Severn Tidal Tributaries Catchment Flood Management Plan Summary Report December 2009 Managing Flood Risk We Are the Environment Agency
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Severn Tidal Tributaries 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 Sapphire East 550 Streetsbrook Road, Solihull, B91 1QT 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 Severn Tidal Tributaries Catchment Flood Management Plan (CFMP). This CFMP gives an overview of the flood risk in the Severn Tidal Tributaries catchment and sets out our preferred plan for sustainable flood risk management over the next 50 to 100 years. The Severn Tidal Tributaries CFMP is one of 77 CFMP’s 2,562 properties and 6,000 people at risk in the for England and Wales. Through the CFMP’s, we have catchment in a 1% flood event. However, it is expected assessed inland flood risk across all of England and that both of these figures could rise quite significantly Wales for the first time. The CFMP considers all types within the next 100 years by which point some 3,720 of inland flooding, from rivers, ground water, surface properties and 7,000 people could be affected by water and tidal flooding, but not flooding directly flooding in a 1% event. This is an increase of 29% from the sea (coastal flooding), which is covered by and 17% respectively. Shoreline Management Plans (SMPs). Our coverage We cannot reduce flood risk on our own, we will of surface and ground water is however limited due therefore work closely with all our partners to improve to a lack of available information. the co-ordination of flood risk activities and agree the The role of CFMP’s is to establish flood risk management most effective way to manage flood risk in the future. policies which will deliver sustainable flood risk Amongst others, Local Authorities, Natural England, management for the long term. This is essential if we the Forestry Commission, National Farmers Union (NFU) are to make the right investment decisions for the future and the Lower Severn Internal Drainage Board have and to help prepare ourselves effectively for the impact been involved in the formulation of this plan. of climate change. We will use CFMP’s to help us target This is a summary of the main CFMP document, if you our limited resources where the risks are greatest. need to see the full document an electronic version This CFMP identifies flood risk management policies to can be obtained by emailing enquiries@environment- assist all key decision makers in the catchment. It was agency.gov.uk alternatively paper copies can be viewed produced through a wide consultation and appraisal at any of our offices in Midlands Region. 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 other’s progress, discuss what has been achieved and consider where we may need to review parts of the CFMP. The Severn Tidal Tributaries catchment area has a long history of river, tidal and surface water flooding. Mark Sitton-Kent At present it is estimated that there are approximately Midlands Regional Director Environment Agency Severn Tidal Tributaries 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 Forest of Dean and Cinderford Streams 12 2 Severn Vale 14 3 Gloucester Streams 16 4 Cotswolds 18 5 Frome 20 6 Little Avon, Cam and Thornbury 22 7 Avonmouth and Severnside 24 8 Lydney 26 Map of CFMP policies 28 2 Environment Agency Severn Tidal Tributaries Catchment Flood Management Plan The purpose of a CFMP in managing flood risk CFMPs help us to understand the • IDBs, water companies and CFMPs aim to promote more scale and extent of flooding now other utilities to help plan their sustainable approaches to managing and in the future, and set policies activities in the wider context flood risk. The policies identified in for managing flood risk within the of the catchment; the CFMP will be delivered through a catchment. CFMPs should be used combination of different approaches. • Transportation planners; to inform planning and decision Together with our partners, we making by key stakeholders such as: • Land owners, farmers and will implement these approaches land managers that manage through a range of delivery plans, • the Environment Agency, who will and operate land for projects and actions. use the plan to guide decisions agriculture, conservation on investment in further plans, The relationship between the CFMP, and amenity purposes; projects or actions; delivery plans, strategies, projects • the public and businesses to and actions is shown in figure 1. • Regional Planning bodies and enhance their understanding local authorities who can use of flood risk and how it will the plan to inform spatial be managed. planning activities and emergency 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 • Make sure our spending delivers the best and restore floodplains. possible outcomes. • Prepare for and manage floods • Focus on risk based targets, for example (including local Flood Warning plans). numbers 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 • Surface water management plans. identify the need and encourage their development. Environment Agency Severn Tidal Tributaries Catchment Flood Management Plan 3 Catchment overview The Severn Tidal Tributaries CFMP the River Severn from its source at A large proportion of the people is located in the south west of Plynlimon in the Welsh mountains that live in the CFMP area live England, it covers an area of to the boundary with the Severn and work in smaller towns and over 1,000km2 and is made Tidal Tributaries CFMP at Gloucester. villages outside the main urban up of six sub-catchments each areas. Tourism, agriculture and The study area is largely rural, draining into the tidal River Severn small businesses are central to although there are several large downstream of Gloucester. These the financial wellbeing of these urban areas, for example Gloucester sub-catchments are: Avonmouth, communities. Around 90% of in the north of the catchment and the Little Avon and River Cam, the the land use in the catchment is Avonmouth in the south, as well River Frome, the Gloucester streams related to agriculture. The as the urban areas of Thornbury (including the Dimore Brook, Sud agricultural land is mainly Grade 3 and Stroud on the eastern side Brook, River Twyver, Daniels Brook (good to moderate quality) with of the study area and Cinderford and Wotton Brook), Westbury Brook isolated pockets of the highest grade and Lydney on the western side. and Walmore Common and the soils along the Severn Valley. Approximately 8% of the catchment Forest of Dean (including the River is classified as urban and the The topography of the catchment can Lyd and Cinderford Streams). We catchment has a population of be divided into three areas: the wide, have produced a separate CFMP for approximately 313,000. low-lying Severn Valley floodplain, the ridges and valleys of the Forest of Dean and the steep sided valleys of the Cotswolds which develop into an open, gently rolling landscape. The topography dominates river flow characteristics, with fast flowing streams draining from the high ground of the Forest of Dean to the west and the Cotswolds to the east. Drainage within the Severn Valley floodplain is much slower and is managed through a complex network of artificial and modified channels. The Severn Tidal Tributaries CFMP is partially situated within the Cotswolds Area of Outstanding Natural Beauty (AONB). As well as this, the study area is also home to a number of internationally and nationally designated landscape habitats including Special Protection Areas (SPAs), Special Areas of Conservation (SAC), a Ramsar site and Sites of Special Scientific Interest (SSSI). Cinderford Brook 4 Environment Agency Severn Tidal Tributaries Catchment Flood Management Plan Map 1. Location and extent of Severn Tidal Tributaries CFMP Area Environment Agency Severn Tidal Tributaries 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 Severn Tidal Tributaries CFMP At present there are around 6,037 the chance (probability) of a area has a long history of river, people and 3,235 commercial and particular flood and the impact (or tidal and surface water flooding. residential properties at risk in the consequence) that the flood would The most significant event in whole catchment from a 1% annual have if it happened. The probability recent years occurred throughout probability river flood. This means of a flood relates to the likelihood of the catchment in June/July 2007 that 1.9% of the total population a flood of that size occurring within as a result of a period of living in the catchment are currently a one year period, it is expressed exceptional rainfall.