Ramsden reservoir was constructed in the Victorian era and is one of four reservoirs in the Holme Valley that supply Holmbridge Water Treatment Works, which in turn provides mains water to the major urban populations of Dewsbury, Batley and Heckmondwike.
To ensure continued compliance with the Reservoirs Act 1975, Yorkshire Water identified a need to upgrade the existing spillway to account for a 1 in 500 year flood event.
ABG was invited to design a retaining wall structure which allowed the embankment next to the spillway to be steepened. The Holme Valley is popular with anglers, walkers and cyclists and the works had attracted a lot of interest from the local community.
The solution using ABG Webwall Geocell was selected since it met the brief of exerting no additional pressure to the back of the reinforced concrete spillway wall, while providing an attractive vegetated finish.
Webwall geocell offered a further advantage since it uses existing fill from the site, so reduces the need to export excavated material and import structural fill. This significantly reduces the number of vehicle movements around the site and avoids costly removal of spoil to landfill.
For this project the Webwall geocell was produced in a bespoke colour to the clients requirements. The colour was selected to blend into the background of the local soil and heathers, minimising the visual impact of the wall whilst the vegetation was establishing.
ABG designed the structure incorporating Trigrid EX Geogrid, a polyolefin coated polyester geogrid that gives high strength at low strain.
ABG Fildrain was used to ensure sufficient drainage within the structure and remove the need to import any high-cost drainage aggregates.
Webwall geocell is easy to install, and the structure was built more quickly than expected. After construction, intentionally minimal planting was undertaken so that the majority of the wall was left to self seed from the local flora, meaning a low maintenance finish in harmony with the local environment was achieved.
After 6 months the geocellular Webwall facing was almost completely obscured by the established vegetation.
The ABG Service
The contractor had no prior experience of using Webwall, so ABG provided installation support to train the site team and supervise the first few days of installation.
Contact ABG to explore how Webwall geocell could assist your client to achieve a sustainable, cost-effective and carbon neutral solution.