Middlesbrough Council Strategic Surface Water Flooding Study

Final Report March 2010 Martin Coleclough Middlesbrough Council PO Box 99 Town Hall Middlesbrough TS1 2QQ

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JBA Office JBA Consulting The Brew House Wilderspool Park Greenall's Avenue Warrington WA4 6HL

JBA Project Manager Sam Wingfield

Revision History Revision Ref / Date Issued Amendments Issued to

Draft version 1.0. January 2010

Martin Coleclough and Cameron Sked

Final version 2.0. March 2010 Updated after Environment Agency and Middlesbrough council comments

Martin Coleclough and Cameron Sked

Contract This report describes work commissioned by Martin Coleclough, on behalf of Middlesbrough Council, by an email dated 17/11/09. Middlesbrough Councils representative for the contract was Martin Coleclough. Sam Wingfield of JBA Consulting carried out this work.

Prepared by .................................................. Sam Wingfield BSc MRes

....................................................................... Analyst

Reviewed by ................................................. Chris Isherwood BSc MSc DipWEM

Analyst

Purpose This document has been prepared as a Final Report for Middlesbrough 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 Middlesbrough Council.

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Acknowledgments JBA would like to thank Martin Coleclough and Steve Binks from Middlesbrough Council who assisted in the production of this report.

Copyright Jeremy Benn Associates Limited 2010

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Executive Summary This strategic surface water study has been completed as a partial update to the Middlesbrough Council Strategic Flood Risk Assessment (2007). A number of government guidance and policy documents, including the Pitt Review, PPS25 and the Flood Risk Regulations (2009) have highlighted the growing responsibilities of local authorities in understanding and managing flooding from other sources within their area. This includes surface water flooding.

Middlesbrough has been subject to extensive flooding in recent years. In November 2000, Middlesbrough suffered record levels of sustained rainfall. This resulted in widespread flooding as watercourses and surface and foul sewer systems became overwhelmed.

In June, July and August 2002, 40 locations in Middlesbrough were subject to flooding. Short periods of high intensity rainfall led to the surface water drainage systems becoming overwhelmed and backing up. This included foul sewer flooding in some properties.

The identification of Critical Drainage Areas (CDAs) has recently become a good staring point in the understanding of risk from surface water flooding within SFRAs. This would usually form part of the scope of a Level 1 SFRA update. However, on review of the current Middlesbrough SFRA (2007), a full review was not prioritised due the lack of significant new flood risk information or proposed development sites. Therefore this study has been prepared to identify candidate CDAs (cCDAs) to help fill the gaps in the flood risk information on surface water flooding which the current SFRA lacks.

Surface water flooding has been highlighted nationally as being a significant issue in Middlesbrough and as a result, Middlesbrough has been allocated Defra funding to complete a Surface Water Management Plan (SWMP). The next stage of this study would be to confirm the cCDAs proposed through consultation between the Environment Agency, Middlesbrough Council and Northumbrian Water but as a SWMP is already being commissioned this will not be required. Instead, the outputs from this study will be used in the early stages and scoping of the SWMP.

The National Surface Water Flood Maps, historic flooding locations (collected from a number of different data holders) and a number of relevant studies were used to describe surface water flood risk in Middlesbrough. This assessment was discussed with Middlesbrough Council's drainage contact. Following this, more detailed surface water mapping was completed for Middlesbrough, using the JBA programme JRAIN. Due to the dense urban environment, this has provided more detailed surface water flow pathways and extents. These maps can be found in Figures C1 to C4 in Appendix A. This more detailed mapping was used, along with comments from Middlesbrough Council to produce cCDAs.

Recommendations for further studies and some SUDS guidance completed this study.

Along with an investigation into surface water flooding, a new set of fluvial and tidal Flood Zone maps have been produced as part of this commission. This was completed to take into account hydraulic model updates post 2007 and to produce new Flood Zone 3b extents (Figures A1 to A4 in Appendix A). Maps showing the National Surface Water Flood Extents and historic flooding locations have also been produced (Figures B1 to B4 in Appendix A).

Contents

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Executive Summary .......................................................................................................... iv

1. Introduction .......................................................................................................... 1

1.1 Purpose of this study ............................................................................................. 11.2 Methodology .......................................................................................................... 21.3 Defra SWMP funding ............................................................................................. 2

2. Background .......................................................................................................... 3

2.1 Flooding ................................................................................................................. 3

3. Data Sources ........................................................................................................ 5

3.1 Areas Susceptible to Surface Water Flooding Map ............................................... 53.2 Detailed surface water modelling .......................................................................... 63.3 Historic surface water flooding locations ............................................................... 63.4 Flooding studies ..................................................................................................... 7

4. Updated Flood Zone Maps .................................................................................. 9

4.1 PPS25 Flood Zone Maps....................................................................................... 94.2 Functional Floodplain ............................................................................................. 9

5. Surface water flood risk in Middlesbrough ....................................................... 11

5.1 Introduction ............................................................................................................ 115.2 Surface water flooding locations in Middlesbrough ............................................... 135.3 Candidate Critical Drainage Areas ........................................................................ 255.4 Improvement schemes .......................................................................................... 29

6. Next Stages and Recommendations ................................................................. 31

6.1 Future studies ........................................................................................................ 316.2 Surface water drainage and development ............................................................. 31

Appendices........................................................................................................................ I

A. Figures .................................................................................................................. I

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List of Figures Figure 2-1 - Sources, pathways and receptors for flooding from other sources ..... 3

Figure 5-1 - Middlesbrough Council topography and watercourses ........................ 11

Figure 5-2 - Valley Road and Marton West Beck ......................................................... 15

Figure 5-3 - Linthorpe and Acklam Green surface water flood risk .......................... 17

Figure 5-4 - Gresham Road surface water flood risk .................................................. 18

Figure 5-5 - Coulby Newham surface water flood risk ................................................ 19

Figure 5-6 - North Ormesby Area .................................................................................. 21

Figure 5-7 - Ormesby Beck ............................................................................................ 22

Figure 5-8 - Surface water flow pathway at Park End and Prissick ........................... 23

Figure 5-9 - Surface water issues at Nunthorpe ..............................