Construction of an attenuation dam to reduce flood risk to the village of Tilshead on Salisbury Plain
A site of Special Scientific Interest with archeological and ecological watching brief
10,000 cu of chalk imported from local stockpile to construct engineered chalk dam
Installation of over 675 tonnes of Armaflex matting
Working within military training areas with live ordinance
With an increased risk of flooding to the village of Tilshead on Salisbury Plain, Ringway, the Term Maintenance Contractor for Wiltshire Council, contracted MJ Church to construction an engineered dam to alleviate flooding in the area. The site of the dam is designated a SSSI (Site of Special Scientific Interest) and is also in the heart of the British Army’s training facilities on Salisbury Plain. MJ Church scope included earthworks, construction works associated with dam and returning the site back to post construction conditions.
The Tilshead Flood Attenuation Dam was constructed to hold up to 100,000m cu of flood waters. The dam is constructed with a chalk engineering Type 3 reduced fines layer to allow for water percolation. An Armourflex matting layer provides a heavy-duty, durable erosion protection system to the dam, which has been covered in a layer of topsoil to enable re-growth of local plant life.
Due to the restrictions of the SSSI, military conditions and potential archeological finds, MJ Church undertook special measures and processes for the project. These included: • Working with an Archeological working brief during the earthworks and excavation • Regular coordination with the Army to ensure minimal disruption to their routines and safe operations on the site and high security levels whilst live ordinance activity took place • Ensuring high levels of Ecological management by maintaining a barrier around the perimeter of the site to stop wild life moving back on the site, and maintain strict processes to avoid pillages and leachate within the site boundary.