SWRBD CFRAM Study
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SWRBD CFRAM Study Inception Report - Unit of Management 20 September 2013 Office of Public Works SWRBD296235 IWECFRAM CCW StudyR005 C 296235/IWE/CCW/R005/C February 2013 Inception Report - Unit of Management 20 September 2013 Office of Public Works Jonathan Swift Street Trim Co. Meath Mott MacDonald, 5 Eastgate Avenue, Eastgate, Little Island, Cork, Co Cork, Ireland T +353 (0)21 4809 800 F +353 (0)21 4809 801, W www.mottmac.com SWRBD CFRAM Study Issue and Revision Record Revision Date Originator Checker Approver De scription A May 2012 M. Piggott B. O’Connor F. McGivern Initial Issue T. Donovan B November 2012 M. Piggott B. O’Connor F. McGivern Revised Issue T. Donovan C February 2013 M. Piggott B. O’Connor F. McGivern Revised Issue A. Lambe D September 2013 T. Donovan B. O’Connor F. McGivern Revised Issue Please read carefully the following statements and conditions of use of the data, contained in this report. 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This document is issued for the party which commissioned it Copyright and for specific purposes connected with the above-captioned project only. It should not be relied upon by any other party or Copyright - Office of Public Works. All rights reserved. No part used for any other purpose. of this report may be copied or reproduced by any means without prior written permission from the Office of Public Works. We accept no responsibility for the consequences of this document being relied upon by any other party, or being used Legal Disclaimer for any other purpose, or containing any error or omission which is due to an error or omission in data supplied to us by other This report is subject to the limitations and warranties contained parties in the contract between the commissioning party (Office of Public Works) and Mott MacDonald Ireland. This document contains confidential information and proprietary intellectual property. It should not be shown to other parties without consent from us and from the party which commissioned it. Mott MacDonald, 5 Eastgate Avenue, Eastgate, Little Island, Cork, Co Cork, Ireland T +353 (0)21 4809 800 F +353 (0)21 4809 801, W www.mottmac.com SWRBD CFRAM Study Content Chapter Title Page 1. Introduction 1 1.1 Aims and Objectives _________________________________________________________________ 1 1.2 Description of the South Western Study Area ______________________________________________ 2 1.3 Unit of Management 20 _______________________________________________________________ 4 1.4 Areas for Further Assessment _________________________________________________________ 4 1.5 SW CFRAMs Project Delivery __________________________________________________________ 4 2. Detailed Methodology 6 2.1 Data Collection _____________________________________________________________________ 6 2.2 Hydrometric Data ___________________________________________________________________ 6 2.3 Meteorological Data _________________________________________________________________ 7 2.4 Coastal Data _______________________________________________________________________ 7 2.5 Survey Data (including LIDAR & IFSAR) _________________________________________________ 7 2.6 Environmental Data _________________________________________________________________ 8 2.7 Receptor Data _____________________________________________________________________ 10 2.8 Flood Event Data __________________________________________________________________ 12 2.9 Flood Defence Asset Data ___________________________________________________________ 12 2.10 Outstanding Data __________________________________________________________________ 13 2.11 Unavailable Data ___________________________________________________________________ 13 3. Survey Requirements 14 3.1 River Channel Survey _______________________________________________________________ 14 3.2 Floodplain Survey __________________________________________________________________ 15 3.3 Flood Defence Asset Condition Survey _________________________________________________ 15 3.4 Property Level Survey _______________________________________________________________ 17 4. Preliminary Hydrological Assessment 18 4.1 Hydrometric Data Review ____________________________________________________________ 18 4.2 Meteorological Data Review __________________________________________________________ 20 4.3 Coastal Data Review _______________________________________________________________ 22 4.4 Physical Catchment Descriptor Review _________________________________________________ 23 4.5 Historical Flood Events ______________________________________________________________ 24 4.5.1 Review of Historical Flood Data _______________________________________________________ 24 4.5.2 Historical Flood Event Summaries _____________________________________________________ 27 4.5.3 Selection of Calibration/Verification Events ______________________________________________ 29 4.6 Flooding Mechanisms _______________________________________________________________ 30 5. Detailed Method Statement 31 5.1 Flood Risk Review Approach _________________________________________________________ 31 5.1.1 Site Visits ________________________________________________________________________ 31 5.1.2 Flooding History ___________________________________________________________________ 31 5.1.3 Flood Risk Review Report____________________________________________________________ 31 5.2 Survey Approach __________________________________________________________________ 31 5.2.1 Channel and Structure Survey ________________________________________________________ 31 5.2.2 Defence Asset Condition Survey ______________________________________________________ 31 296235/IWE/CCW/R005/D 296235-IWE-CCW-R005-D HA20 SWRBD CFRAM Study 5.3 Hydrology Approach ________________________________________________________________ 32 5.3.1 Overview _________________________________________________________________________ 32 5.3.2 HEP Conceptualisation ______________________________________________________________ 34 5.3.3 Rating Review _____________________________________________________________________ 35 5.3.4 Approach for Gauged Fluvial Locations _________________________________________________ 36 5.3.5 Approach for Ungauged Fluvial Locations _______________________________________________ 38 5.3.6 Approach for Tidal Locations _________________________________________________________ 39 5.3.7 Future Scenarios ___________________________________________________________________ 41 5.4 Hydraulic Analysis Approach _________________________________________________________ 42 5.5 Flood Risk Assessment (FRA) ________________________________________________________ 46 5.5.1 Social Risk _______________________________________________________________________ 46 5.5.2 Risk to the Environment _____________________________________________________________ 46 5.5.3 Risk to Cultural Heritage _____________________________________________________________ 46 5.5.4 Risk to the Economy ________________________________________________________________ 47 5.5.5 Indicators of Vulnerability ____________________________________________________________ 47 5.5.6 Risk Assessments __________________________________________________________________ 47 5.6 Strategic Environmental Assessment (SEA) ______________________________________________ 47 5.6.1 Phase I Screening Assessment _______________________________________________________ 47 5.6.2 Phase II Constraint and SEA Scoping Study _____________________________________________ 48 5.6.3 Phase III Option Appraisal Study ______________________________________________________ 48 5.6.4 Phase IV SEA Report _______________________________________________________________ 49 5.6.5 Phase V Update of SEA Report _______________________________________________________ 49 5.6.6 Production of the SEA Statement ______________________________________________________