Plots C and D show water levels and soil moisture data at a location inside the containment area. In the spring, snowmelt runoff flows into drainage ditches, which connect to the main catchment basin. Surface-water pumps remove runoff from the catchment basin. This problem was addressed through land surface drainage control. Three ground-water pumps are also used, which pump at about 2 gpm each to the catchment basin.
Pressure transducers measure water levels in the pumping wells.
A data logger records these measurements and controls the well pumps. If ground-water stays below an acceptable level, the well pumps are off. The surface-water pump is manually operated each day until all available water is pumped from the catchment basin. For the design calculations, surface-water pumping did not begin until the 1998 average daily air temperature rose above freezing. 28 days was the average period for 1998 and 1999.