Blackmoorfoor Reservoir is a raw water catchment reservoir. During extreme rainfall events a significant discharge of water flows down the spillway. Beyond the spillway there was an open channel which was being eroded by the high flows.
The solution was to re-profile the channel to the trapezoidal shape of the spillway channel and line it with 200mm Open Stone Asphalt. A filter layer of geotextile was placed beneath the OSA.
Low level flow capacity provided by pipes beneath erosion protection
Main channel protected with 200mm OSA placed on geotextile
Topsoil brushed into surface of OSA to promote establishment of vegetation over OSA