Buckshole Reservoir Reservoir Safety Works

Scope of work

• A feasibility study to look at the various options of how the spillway capacity could be increased, including attending consultation meetings with various stakeholders
• Detailed design and tender documents
• Engineering support during construction
• Reservoir Act “Qualified Civil Engineer” to oversee the design and construction and certify the completed works
• Support to environmental and planning consultants to provide a coordinated service.

Project description

Buckshole Reservoir, a former water supply reservoir, is located just upstream of densely populated residential and commercial areas close to and within Hastings town centre.  Following statutory recommendations made in 2016, Stillwater Associates was commissioned by Hastings Borough Council to undertake a feasibility study of options for essential reservoir safety works.   A risk based approach was taken to determine an appropriate and cost effective scheme that would reduce the risk of dam failure as low as reasonably practicable (ALARP).

The scheme involved the construction of a new 4m wide, 90m long reinforced concrete channel as a direct replacement of the under-capacity existing spillway channel.  Stillwater Associates carried out physical modelling to optimise the various components of the channel, including the bespoke stilling basin at the downstream end.  The new channel, which was successfully completed in November 2022, will significantly reduce the risk of out of channel flow and any resulting damage/breach of this Category A reservoir.

The project also included the design and installation of a new 300mm diameter siphon draw-off pipeline cored through the existing overflow weir to allow the reservoir to be drawn down for maintenance purposes or in response to an emergency.  The siphon pipeline has been designed to provide the required drawdown capacity for Buckshole Reservoir in accordance with the 2017 Environment Agency drawdown guidance.