Improvements proposed to reduce surface water in Exeter

A series of essential improvements to reduce surface water on roads in Exeter are being put to Devon County Council's Cabinet this week (Wednesday 11 July).

Councillors are being asked to approve a proposed £450,000 scheme for the upper Northbrook area of Exeter, which is at high risk of surface water flooding.

Devon County Council has been leading an investigation on the risk of surface water flooding in Exeter, working in partnership with Exeter City Council, South West Water, the Environment Agency and Network Rail to prioritise areas for improvements.

The report before Cabinet is recommending a phased delivery of flood improvement works.

The first phase of work would focus on the Upper Northbrook catchment where high intensity rainfall overwhelms existing drainage systems. Improvements would mainly cover Beacon Lane and the George’s Close area of Whipton and Old Tiverton Road, which all have a history of surface water flooding going back over the last 50 years, with the most recent event being in October 2014.

The improvements are proposed at various locations in the Northbrook area, upstream of residential areas, in order to reduce runoff and restrict flows through built-up areas.
The main elements of the scheme include:

- Alterations to kerbing and parking at Guinevere Way/Round Table Meet to create a barrier to provide the Beacon Heath Children’s Centre with greater protection from flood water;

- Installation of a 300 metre long low-level wall along the cyclepath/footway from Beacon Lane to Bettys Mead playing fields;

- Highway drainage improvements to divert water into the Northbrook watercourse where there is spare capacity. This would include construction of a low earth bund at George's Close to create an above ground water storage area to reduce the risk of flooding from surface water;

- Provision of measures including flood doors, non-return valves and downpipe disconnections into the basement flats in Old Tiverton Road.

Councillor Roger Croad, Devon County Council Cabinet Member for the environment, said: “The investigative work has enabled the County Council to work with partner authorities to gain a better understanding of the risk of surface water flooding in the city. It has also highlighted the urgent need for the proposed flood alleviation works which will be prioritised within the city.

"Surface water flooding in the Northbrook area is exacerbated by the high intensity rainfall events being experienced more frequently. The scheme being proposed will aim to improve the current standard of protection up to a minimum of 1 in 75 year protection, and, for many properties, up to the 1 in 100 year protection.”

The business case for the scheme is currently being finalised and due to be submitted to the Environment Agency later this month (July) to request Defra Grant in Aid to support the funding of the scheme.

Detailed design is well advanced and the aim is to start construction this autumn.