I recently ran across a website promoting better groundwater management for a discreet, isolated, inter-mountain valley aquifer in California - the Borrego Valley in Northeastern San Diego County. http://www.borregowaterunderground.org/. The website owners are using this site as a call to arms to force the groundwater regulating entity therein - the Borrego Water District - to implement a groundwater plan they alledgedly drafted in 2002 but have never implemented. This site claims the groundwater levels have been falling at over 2 feet per year for the past 20 years, and this rate is increasing of late. Prediction is, based on projected extraction rates, another 30 years before the aquifer reaches a critical point. Other facts are: a population of 3,000; a 70 sqaure mile area; and withdrawing 24,000 AF per year. Sounds pretty serious - at least it did to me upon my first read.
The state's information on the valley is a bit different, but a lot more complete. They report an area of 240 square miles; annual average net use of 15,160 AF; average annual recharge of 8,300 AF; maximum saturated thickness of 4,500 feet in 3 stacked aquifers, but thinning a bit toward the valley flanks; specific yields ranging from 2% in the deepest formation to 25% in the shallowest; pre-development storage of 5,500,000 AF; total net depletion of groundwater (pre-development to 1980) of 330,000 AF - resulting in 1980 storage of 5,170,000 AF.
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