Trying to articulate water issues, provide discussion fodder, seek other ideas, broaden and educate a bit, and, and... well, solve the world's water problems.
Tuesday, May 24, 2011
A California Water Dialog
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.
Amazing how the scope of the problem changes when the rest of the picture is provided. In fact it was the lack of saturated thickness, recharge and aquifer storage information that got the better of me and caused me to find this out. There had to be more to this story. I had started reading the webpage in context of my local groundwater experience and was struck by the reported decline rates. These are worse than ours, which are locally considered too high. It wasn't until the scope of the overdraft in terms of the aquifer's storage volumes was discovered that this picture changed. While any decline is a problem of some degree and should be addressed (with accurate information if possible), and I applaud these folks for pointing out the situation, I have to also believe there are likely bigger problems to get after than this one, at this time - even in Borrego Springs, CA.