During extreme rainfall events the town of Bodmin was regularly flooded due to the limited capacity of the Leat (stream) passing through the town. Halcrow, working for the Environment Agency, designed a scheme which included a flood storage dam above the town. The dam incorporated a culvert which allowed the normal flow through the town but which restricted the flow during flood events. Water then backs up and is stored behind the new dam, temporarily flooding farmland.
During flood events which exceed the design there is a possibility that the dam will overtop. To allow for this a section of the dam crest and the downstream face was reinforced with a layer of Open Stone Asphalt placed on geotextile.
1,000 m2 erosion protection provided
125mm OSA placed on geotextile
Topsoil layer placed over the surface of OSA to promote establishment of vegetation.