When Paramount first wanted to put a Freshwater Pond at this location they ran into a few issues with ground water. To mitigate these issues, the Owner and Engineer designed the pond to have an subdrain drainage layer (Double Sided Geocomposite) between the excavated ground and the Reservoir Liner.
The goal of having the subdrain layer down first was to aid the subdrain system with groundwater mitigation and as a bonus provide protective underlay to the reservoir liner. But, the next challenge was that groundwater was observed coming in at higher elevations up the slopes of the reservoir.
The new design was to include excavating finger drains up to the problematic areas to help direct more water towards the subdrain system along the floor and eventually move it towards the subdrain sump area. Prior to our crew mobilizing to site, Layfield Project Manager did a site visit and was able to help identify concerning subgrade areas, caused by groundwater seepage along the slopes, that may lead to eventual failures underneath the liner system.
After the Owner and Engineer reviewed the situation further it was determined that more finger drains needed to be installed throughout the problematic areas prior to our Layfield Crew mobilizing to site.
As a result of the Layfield Site visit and a thorough discussion with the Client. It was determined that additional Finger Drains be installed in specific locations to help with the water mitigation. Now to date, Layfield has completed the Geocomposite Subdrain Layer and the Enviro Liner 6160 Reservoir Liner system. The pond is scheduled to go into service Spring of 2018.