Tim Ross’s report to Borrego Water District board on Monitor Wells 4 and 5
26 September 2007.
Tim Ross, PhD, is an engineering geologist with the California Department of Water Resources, Southern Division, who has been involved in the siting, drilling, and interpretation of data from monitoring wells built over the past few years by the Borrego Water District (BWD) with state grant money. Below are highlights from his remarks to the BWD board regarding results from Monitor Wells 4 and 5 in the Borrego valley.
- Originally at least some wells in the valley were “flowing artesian wells;” so there was no need to pump water for irrigation.
- The northern and southern halves of the basin are separated and are “different animals.” The northern half, where agriculture is located, both holds and will produce more water.
- Water levels have been going down at 2.5 to 3 ft/yr and give the “best picture” of the state of the aquifer.
- Historically, predictions of water use in the valley have all been wrong and on the low side. Demand for water will only grow over time.
- No one method contained in the BWD groundwater management plan will, by itself, fix the overdraft; but all of them together will help to mitigate it.
- Metered well data from agricultural and golf course irrigation wells would help to better define the aquifer; but farmers and golf course owners refuse to share it.
- 80% of all wells in the valley now draw water from approximately 100 feet below surface.
- Next 100’ of water in the aquifer will last approximately 30 – 50 years at present rate of use. May run into water quality problems at depth.
- Without getting both agriculture and golf courses out of the valley, the aquifer will never be in equilibrium with natural recharge.
See also: More Bad News for Borrego
10/08/07