Tamar 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 Tamar Catchment Flood Management Plan (CFMP). This CFMP gives an overview of the flood risk in the Tamar catchment and sets out our preferred plan for sustainable flood risk management over the next 50 to 100 years. The Tamar CFMP is one of 77 CFMPs for England and Flooding within the Tamar catchment can be attributed Wales. Through the CFMPs, we have assessed inland to flooding from the rivers, estuaries, surface water run- flood risk across all of England and Wales for the first off and drainage systems. Previous incidents include time. The CFMP considers all types of inland flooding, flooding in Launceston in December 1979, widespread from rivers, ground water, surface water and tidal flooding in October 2000 and a dramatic event in flooding, but not flooding directly from the sea (coastal Canworthy Water in August 2004. While the numbers of flooding), which is covered by Shoreline Management properties at risk across the Tamar catchment may be Plans (SMPs). Our coverage of surface and ground relatively low compared with other areas of the country, water is however limited due to a lack of available the risk to life, and community disruption caused by information. flooding, can be just as significant. The role of CFMPs is to establish flood risk management We cannot reduce flood risk on our own, we will policies which will deliver sustainable flood risk therefore work closely with all our partners to improve management for the long term. This is essential if we the co-ordination of flood risk activities and agree the are to make the right investment decisions for the most effective way to manage flood risk in the future. future and to help prepare ourselves effectively for the We have worked with others including Plymouth City impact of climate change. We will use CFMPs to help us Council, Natural England, South West Water and the target our limited resources where the risks are National Farmers Union to develop this plan. greatest. This is a summary of the main CFMP document, if you This CFMP identifies flood risk management policies to need to see the full document an electronic version can assist all key decision makers in the catchment. It was be obtained by emailing produced through a wide consultation and appraisal [email protected] process, however it is only the first step towards an or alternatively paper copies can be viewed at any of integrated approach to Flood Risk Management. As we our offices in South West Region. 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 Tamar 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 Tamar sub-area 12 2 Tidal Central sub-area 13 3 Plymouth sub-area 14 4 East Tamar sub-area 16 5 Central Tamar sub-area 18 6 West Tamar sub-area 20 Map of CFMP policies 21 2 Environment Agency Tamar 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 Tamar Catchment Flood Management Plan 3 Catchment overview The Tamar catchment lies between lowlands. The England and Wales Most of the catchment is rural, with the East Cornwall, North Devon and average is 920mm (36in). only four per cent being urbanised. South Devon CFMP areas. It drains However the principal urban centre is Granites make the upper catchment an area of 1,800 square kilometres Plymouth, which is the most relatively impervious which in turn (700 square miles). The River Tamar populous city in Devon and Cornwall. leads to the flashy nature of rivers meets the sea at Plymouth Sound, Tavistock and Launceston are the and their tributaries, often resulting with the Tamar estuary extending other major settlements within the in water levels rising rapidly in a approximately 22km inland to catchment, along with Saltash, short time. The lower areas have Gunnislake. Plympton and Plymstock (which are sandstones and mudstones overlain all within the housing market area of The topography of the Tamar with alluvial silts and clays and Plymouth). Just over 341,000 people catchment is varied. The main terrace deposits from rivers and sea. live in the Tamar catchment. Over upland areas are west Dartmoor and The Tamar catchment is 250,000 of these are in the Plymouth east Bodmin moor, from which the environmentally rich with many area. Thrushel, Lyd, Tavy, Walkham, Plym, important environmental locations, Yealm, Ottery, Kensey and Inny rivers and some quality river systems. The spring. The remainder of the area has a rich mining heritage with catchment is made up of rolling the western edge of the catchment farmland, valleys and heaths. The included in the Cornish mining World River Tamar itself originates from the Heritage site. There are three Areas far northern part of the catchment, in of Outstanding Natural Beauty, five the hills close to the North Devon Special Areas of Conservation (SAC), coast. Annual rainfall ranges from one Special Protection Area (SPA), 61 more than 2,000mm (80in) on the Sites of Special Scientific Interest edge of Dartmoor to less than (SSSIs) and 880 Scheduled 1,000mm (40in) on the coastal Monuments. Granites make the upper catchment relatively impervious which in turn leads to the flashy nature of rivers and their tributaries, often resulting in water levels rising rapidly in a short time. 4 Environment Agency Tamar Catchment Flood Management Plan Map 1. Location and extent of the Tamar CFMP area Legend Great Torrington Tamar CFMP Urban areas Bude Main rivers Railway Okehampton Motorway Camelford Launceston Tavistock N Callington Horrabridge Bodmin Liskeard Plymouth Ivybridge 0 4 8 12 16 Kilometres © Crown Copyright. Environment Agency 100026380. ➜ Flooding from the River Kensey at Newport in Launceston in 1980 Environment Agency Tamar Catchment Flood Management Plan 5 Current and future flood risk Overview of the current flood risk What is at risk? There is a recorded history of 1974, very high tides in the Tamar Today, this accounts for over 2,750 flooding within the Tamar catchment estuary caused areas of Calstock, properties across the catchment at that dates back to the 19th Century. Cargreen, Morwellham, and potential risk of flooding from rivers This is from a range of sources: Millbrook to flood. and the tide (excluding those behind rivers, the estuaries, surface water defences). While the numbers of properties at run-off and sewer systems. risk across the Tamar catchment may Also at risk are the police station at More recent flooding incidents be relatively low compared with Tavistock, the A30 and A374, the include Launceston in December other areas of the country, the risk to mainline railway in at least three 1979, widespread flooding in life, and community disruption locations, two schools, a nursery and October 2000 and extreme flooding caused by flooding can be just as a health centre.