Environment Agency South West Region INFORMATION SERVICE SOUTH WEST REGION Manley House. Kestrel Way. Exeter EX2 7LQ E n v i r o n m e n t A g e n c y Richard Horrocks Regional Flood Defence Manager Environment Agency South West Region Manley House Kestrel Way Exeter EX2 7LQ Tel 01392 444000 Fax 01392 444238 ISBN 185705 573 x ©Environment Agency All rights reserved. No part of this document may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the Environment Agency. Cover: River Taw at Umberleigh HO-4/01-150-A Printed on recycled paper October/November 2000 Flood Event Report EA South West CONTENTS EXECUTIVE SUMMARY....................................................................................... ...1 1.0 INTRODUCTION 1.1 Event Management............................................................... ................................... 2 1.2 Flood Forecasting..................................................................................................... 2 1.3 Flood Warning.......................................................................................................... 2 1.4 Event Impact............................................................................................................. 2 1.5 Emergency Response................................................................................................ 3 1.6 Public Relations....................................................... .................................................4 2.0 EVENT MANAGEMENT 2.1 Procedures................................................................................................................. 5 2.2 Liaison (Internal/External)........................................................................................ 5 2.3 Communications....................................................................................................... 6 2.4 Numbers of Staff Deployed......................................................................................7 2.5 Range of functions and Inter Regional Co-Operation (event management only). ..7 2.6 Scale (number if possible) of Calls Received...........................................................8 2.7 Issues Arising............................................................................................................ 8 2.8 Recommendations....................................................... ..............................................8 3.0 FLOOD FORECASTING 3.1 Accuracy and Timeliness of the Met Office Short and Medium Term Forecasts.... (forecast v actual precipitation)...................................................................................... 9 3.2 Impact of Any Inaccurate Forecast...........................................................................9 3.3 Agency Telemetry and Outstation Robustness and Availability...........................10 3.4 Ability of Agency to Predict The Actual Flood Levels Using Their Current Models'(predicted v actual levels & flows)............................................................. 11 3.5 Issues Arising.......................................................................................................... 12 3.6 Recommendations................................................................................................... 13 4.0 FLOOD WARNING 4.1 Trigger/Threshold Levels for Warnings.................................................................15 4.2 Warnings Issued, Target Lead Times v Actual Lead Times..................................15 4.3 No. Properties Flooded Following Warning............................................................... (not including properties that also received severe warning)......................................18 4.4 No. Properties Flooded Without Warning............................................................. 18 4.5 No. Properties Not Flooded But Warned (not severe warning).............................18 4.6 No. Properties Flooded Following Severe Warning..............................................18 (do not include properties that also received warning)................................................18 4.7 No. Properties Flooded Without Severe Warning.................................................18 (do not include properties that also received warning)................................................18 4.8 No. Properties Not Flooded But Received Severe Warning................................. 18 4.9 Automatic Voice Messaging (AVM)......................................................................18 4.10 Floodline............................................................................................................... 19 4.11 Flood Wardens...................................................................................................... 19 4.12 Loud Hailers................................................................................................... ...20 4.13 Local Media (floof warning dissemination purposes only...................... ............ 20 4.14 Sirens and Public Address....................................................................................20 ENVIRONMENT AGENCY 089313 October/November 2000 Flood Event Report EA South West 4.15 Issues Arising.......................................................................................................... 20 4.16 Recommendations.................................................................................................. 22 5.0 EVENT IMPACT 5.1 Rainfall.......................................................................................................................23 5.2 River Flow (tides, surge, wind, waves)..................................................................25 5.3 Flooding (quantity, timing, duration, return periods - comparison with forecast.. 26 5.4 Source of Flooding................................................................................................... 34 5.5 No. Properties Not Flooded Due To Agency Defences.........................................35 5.6 No. Properties Not Flooded Due To Third Party Defences...................................35 5.7 No. Properties Flooded Due To Failure (Not Exceedence) Of Agency Defence ..35 5.8 No. Properties Flooded Due To Failure (Not Exceedence) Of Third Party Defences.......................................................................................................................35 5.9 No. Properties Flooded Due To Exceedence of Agency Defence Standards....... 35 5.10 List of Towns Affected Without Adequate Defences, Viability (cost benefit) of Scheme.........................................................................................................................36 5.11 Major Infrastructure Affected (roads, rail and where used as a secondary defence)........................................................................................................................41 5.12 Incidence of Repeat Flooding................................................................................41 5.13 Issues Arising..........................................................................................................42 5.14 Recommendations..................................................................................................42 6.0 EMERGENCY RESPONSE 6.1 Major Incident Plans Activated..............................................................................43 6.2 Gold and Silver Controls opened............................................................................ 43 6.3 Gold and Silver Controls with Agency Attendance............................................... 43 6.4 Agency (staffing, equipment and plant)..................................................................43 6.5 Adequacy of Agency Resources............................................................................. 44 6.6 Numbers of Staff Deployed.................................................................................... 44 6.7 Range of Functions and inter Regional Co-Operation (emergency response only) 45 6.8 Emergency Services, Local Authority, Other Response Organisations................45 6.9 Property Evacuated (no. of people) and Type (houses, hospitals, old peoples homes, factories etc.)................................................................................................. 45 6.10 Issues Arising..........................................................................................................46 6.11 Recommendations.................................................................................................. 47 7.0 PUBLIC RELATIONS 7.1 Links to the Media, Coverage by the Media (except for flood warning dissemination).............................................................................................................48 7.2 Number of Interviews by Media Type................................................................... 48 7.3 Issues Arising............................................................................................................48 7.4 Recommendations.................................................................................................... 49 8.0 INCIDENT SPECIFIC 8.1 Major Industry/Infrastructure................................................................................. 50 8.2 Legal Recommendations - Issue / Action / Ownership / Review Date.................50 8.3 Retrospective View by Others of