Flood basins proposed for Bowling Green Road and Heath Lane, Thatcham

Two more detention basins have been proposed for Thatcham as part of the North Thatcham Flood Alleviation Scheme.

The applications, which have been signed off by the Environment Agency, were validated on January 5.

The locations in question are Bowling Green Road and Heath Lane, in addition to the two pre-existing basins built in the last seven years.

The drainage basin application for Bowling Green Road is expected to be determined in early March, with Heath Lane expected in the beginning of April.

Flood alleviation schemes have already been constructed, one at Tull Way and Cold Ash Hill in the North of Thatcham, and were completed in 2018 and 2014 respectively.

A design and access statement, which has been commissioned by West Berkshire Council, states the reasons why two additional drainage basins are needed in Thatcham, as well as where they will be and how much water they can capture.

The detention basin at Bowling Green Road, with an area of 0.2 hectares, will provide approximately 2,750 metres cubed of flood storage.

The basin at Heath Lane will have an area of 0.35 hectares and will provide approximately 5,300 metres cubed of flood storage.

The maximum embankment height for this basin equates to 0.6 metres.

Revisiting the town’s history with flooding, the design and access statement mentions the events in the summer of 2007, which caused widespread surface water flooding.

It stated that this affected “at least 1,100 houses” and resulted in severe economic losses to both residents and businesses”.

It was noted as “frequently caused by a combination of runoff from the rural catchment to the north of the town and urban overland flows”.

The most recent case referenced is the floods in December 2013 to March 2014 when the town, “like many other parts of the county, experienced an unprecedented period of wet weather”.

Many studies have been undertaken to assess the potential improvements for flood protection and management. West Berkshire Council has now undertaken a Surface Water Management Plan (SWMP) for Thatcham.

The SWMP sets out an Action Plan which identified a number of urban and rural overland flow routes, which had a significant impact on Thatcham.

It was found that one of the main surface water flow routes was along Harts Hill Road and Stoney Lane where flood depths and velocities were “life-threating”.

The proposed flood alleviation schemes, at both locations, will be constructed at the same time which is hoped will “significantly” reduce the impact of disturbance.

During this time construction vehicles will be travelling in and out of the sites, causing movements along Heath Lane, Bowling Green Road, Floral Way and the A4, Bath Road.

For the most part, it has been proposed that the bunds will be constructed from “site-won material”.

Thames Water has been consulted and has provided funding.

It has also been stated that the local community, via Thatcham Town Council and Thatcham Flood Forum, have been “actively involved” and “supportive” of the scheme.

More information can be accessed on the West Berkshire Council planning portal, including archaeological and ecological statements and construction traffic routes.

Type 21/03154/FUL into the planning portal for Bowling Green Road and 21/03135/COMIND for Heath Lane.