as evidence base for use in the emerging Local Plan. • To provide advice for applicants carrying out site-specific flood risk assessments and outline specific measures or objectives that are required to manage flood risk. Summary of flood risk in Hinckley and Bosworth Borough • Past flooding information available for this study is limited. The data that does exist shows that the main risk is from surface water and culverted watercourses. The most affected areas for historic flooding correspond with the main urban areas in the borough, including Hinckley, Barwell, Earl Shilton, Desford, Ratby and Groby, although there are some records of historical flooding in rural areas. • The main rivers associated with fluvial flooding are the River Anker and River Sence, which pose a flood risk to settlements including Sheepy Magna, Shackerstone, Witherley and the outskirts of Atherstone. Additionally, there is fluvial flood risk posed to the borough by a number of smaller watercourses. Within Hinckley and Burbage, the Battle Brook, Harrow Brook and Sketchley brook pose a fluvial flooding risk. In the east of the borough, the Rothley Brook poses a fluvial flood risk to the urban areas of Groby and Ratby. iv | P a g e 2019s0332 - Hinckley and Bosworth Borough Council - L1 SFRA Update Final v1.0.docx • The Areas Susceptible to Groundwater Flooding map shows that, in general, the majority of Hinckley and Bosworth borough is within the <25% susceptible classification, therefore it is at lower risk of groundwater flooding. Parts of the borough around Stoke Golding, Newbold Verdon and Desford, and the west of the borough along the River Sence channel fall within higher susceptibility classifications and are therefore at higher risk from groundwater flooding. • There is one canal located within Hinckley and Bosworth borough, the Ashby Canal. These have the potential to interact with other watercourses and become flow paths during flood events or in a breach scenario. There have been five recorded incidents of canal breach from 1981 to 1990, and three recorded incidents of canal overtopping from 2012 to 2016. The canal breach incidents occurred in primarily rural locations on the stretch of the canal between Congerstone and Shenton. The canal overtopping incidents occurred in Stoke Golding and Hinckley. • There is a potential risk of flooding from reservoirs both within the borough and those outside. There are four reservoirs within Hinckley and Bosworth borough. There are no records of flooding from reservoirs in the study area. The level and standard of inspection and maintenance required under the Reservoirs Act means that the risk of flooding from reservoirs is relatively low. However, there is a residual risk of a reservoir breach and this risk should be considered in any site-specific Flood Risk Assessments (where relevant). How to use this report Planners The SFRA provides recommendations regarding all sources of flood risk in Hinckley and Bosworth borough, which can be used to inform policy on flood risk within the Local Plan. This includes how the cumulative impact of development should be considered. It provides the latest flood risk data and guidance to inform the Sequential Test and provides guidance on how to apply the Exception Test. The Borough Council will use this information to apply the Sequential Test to strategic allocations and identify where the Exception Test will also be needed. The SFRA provides guidance for developers, which can be used by Development Management staff to assess whether site specific Flood Risk Assessments meet the required quality standard. Developers For sites that are not strategic allocations, developers will need to use this SFRA to help apply the Sequential Test. For all sites, whether strategic allocations or windfall sites, developers will need to apply the Exception Test and use information in a site-specific Flood Risk Assessment to inform this test at planning application stage. When assessing sites not identified in the Local Plan (windfall sites), developers should use evidence provided in this SFRA to apply the Sequential Test as well as providing evidence to show that they have adequately considered other reasonably available sites. v | P a g e 2019s0332 - Hinckley and Bosworth Borough Council - L1 SFRA Update Final v1.0.docx This SFRA provides guidance for the application of the Sequential and Exception Tests at a site level and for detailed site-specific Flood Risk Assessments. This is a strategic assessment and does not replace the need for site-specific Flood Risk Assessments where a development is either within Flood Zones 2 or 3 or greater than a hectare in Flood Zone 1. In addition, a surface water drainage strategy will be needed for all major developments in any Flood Zone to satisfy Leicestershire County Council (the Lead Local Flood Authority (LLFA) for the area). Developers can use the information in this SFRA, alongside site specific research to help to scope out what additional work will be needed in a detailed Flood Risk Assessment. To do this they should refer to the Chapter 5 Sources of flooding in Hinckley and Bosworth and the flood maps in the appendices. At the planning application stage, developers may need to undertake more detailed hydrological and hydraulic assessments of the watercourses to verify flood extent (including latest climate change allowances, due to be updated by the Environment Agency in 2019), inform master planning and prove, if required, whether the Exception Test can be passed. As part of the Environment Agency’s updated guidance on climate change, which must be considered for all new developments