Grabhorn Aquifer Storage and Recovery

During the winter, when water supplies are plentiful, TVWD stores treated drinking water underground in the aquifer surrounding the Grabhorn Aquifer Storage and Recovery (ASR) well. During the summer, the stored water is pumped out of the well to augment other sources to help meet peak-summer water demands. This ASR is able to supply our District with 3 million gallons a day for approximately 90-100 days.

The Grabhorn ASR well is capable of storing in excess of 350 MG of treated water. In comparison, the combined total capacity of TVWD's existing 23 storage reservoirs is about 67 MG. This seasonal supply helps meet peak-summer water demands and reduce the District's cost for purchased water.

During the 2020 fiscal year, TVWD injected about 74 million gallons of water in to the ASR, and withdrew about 18 million gallons from the ASR.