These data are used to estimate the evaporation rates at the site and to determine compliance with groundwater quality standards. The size of the constructed wetland needed for evapotranspiration and percolation of effluent was determined by calculating several water balances for the site. Evaporation rates were estimated with the Penman method and were based on limited data available for the area. Subtracting the evapotranspiration and percolation from the rainfall yielded the net water loss from the site. Dividing the net water loss into the effluent volume gave an estimate of the required acreage.
Percolation is critical to successful operation of the project.
At least 1.1 inches of percolation per month is required at the projected flow rate. If percolation occurs at this rate, only 175 acres are needed to treat the effluent. If percolation does not occur, as much as 450 acres would be required. The Incline Village Wetlands Enhancement Facility includes a total of 770 acres of wetlands and uplands.