Multi-million pound flood alleviation scheme launches in Herne hill

A £4.2 million flood alleviation scheme to protect over 200 homes and businesses in Dulwich and Herne Hill from sewer and surface flooding has been completed today.

The innovative scheme, funded by Southwark Council, the Environment Agency and Thames Water, is the first of its kind in London to be delivered via a partnership approach and only recently received an award at this year’s Institution of Civil Engineers London Civil Engineering Awards.

The scheme is based in Dulwich Park, Belair Park and the Dulwich Sports Grounds in Southwark.

The project sees the three organisations working together to deploy a number of innovative techniques across the area to create a Sustainable Drainage System (SuDS).

Both Dulwich and Herne Hill have experienced notable floods in 1984, 2004 and 2007 each resulting in loss of residential property and business premises as well as public infrastructure.

The new scheme works with the landscape of the parks to capture surface water run-off and reduce flood risk in a sustainable way.

In a concerted effort to limit any disruption to the natural environment, engineers and landscape architects have worked to enhance the park through:

  • Building earth bunds and walls to temporarily contain or redirect surface water into existing lakes
  • Increasing storage capacity of existing lakes
  • Constructing below-ground storage areas to provide further capacity to store flood water which is released gradually back into the sewer network reducing the risk of sewer flooding
  • Creation of 3750m2 wetland and 6400m2 wildflower meadows to attract wildlife, enhancing local habitats and biodiversity

Counc. Darren Merrill, cabinet member for environment said: “The new flood alleviation scheme brings reassurance to the hundreds of residents and business owners in Dulwich and Herne Hill who were previously at risk of surface and sewer flooding.