Parrett Catchment Flood Management Plan Summary Report December 2009 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. December 2009 Introduction I am pleased to introduce our summary of the Parrett Catchment Flood Management Plan (CFMP). This CFMP gives an overview of the flood risk in the Parrett catchment and sets out our preferred plan for sustainable flood risk management over the next 50 to 100 years. The Parrett CFMP is one of 77 CFMPs for England and The Parrett catchment has a history of flood risk. Over Wales. Through the CFMPs, we have assessed inland the last 70 years numerous engineering schemes have flood risk across all of England and Wales for the first been implemented to reduce flood risk in the time. The CFMP considers all types of inland flooding, catchment. At present 3,300 properties are at risk in the from rivers, ground water, surface water and tidal catchment in a 1% annual probability flood event. This flooding, but not flooding directly from the sea (coastal takes account of flood defences already in place. This is flooding), which is covered by Shoreline Management expected to increase to over 6,600 properties in the Plans (SMPs). Our coverage of surface and ground future. water is however limited due to a lack of available We cannot reduce flood risk on our own, we will information. therefore work closely with all our partners to improve The role of CFMPs is to establish flood risk management the co-ordination of flood risk activities and agree the policies which will deliver sustainable flood risk most effective way to manage flood risk in the future. management for the long term. This is essential if we We have worked with others including: South are to make the right investment decisions for the Somerset, Taunton Deane and Sedgemoor District future and to help prepare ourselves effectively for the Councils, Natural England, Wessex Water and the impact of climate change. We will use CFMPs to help us National Farmers Union to develop this plan. target our limited resources where the risks are This is a summary of the main CFMP document, if you greatest. need to see the full document an electronic version can This CFMP identifies flood risk management policies to be obtained by emailing assist all key decision makers in the catchment. It was [email protected] or alternatively produced through a wide consultation and appraisal paper copies can be viewed at any of our offices in process, however it is only the first step towards an South West Region. 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 need to review parts of the CFMP. Richard Cresswell South West Regional Director Environment Agency Parrett 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 Upper Yeo and Cary sub-area 12 2 Yeovil sub-area 13 3 Upper and NW Parrett and Upper Isle sub-area 14 4 Upper Tone sub-area 15 5 Taunton sub-area 16 6 Somerset Levels and Moors sub-area 18 7 Bridgwater sub-area 20 8 Shoreline sub-area 22 Map of CFMP policies 23 2 Environment Agency Parrett 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 Parrett Catchment Flood Management Plan 3 Catchment overview The catchment of the River Parrett is catchment. They flow in a north and from the impermeable uplands in the located in the south west of England. westerly direction down into an east and waterlogging of the It drains from the Quantocks, extensive lowland floodplain, before lowlands. The area does not have Blackdown Hills and Mendips, flowing out into the Bristol Channel any major aquifers so groundwater flowing through the low-lying through the Parrett Estuary. The flooding is not a major risk. Somerset Levels and Moors to the major rivers start in the steep The catchment contains a number of Bristol Channel at Bridgwater Bay. uplands, then flow through flat lower designated sites of national and moors, where they are embanked Map 1 shows the location and extent international importance. A and in some places perched above of the River Parrett CFMP area. It significant part of the low-lying the surrounding floodplain. The includes the tributaries of the rivers Somerset Moors are designated lower reaches of the rivers Tone and Isle, Tone, Yeo and Cary. Below Special Protection Areas and a Parrett are tidal for some 30km Bridgwater, the downstream limit of Ramsar site, which depend upon (18.6miles) from the Severn Estuary. the CFMP area overlaps with the flooding. The area is also rich in The steepness of the uplands, upstream boundary of the North archaeological sites that depend on coupled with the geology and soil Devon and Somerset Shoreline waterlogged conditions for their conditions, generates quick run-off Management Plan (SMP) boundary. preservation. from short intense rainfall. In the The North Devon and Somerset SMP Somerset Levels and Moors, flooding Important environmental sites in the deals with coastal flood is caused by longer duration storms catchment include 104 square management, while the CFMP or a series of storms of low intensity. kilometres of Areas of Outstanding considers tidal flood risk along the The high-level embanked channels Natural Beauty, 0.8 square Rivers Parrett and Tone to the tidal overflow and floodwater is stored in kilometres of Special Areas of limits at Oath and Newbridge the moors before it can reach the Conservation (SAC), 43 square respectively. estuary. The capacity of these kilometres of Ramsar, 72 square channels can be significantly kilometres of Sites of Special The overall catchment area is about reduced by high tidal conditions Scientific Interest and 112 1,700 square kilometres, and has a backing up the Parrett. Scheduled Monuments. population of around 300,000. It’s a rural catchment, with urban areas Internal Drainage Boards have an making up only four per cent of the important role in managing land total. Its main urban areas include drainage within these low-lying Taunton, Bridgwater and Yeovil. moors. The rivers and streams flow from The underlying rock has a significant their source in the hills in the influence on the catchment’s southwest and east of the response to rainfall, with high run-off 4 Environment Agency Parrett Catchment Flood Management Plan Map 1. Location and extent of the Parrett CFMP area Legend Burnham Parrett CFMP Wells Urban areas Williton Main rivers Railway Bridgwater Motorway Street Castle Langport Cary Taunton Wellington Ilminster Yeovil N Crewkerne Sherborne Chard Honiton Beaminster 0 4 8 12 16 Kilometres © Crown Copyright. Environment Agency 100026380. ➜ Strengthening the historic Baltmoor Wall on the River Tone, one of many flood defences we manage in the catchment Environment Agency Parrett 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 The most recent significant flood in At present there are around 17,000 chance (probability) of a particular the Parrett catchment was the people and 4,000 commercial and flood and the impact (or autumn/winter flooding of 2000, the residential properties at risk in the consequence) that the flood would worst since October 1960.