B.4 DA04 Hythe and Horn Street

2011s5468 - Folkestone and Hythe Stage 1 SWMP_TC.doc VII

Folkestone and Hythe Stage 1 SWMP : summary and recommendations Drainage Area 04

Area overview

Area (km2) 6.3

Drainage assets/systems Type Known Issues/problems Responsibility

There are recorded incidents of flooding from fluvial sources Brockhill Stream Main River on Brockhill Stream in West Hythe prior to the construction Environment Agency of the defence scheme in 2000.

There were no recorded incidents reported on this stretch of Royal Military Canal Main River Environment Agency water.

No recorded incidents of flooding from fluvial sources on the Saltwood and Mill Lease Stream Main River Environment Agency Saltwood and Mill Lease Stream

Historically there are fluvial issues on Spring Lane, Cliff Seabrook Stream Main River Environment Agency Road and Seabrook Road

Drains Ordinary Watercourse Some historic risk within vicinity of drains Kent County Council

Sewers (combined, foul and Known problems of surcharging at locations across the Sewer network Southern Water surface water) drainage area.

Flood risk

Receptor Source Pathway Historic Evidence

Southern Water sewers. The is historic evidence of Heavy rainfall resulting in flooding in this area, both flooding from overloaded The overland flow route comes from the north - north west caused by fluvial sources A: Orchard Valley sewers and Brockhill Stream following the route of the Brookhill Stream towards London (there has since been flood and/or Ordinary Road where it reaches Orchard Valley. The elevated ground defence improvements) and Watercourses levels of the Royal Military Canal may act as a boundary to by sewers overloading. flow routes.

The is historic evidence of flooding in this area, caused High tides and storms Southern Water sewers. by coastal sources (there resulting in sewers has since been coastal B: St Hilda's Road, Hythe tidelocking and wave Wave overtopping results in localised ponding of water protection improvements, overtopping around West Parade, Ormonde and Victoria Roads. 2004) and by sewers backing up due to tide locking.

There is history of flooding in Blocked culvert along Flooding along the valley of the watercourse, accumulating this area due to surface C: Mill Road and Station Road Saltwood and Mill Lease in low spots around Station and Mill Road and East Street. water, a result of a blocked Stream culvert (which is main river).

Southern Water sewers resulting in runoff along localised There are recorded incidents roads. Heavy rainfall resulting in of flooding from overloaded D: Cannongate Road, Hythe overloaded sewers sewer networks and runoff Runoff from land to west of properties along Blackhouse from adjacent rural land Hill.

Heavy rainfall resulting in There are recorded incidents Southern Water sewers and flow paths along Spring Lane overloaded sewers, runoff of flooding from fluvial E: Spring Lane, Horn Street (the deep FMfSW also shows this as a key flow route for and flooding from local sources and overloading of surface water) watercourse the sewer network. There is a history flooding Southern Water sewers. from a variety of sources, Heavy rainfall resulting in coastal (there has since overloaded sewers and Records of fluvial flooding are disconnected from been coastal protection surface water watercourses, which suggests these may be surface water improvements, 2004), F: Seabrook runoff/ponding. Potentially incidents, the pathway for which is localised ponding along surface water, fluvial, fluvial sources but records Seabrook Road / Sandgate Esplanade. groundwater (although are unclear. Wave location of fluvial and overtopping. Wave overtopping results in localised ponding and flow groundwater events suggest routes along Seagate Esplanade. this may be surface water) and overloaded sewers.

There are numerous Heavy rainfall resulting in incidents of sewer flooding G: Various (sewer) Southern Water sewers overloaded sewers across the drainage area (both internal and external).

Receptor relates only to residual risk shown by As well as showing flow routes along watercourse pathways, FMfSW, and aside from Heavy rainfall resulting in H: Various (surface water) the FMfSW also suggests ponding to the north of the Royal locations mentioned above, surface water runoff Military Canal there are no records of historic flooding to substantiate risk.

Summary of Location-specific Actions

Area of benefit Location of action Action Action owner Priority

1. A CCTV study to investigate the condition of drains and gullies.

2. Ensure gullies, drains, sewers are cleared and cleansed within the same day. Signposting to inform locals of plans for Cannongate Road/Sene 1 & 2 = Short Term Cannongate Road/Sene Park/Cliff gully and sewer jetting, Park/Cliff Close, KCC Close, Hythe would help to Brockhill, Hythe 3 = Medium Term demonstrate that the RMAs were working together to help and improve the current problems.

3. Consider use of property resilience and resistance measures

Divert surface water runoff by using land Cannongate Road/Sene Park/Cliff Land west of properties raising or ditches to divert KCC Long Term Close, Hythe along Blackhouse Hill runoff to Saltwood and Mill Lease Stream

1. Commission modelling study to better understand risk within Horn Street Spring Lane, Horn Street Spring Lane, Horn Street KCC 1 & 2 = Long Term 2. Feasibility options could include green infrastructure along Spring Lane North

Legend Main River (EA) - open channel Main River (EA) - culverted Ordinary Watercourse - open channel E Ordinary Watercourse - culverted Surface Water Sewer (Southern Water) Foul Sewer (Southern Water) D Combined Sewer (Southern Water) Receptors C A Orchard Valley F Β St Hilda's Road, Hythe C Mill Road and Station Road A D Cannongate Road, Hythe E Spring Lane, Horn Street F Seabrook G Various (sewer)* H Various (surface water)* * Illustrations not located on the map, as there are several receptor areas across the drainage area

Client: Partners: Β

Consultant:

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. Scale 1:16,000

Folkestone and Hythe SWMP Stage 1 Watercourses and Drainage Systems 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. 2012 DA04 North

Legend Main River (EA) - open channel Main River (EA) - culverted Ordinary Watercourse - open channel Ordinary Watercourse - culverted E Receptors A Orchard Valley Β St Hilda's Road, Hythe D C Mill Road and Station Road D Cannongate Road, Hythe C E Spring Lane, Horn Street * Illustrations not located F Seabrook F on the map, as there are Various (sewer)* several receptor areas G across the drainage area A H Various (surface water)* Historic flooding (other RMAs) ! Other/Unknown ! Fluvial Flooding ! Groundwater ! Combined ! Surface Water Β ! Sewer Sewer flooding incidents (Southern Water)* Number of flood occurences per postcode area 1 - 5 * Polygons only represent the 6 - 15 postcode area and not the flood >16 extent

Client: Partners:

Consultant:

Folkestone and Hythe SWMP Stage 1 Historic Flooding 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. 2012 DA04 North

Legend Main River (EA) - open channel Main River (EA) - culverted Ordinary Watercourse - open channel Ordinary Watercourse - culverted ") Education (Nursery, Primary School, Higher Education) FG Hospital # Emergency Services (Ambulance, Fire and Police Stations) 0.3m deep FMfSW 1 in 200yr AEP > 0.3m deep

Β Client: Partners:

Consultant:

Folkestone and Hythe SWMP Stage 1 Surface Water and Critical Infrastructure 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. 2012 DA04