B Detailed Summary Sheets and Mapping

B.1 DA01 - and

2012s6728 - Stage 1 SWMP (v1.0 Oct 2013) IV

Sevenoaks Stage 1 SWMP: Summary Sheet Drainage Area 01: Swanley and Hextable

Area overview

Area (km2) 9

Drainage assets/systems Type Known Issues/problems Responsibility

Sewers (combined, foul and Known problems of surcharging and overloaded sewers at Sewer Network Thames Water surface water) numerous locations across the drainage area

Flood risk

Receptor Source Pathway Historic Evidence

Thames Water sewers - Postcode Sector DA2 7 and BR8 There is historic evidence 7 from County Council of run off affecting Overland surface water flows routes from west to north carriageways Heavy rainfall resulting in east along College Road, Lower Road and School Lane. A: Hextable surface water run off and There are records of overloaded sewers The FMfSW also indicate that a likely route for overland hydraulic overload from flows originates in the Highland and continues north sewers causing internal and through Hextable. external flooding

Incidents of flooding caused Thames Water sewers - Postcode Sector BR8 7 and Cray by blocked drains Heavy rainfall resulting in Road Swanley surface water run off, There are records of overloaded drains/ gullies Ship Lane, Button Street and Road B: Swanley Village hydraulic overload from and sewers. sewers causing internal and Surface water flowing along Button Street in a north east external flooding Blocked Drains/ Gullies and north west direction towards School Lane with localised ponding in low lying areas

Records show heavy rainfall Thames Water sewers - Cray Road Swanley and blocked drains have Heavy rainfall resulting in caused flooding which has Laburnham Avenue and Hart Dyke Avenue surface water run off. been reported as affecting properties in Ladds Way, Large areas of ponding across Swanley South particularly A burst water main has also Edward Gardens and Hart C: Swanley West in low lying areas, such as Ladds Way and Edwards been described as a source Dyke Road. Garden of flooding Records show that a water Overland flow route indicated by the FMfSW Surface water Blocked Drains/ Gullies main burst on Laburnham flows in a north east direction with Road possible Avenue be a barrier to flows.

In 2009 on St Georges Road, anecdotal evidence Heavy rainfall resulting in St Georges Road suggests that there was 2 ft surface water run off and of water in the area and D: Swanley South overloaded sewers Overland flow route indicated by the FMfSW Surface water Kent Fire and Rescue were flows in a north east direction with London Road possible called due to the threat to Blocked Drains/ Gullies be a barrier to flows. properties. Flooding was due to blocked drains in the area. North Legend A Hexstable Β Swanley Village C Swanley West D Swanley South Main Rivers A IDB Maintained Watercourse Ordinary Watercourses Upper Medway IDB Historic Flooding* ! Surface Water ! Surface Water with blocked gullies/drains ! Sewer * Where an entire road has been Β highlighted in the historic layer; this ! does not mean that all the road has Groundwater flooded in the past but rather no specific location was identified in the records ! Fluvial received. ! Other/ Unknown ! Tidal Sewer Flooding Incidents** Number of flood occurences per postcode area

1 - 3 **Polygons only represent the C postcode area and not the flood 4 - 6 extent 7 - 8 < Client: Consultant:

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Key Plan 1:600,000

This document is the property of Jeremy Benn Associates Ltd. It shall not be reproduced in whole or in part, nor disclosed to a third party, without the permission of Jeremy Benn Associates Ltd. This map is based upon Ordnance Survey material with the permission of Ordnance Survey on behalf of the Controller of Her Majesty's Stationery Office (C) Crown Copyright. Unauthorised reproduction infringes Crown Copyright and may lead to prosecution or civil proceedings. 100019238. 2013 Scale 1:15,000 Sevenoaks Stage 1 SWMP Historical Flooding Please NOTE: Thames Water sewer flooding data was provided at postcode sector level (for e.g. TH13 2). Therefore even Swanley and Hextable though an entire area may be highlighted it does not mean that the location is at risk from sewer flooding. DA01