FLOOD RISK ASSESMENT. FOR PROPOSED REFURBISHMENT OF NGN’S CURRENT “CARCROFT AGI” AT (NEAREST ADDRESS): 26 SKELLOW ROAD, CARCROFT, DONCASTER, SOUTH YORKSHIRE, DN6 8HQ FOR NORTHERN GAS NETWORKS Project Ref: 50097-CARCROFT Issue: 01 Date: FEB 2016 Prepared By: L.Mace B.Eng. (Hons) GGP Consult Ltd Consulting Engineers Priory Tec Park Saxon Way Hessle HU13 9PB United Kingdom Tel: +44 (0) 1482 627963 Fax: +44 (0) 1482 641736 Email: [email protected] CONTENTS 1. Brief 2. Description of Existing Site 3. Proposed Development 4. Flood Risk Assessment 5. Summary 1.0 BRIEF GGP Consult has been requested by the client, Northern Gas Networks, to prepare a flood risk assessment for the refurbishment work at NGN’s existing Carcroft site off Skellow Road, Carcroft, Doncaster, DN6 8HQ. The purpose of the assessment is to demonstrate compliance with local planning policy as outlined within the Doncaster County Council Flood Risk Assessment (SFRA) 1 and the National Planning Policy Framework (NPPF) 2. This statement should be read in conjunction with planning drawings and the planning application form, most notably drawings: GGP-50097-CARCROFT-PLANNING-001 – Site Location Plan GGP-50097-CARCROFT-PLANNING-003 – Proposed Site G.A GGP-50097-CARCROFT-PLANNING-005 – Proposed Road Layout/Levels & Drainage 2.0 DESCRIPTION OF EXISTING SITE The existing site is currently active as a PRI gas take off site, been used primarily to reduce gas pressures so that they can be distributed safely within the local community to homes and businesses. The proposed refurbishment will take place within the existing NGN Carcroft site. The current site is approximately 1385m2 in total area. Once completed the updated site will reduce in overall size to approx. 1337m2. The existing floor space area within the existing site equates to roughly 145m2, to which no drainage is currently active. In terms of impermeable area the existing site has approximately 250m2 of undrained hardstanding. National Grid Reference (Centre of Site) = 454100 E, 409667 N 3.0 PROPOSED DEVELOPMENT The proposed development is to incorporate a new road layout, which is intended to be take surface water run from the road via road gulley’s to the existing S.W drain noted on drawing No “GGP-50097-CARCROFT-PLANNING-005 – Proposed Road Layout/Levels & Drainage”. The approximate area of the new road is 361.0m2. In terms of floor space, the new site proposal will see a reduction from the existing site layout, with an approximate area of a 30.0m2. This is a reduction of 85.0m2 from the existing site. In terms of importable area the proposed site will have approximately 171m2 of undrained hardstanding (Not including the road). 4.0 FLOOD RISK CLASSIFICAITON After review of the global flood zone mapping, in accordance with Doncaster SFRA, the mapping indicates that the site lies just outside of flood zone 3.0 – area E55. (See diagram below – Refer to Appendix A for full Flood zone mapping for this area) Location of NGN site After review of the S.W flood map for the Carcroft Area, it is also evident that the site lies outside of the risk of any S.W water flooding, however surface water flooding does occur to the North of the site on Skellow Road. (See diagram below – Refer to Appendix B for full S.W mapping for this area) Location of NGN site 5.0 Summary From review of the mapping data available we believe that the site lies just within flood zone 1, and that it is not at risk of surface water flooding. It should be noted that mitigation has also been made in the design for potential high risk electrical items on the site such as the generator, E&I kiosk and incoming electrical supply kiosk. All these are to have a floor level which is a minimum of 200mm above the proposed site level. APPENDIX A – FLOOD ZONE MAPPING (CARCROFT) APPENDIX B – SURFACE WATER FLOOD MAPPING (CARCROFT) .