Work starts on dam safety work at Warnham Mill Pond Reservoir

Warnham Mill Pond. Photo: Brian Bateman.
Warnham Mill Pond. Photo: Brian Bateman.

Work has begun by the Environment Agency to improve the safety of the dam at the Warnham Mill Pond Reservoir, in Horsham.

The last routine inspection of the reservoir, located within the Warnham Nature Reserve, highlighted the need for work to be carried out to meet additional current stringent safety standards.

Following consultation with the community last year, a £1.1 million improvement scheme is being undertaken to ensure that those living downstream of the reservoir will be even better protected against a potential breach, or overtopping of the dam – even during the most extreme weather conditions.

The project will include:

installing a new steel sheet pile protective wall in front of the existing brick wall of the embankment

reinforcing the grass slope of the landward face of the dam (which acts as an auxiliary spillway in extreme conditions) and constructing a new brick wall around the Mill building

replacing the existing paving slab flood defence on top of the embankment with a new, purpose-built wall, which is also slightly higher

The key construction activity being undertaken is the installation of the steel sheet piles this autumn. The whole project is due to be completed by next spring.

The Environment Agency says that some trees will need to be removed from the rear of the embankment to enable these essential works to be completed. However, the impact of this will be minimised by careful landscaping, including cladding the steel sheet pile wall with natural materials.

Andrew Gilham, Area Flood & Coastal Risk Manager for the Environment Agency said: “These works are essential to strengthen the existing structure and ensure the safety of the dam which retains Warnham Mill Pond.

“The nature reserve is important to both wildlife and the local community, so as part of the works, we will be adding some new reed beds, to provide valuable new wildfowl habitat. Horsham District Council and the Environment Agency have a long history of working together at this site and this has been essential in developing this project.”

Evan Giles, Horsham District Council’s Parks Services Manager, said: “Warnham Nature Reserve is one of Horsham’s ‘hidden gems’. The Council has worked in close partnership with the Environment Agency, while planning this project in order to minimise the environmental and visual impact of these essential works. Every effort is being made to minimise disruption and allow our visitors normal access to the site and the extremely popular ‘Harvest Mouse’ Café.”