Sheep Water Quality
Last updated 8/7/2018 at 11:40am
This summer’s water quality testing during the annual Bighorn Sheep Count in the Anza-Borrego Desert State Park showed that levels of Total Dissolved Solids (TDS) paralleled the fall-winter rainfall amounts in 2011-12, 2016-17, and 2017-18.
The report, written by hydrogeologist and sheep counter John Peterson, shows rainfall throughout the Park to be about average for the 2011-2012 season, wetter than average for 2016-17 (preceding our Super Bloom in the Spring), and drier than average for the 2017-18 season. He reported that higher evapo-transpiration rates appear to occur during drier periods, and TDS values tracked that trend. “These three (seasons) provide an excellent range of rainfall patterns in order to evaluate if meteorological conditions impact water quality in the Park.”
Samples were taken by the sheep counters and returned for TDS analysis. “The three-year TDS range in the Park showed a low of 370 TDS at Cougar Canyon in 2017 to a high of 4,070 at Rattlesnake Springs in 2012,” Peterson reported.
For reference, distilled water contains 0 micrograms TDS per liter (MG/L), while seawater contains about 32,000 MG/L of TDS. The BWD supplies drinking water for public consumption in the 250-600 MG/L TDS range.
Peterson suggests that while Bighorn Sheep should be able to tolerate TDS levels far above the highest levels recorded in the Park, he recommends that water should not be collected and filtered for human consumption at selected Park/canyon locations where TDS is shown to be above State maximums for both Recommended and Allowable levels.