Conwy Local Flood Risk Management Strategy Strategy Document February 2013 Conwy County Borough Council ConwyECP Local ECP ECPFlood ECP RiskECP F:\DCIM\Draft Conwy Strategy DRAFT V4.docx Management Strategy24 July 2012 Strategy Document 2013 - 2017 February 2013 Conwy County Borough Council G.B. Edwards BEng (Hons) CEng FICE Head of Environment, Roads and Facilities Service, Mochdre Offices, Conway Road, Mochdre, Colwyn Bay, LL29 5AB. Tel. (01492) 574000 Fax. (01492) 575199 Conwy Local Flood Risk Management Strategy Issue and revision record Document Title Local Flood Risk Management Strategy Version 130225.TP11A.LFRMS.02 Status Approved Document version Notes Date 0.2 Cabinet Issue February 2013 Signature Name Date K Burton 25/02/13 Prepared by C Probert S Wasik 25/02/13 Checked by D Rowlands Approved by G Edwards 25/02/13 This document is issued for the party which commissioned it We accept no responsibility for the consequences of this and for specific purposes connected with the above-captioned document being relied upon by any other party, or being used project only. It should not be relied upon by any other party or for any other purpose, or containing any error or omission which used for any other purpose. is due to an error or omission in data supplied to us by other parties. This document contains proprietary intellectual property. It should not be used by other parties without consent from us and from the party which commissioned it. Copyright of Conwy County Borough Council Conwy Local Flood Risk Management Strategy We are happy to provide this information in alternative formats A Please Contact: HR and Equality Officer E-mail: [email protected] Telephone: 01492 576225 Conwy Local Flood Risk Management Strategy Content Chapter Title Page Glossary and Abbreviations of words and phrases commonly used in flood and coastal erosion risk management __ 10 Executive Summary i 1. Introduction 1 1.1 Introduction ________________________________________________________________________ 1 1.2 Strategic Environmental Assessment ____________________________________________________ 2 1.3 Habitats Regulations Assessments ______________________________________________________ 2 2. Guiding Principles 3 3. Legislative Context 4 3.1 History of Flood Risk Management ______________________________________________________ 4 3.2 The Flood and Water Management Act 2010 ______________________________________________ 5 3.3 The Pitt Review _____________________________________________________________________ 5 3.4 The Flood Risk Regulations 2009 _______________________________________________________ 5 3.5 The National Strategy for Flood and Coastal Erosion Risk Management _________________________ 6 3.6 Other Legislation ____________________________________________________________________ 7 4. Flood Risk in Conwy 9 4.1 Introduction ________________________________________________________________________ 9 4.2 Local Flood Risk ____________________________________________________________________ 9 4.3 Types of Flooding __________________________________________________________________ 12 4.3.1 Surface Water Flooding (pluvial) _______________________________________________________ 12 4.3.2 Groundwater Flooding ______________________________________________________________ 14 4.3.3 Fluvial Flooding ____________________________________________________________________ 14 4.3.4 Sewer or Highway Flooding __________________________________________________________ 17 4.3.5 Reservoir Flooding _________________________________________________________________ 17 4.3.6 Coastal Flooding ___________________________________________________________________ 18 4.4 A Combination Event _______________________________________________________________ 18 4.5 Coastal Squeeze ___________________________________________________________________ 19 4.6 Factors Increasing Flood Risk _________________________________________________________ 20 4.7 Methodology for Identifying Areas of Risk ________________________________________________ 20 4.8 Limitations of data __________________________________________________________________ 21 5. Climate Change 23 5.1 Climate Change ___________________________________________________________________ 23 5.2 Climate Change in Wales ____________________________________________________________ 24 6. Regional and Local Plans 25 6.1 Conwy County Borough Council Preliminary Flood Risk Assessment __________________________ 25 6.2 Conwy and Clwyd Catchment Flood Management Plan _____________________________________ 26 6.3 River Dee Catchment Flood Management Plan ___________________________________________ 26 6.4 North West Wales Catchment Flood Management Plan _____________________________________ 27 6.5 West of Wales Shoreline Management Plan 2 ____________________________________________ 27 6.6 North West England and North Wales Shoreline Management Plan SMP2 ______________________ 28 Conwy Local Flood Risk Management Strategy 6.7 River Basin Management Plan – Western Wales River Basin District and Dee River Basin District ____ 28 6.8 Conwy Tidal Flood Risk Assessment ___________________________________________________ 29 6.9 Conwy Strategic Flood Risk Assessment ________________________________________________ 29 6.10 Multi Agency Flood Plans ____________________________________________________________ 30 6.11 The Tidal Clwyd Flood Risk Management Strategy ________________________________________ 30 7. Managing the Likelihood of Flooding 31 7.1 Responsibilities of Environment Agency Wales ___________________________________________ 33 7.1.1 Coastal Erosion Risk Management Authority _____________________________________________ 34 7.1.2 Emergency Planning ________________________________________________________________ 34 7.1.3 Main Rivers _______________________________________________________________________ 34 7.1.4 Coastal Flooding ___________________________________________________________________ 35 7.1.5 Reservoirs ________________________________________________________________________ 35 7.1.6 Single Environment Body for Wales ____________________________________________________ 36 7.2 Powers and Responsibilities of Conwy County Borough Council ______________________________ 37 7.2.1 As a Lead Local Flood Authority _______________________________________________________ 38 7.2.2 Environment and Technical Services ___________________________________________________ 39 7.2.2.1 Strategic Leadership ________________________________________________________________ 39 7.2.2.2 Recording of Flood Incidents _________________________________________________________ 39 7.2.2.3 Investigation of Flood Incidents________________________________________________________ 41 7.2.2.4 Register of Flood Risk Assets _________________________________________________________ 44 7.2.2.5 Sustainable development ____________________________________________________________ 47 7.2.2.6 Designating Assets _________________________________________________________________ 47 7.2.2.7 Meeting the Flood Risk Regulations ____________________________________________________ 47 7.2.2.8 Consenting Works on Ordinary Watercourses ____________________________________________ 48 7.2.2.9 As SuDS Approval Body (SAB) ________________________________________________________ 48 7.2.2.10 Environment and Technical Services other Duties _________________________________________ 50 7.2.3 In Carrying out Emergency Planning ___________________________________________________ 53 7.2.4 As a Planning Authority ______________________________________________________________ 56 7.3 Dŵr Cymru – Welsh Water ___________________________________________________________ 58 7.3.1 Transfer of Responsibilities ___________________________________________________________ 59 7.3.2 Flood Risk Management _____________________________________________________________ 59 7.3.3 Reducing Sewer Flooding ____________________________________________________________ 60 7.3.4 System of public sewers and works ____________________________________________________ 60 7.3.5 Reservoir Undertaker _______________________________________________________________ 61 7.4 Conwy County Borough Council Environment, Roads and Facilities Service Department ___________ 62 7.4.1 Responsibility to maintain the Highways _________________________________________________ 62 7.4.2 Adoption of SuDS __________________________________________________________________ 62 7.4.3 Powers to deliver works _____________________________________________________________ 62 7.4.4 Response in an Emergency Flooding Event ______________________________________________ 62 7.5 North and Mid Wales Trunk Road Agency on behalf of the Welsh Government ___________________ 64 7.6 Powers and Responsibilities of Conwy’s Citizens (Businesses, Landowners and Local Households) __ 65 7.6.1 Property Owners and Residents _______________________________________________________ 65 7.6.2 Riparian Ownership ________________________________________________________________ 66 7.6.3 Utility and Infrastructure Providers _____________________________________________________ 66 7.6.4 Reservoir Undertaker _______________________________________________________________ 67 8. Local Outcomes and Measures 68 8.1 Conwy County Strategic Outcomes ____________________________________________________ 68 Conwy Local Flood Risk Management Strategy 8.2 Potential Measures _________________________________________________________________ 71 8.3 Adopt Natural Flood Risk Management