Enva carried out an Impermeable Area Survey across the villages of Dripsey, Coachford and Inishannon, Co. Cork
This survey was carried out in conjunction with a flow and load survey in order to determine the existing surface water run-off to the existing collection systems. This work was undertaken for a leading Consulting Engineering company. Impermeable Area Surveys are a central part of effective surface rainwater drainage and are conducted to create an understanding of the drainage of roofs, concrete and road surfaces and other impermeable areas. They are a vital tool in effective sewer network and flood management.
Most of the network in Dripsey, Coachford and Inishannon consists of a combined system where both foul sewage and storm water enters into the same system. Using dye tests on the impermeable surfaces (roads, roofs, hardstanding areas) it was possible to determine whether surface run-off on the specific area contributed to the flow in a combined sewer or if it ran to a dedicated storm sewer or soakaway.
Across the three villages, a total study area of 86ha was surveyed. Site maps were colour coded and labeled to display the type of surface and the verified destination. Co-ordinates of every manhole and gully across the villages were also recorded. A short timescale of 4 weeks was allowed for undertaking the works including digitizing of data and reporting to the client. The information collected from this study allowed detailed modelling of the areas to be undertaken and allowed proposals to be made for upgrading the networks.