North and Mid Somerset Catchment Flood Management Plan Summary Report June 2012 managing flood risk We are the Environment Agency. It’s our job to look after your environment and make it a better place – for you, and for future generations. Your environment is the air you breathe, the water you drink and the ground you walk on. Working with business, Government and society as a whole, we are making your environment cleaner and healthier. The Environment Agency. Out there, making your environment a better place. Published by: Environment Agency Manley House Kestrel Way Exeter EX2 7LQ Tel: 0870 8506506 Email: [email protected] www.environment-agency.gov.uk © Environment Agency All rights reserved. This document may be reproduced with prior permission of the Environment Agency. June 2012 Introduction I am pleased to introduce our summary of the North and Mid Somerset Catchment Flood Management Plan (CFMP). This CFMP gives an overview of the flood risk in the North and Mid Somerset catchment and sets out our preferred plan for sustainable flood risk management over the next 50 to 100 years. The North and Mid Somerset CFMP is one of 77 CFMPs The North and Mid Somerset catchment has a history of for England and Wales. Through the CFMPs, we have flood risk. Over the last 50 years numerous engineering assessed inland flood risk across all of England and schemes have been implemented to reduce flood risk Wales for the first time. The CFMP considers all types of in the catchment. At present 2,300 properties are at risk inland flooding, from rivers, ground water, surface in the catchment in a 1% event (taking into account water and tidal flooding, but not flooding directly from flood defences). This will increase to over 4,200 the sea (coastal flooding), which is covered by properties in the future. Shoreline Management Plans (SMPs). Our coverage of We cannot reduce flood risk on our own, we will surface and ground water is however limited due to a therefore work closely with all our partners to improve lack of available information. the co-ordination of flood risk activities and agree the The role of CFMPs is to establish flood risk management most effective way to manage flood risk in the future. policies which will deliver sustainable flood risk We have worked with others including: Somerset management for the long term. This is essential if we County Council, Natural England, Wessex Water and the are to make the right investment decisions for the National Farmers Union to develop this plan. future and to help prepare ourselves effectively for the This is a summary of the main CFMP document, if you impact of climate change. We will use CFMPs to help us need to see the full document an electronic version can target our limited resources where the risks are be obtained by emailing greatest. [email protected] This CFMP identifies flood risk management policies to or alternatively paper copies can be viewed at any of assist all key decision makers in the catchment. It was our offices in South West Region. produced through a wide consultation and appraisal process; however it is only the first step towards an integrated approach to Flood Risk Management. As we all work together to achieve our objectives, we must monitor and listen to each others progress, discuss what has been achieved and consider where we may Richard Cresswell need to review parts of the CFMP. South West Regional Director Environment Agency North and Mid Somerset Catchment Flood Management Plan 1 Contents The purpose of a CFMP in managing flood risk 3 Catchment overview 4 Current and future flood risk 6 Future direction for flood risk management 10 Sub-areas 1 Portbury sub-area 12 2 Congresbury and Bruton sub-area 14 3 Weston-super-Mare sub-area 15 4 River Axe and River Brue sub-area 16 5 Coastal Towns sub-area 17 6 North Somerset Moors sub-area 18 7 Levels and Moors Towns sub-area 20 8 Levels and Moors sub-area 22 9 Uplands sub-area 24 Map of CFMP policies 25 2 Environment Agency North and Mid Somerset Catchment Flood Management Plan The purpose of a CFMP in managing flood risk CFMPs help us to understand the • Internal Drainage Boards (IDB), CFMPs aim to promote more scale and extent of flooding now and water companies and other sustainable approaches to in the future, and set policies for utilities to help plan their managing flood risk. The policies managing flood risk within the activities in the wider context of identified in the CFMP will be catchment. CFMPs should be used to the catchment; delivered through a combination of inform planning and decision different approaches. Together with • transportation planners; making by key stakeholders such as: our partners, we will implement • land owners, farmers and land these approaches through a range • the Environment Agency, who will managers that manage and of delivery plans, projects and use the plan to guide decisions operate land for agriculture, actions. on investment in further plans, conservation and amenity projects or actions; The relationship between the CFMP, purposes; delivery plans, strategies, projects • Regional Assemblies and local • the public and businesses to and actions is shown in Figure 1. authorities who can use the plan enhance their understanding of to inform spatial planning flood risk and how it will be activities and emergency managed. planning; Figure 1. The relationship between CFMPs, delivery plans, projects and actions Policy planning • CFMPs and Shoreline Management Plans. • Action plans define requirement for delivery plans, projects and actions. Policy delivery plans (see note) Projects and actions • Influence spatial planning to reduce risk and • Make sure our spending delivers the best restore floodplains. possible outcomes. • Prepare for and manage floods (including local • Focus on risk based targets, for example numbers Flood Warning plans). of households at risk. • Managing assets. • Water level management plans. • Land management and habitat creation. Note: Some plans may not be led by us – we may identify the • Surface water management plans. need and encourage their development. Environment Agency North and Mid Somerset Catchment Flood Management Plan 3 Catchment overview The catchment of the rivers in the located on the coastal plain, include The underlying rock has a significant North and Mid Somerset CFMP are Weston-super-Mare, Burnham-on- influence on the catchment’s located in the south west of England. Sea and Highbridge, Portishead and response to rainfall, with high run-off They drain from the Mendips, flowing Clevedon, Nailsea, Congresbury, from the impermeable uplands in the via various channels through the Cheddar, and Glastonbury and south east and water-logging of the low-lying coastal plain to the Severn Street. clay lowlands. Permeable uplands in Estuary. the north east results in many rivers’ The rivers and streams flow from headwaters being limestone springs. Map 1 shows the location and extent their source in the Mendips in the of the North and Mid Somerset CFMP east of the catchment; they flow in a The catchment contains a number of area. It includes the rivers Brue, Axe, westerly direction through low-lying designated sites of national and Congresbury Yeo, Land Yeo, Banwell coastal plain, before flowing out into international importance. A and Portbury Ditch. The downstream the Severn Estuary through tidal significant part of the low-lying limits of the CFMP area meet with the exclusion sluices. Somerset Moors are designated upstream boundary of the North Special Protection Areas (SPA) and a The rivers Brue and Axe flow through Devon and Somerset Shoreline Ramsar site, which depend upon the Somerset Levels and Moors, Management Plan (SMP) boundary at flooding. The area is also rich in where they are embanked and in tidal sluices on the Brue and Axe, archaeological sites that depend on some places perched above the and with the Severn Estuary SMP at waterlogged conditions for their surrounding floodplain. In the tidal sluices on the rest. preservation. Somerset Levels and Moors, flooding North Devon and Somerset and is caused by long duration storms or Important environmental sites in the Severn Estuary SMPs deal with a series of storms. The high-level catchment include two Areas of coastal flood management, while the embanked channels overflow and Outstanding Natural Beauty, three CFMP considers the flood risk from floodwater is stored in the moors Special Areas of Conservation, two tide-locking. before it can reach the estuary. The Ramsar and two SPA (including the capacity of these channels can be Severn Estuary), 74 Sites of Special The overall catchment area is about significantly reduced by high tidal Scientific Interest, nine National 1,100 square kilometres, and has a conditions. Internal Drainage Boards Nature Reserves and over 300 population of around 275,000. It’s a have an important role in managing Schedule Monuments. rural catchment, with urban areas land drainage within these low-lying making up only five per cent of the moors. total. Its main urban areas, mainly 4 Environment Agency North and Mid Somerset Catchment Flood Management Plan Map 1. Location and extent of the North and Mid-Somerset CFMP area Legend Portishead North and Mid Somerset CFMP Nailsea Clevedon Urban areas Main rivers Weston- Bristol Railway super-Mare Yatton Motorway Bath Brean Cheddar Burnham Wells Shepton N Mallet Bridgwater Glastonbury Street Bruton Somerton Wincanton 0 3 6 9 12 Kilometres © Crown Copyright. Environment Agency 100026380. ➜ Minor works undertaken on the River Brue near Glastonbury Environment Agency North and Mid Somerset Catchment Flood Management Plan 5 Current and future flood risk Overview of the current flood risk What is at risk? Flood risk has two components: the Currently the main sources of flood At present there are around 7,000 chance (probability) of a particular risk for people, property, people and 3,000 commercial and flood and the impact (or infrastructure and the land are: residential properties at risk in the consequence) that the flood would whole catchment from a 1% annual • river flooding from the River Brue, have if it happened.