A freshly minted Water Supply Assessment prepared by a consultant said there will be enough water to serve both current and future customers as well as four proposed developments that will require an amendment to the El Dorado County General Plan.
The report said the total normal water-year supply available in 2015 will be 77,900 acre-feet, rising to 107,890 in 2025 and 110,290 in 2035. In both a single dry year and multiple dry years that 2035 total is dialed back to 77,885, leaving a 7,225 surplus due to higher consumption of 70,660 predicted in a dry year.
The 2025-2035 figures include a forecast of increased use of recycled water for landscaping and 30,000 acre-feet from an agreement between the El Dorado County Water Agency and the Sacramento Municipal Utility District. The 1964 agreement allows for 40,000 acre-feet from the White Rock penstock but the district’s recently completed Integrated Water Resources Management Plan forecasts only a demand for 30,000 acre-feet.
The water demand in 2025 is forecast to be 49,937 acre-feet and 67,295 in 2035.
The nearly $127,000 report by Tully & Young Consulting was accepted 4-0 by the El Dorado Irrigation District board Aug. 26. The report and EID staff time were paid 100 percent by the developers, though EID commissioned the study at the request of the county. A state law passed in 2003 provides for this kind of coordination to ensure adequate water supply.
Current customers will use 38,595 acre-feet of water in 2015. Adjusted General Plan Updated land-use will account for 581 acre-feet in 2015, 9,012 acf in 2025 and 25,766 in 2035.
Central El Dorado Hills planned use on a defunct nine-hole golf course is 400 acre-feet in 2025 and 450 in 2035.
Dixon Ranch would use 152 acre-feet in 2015, 517 in 2025 and 482 in 2035.
Lime Rock Valley next to Marble Valley would use 272 acre-feet in 2025 and 573 in 2035.
Marble Valley would use 1,285 acre-feet in 2025 and 2,177 in 2035.
“Most districts use a two-year dry-year period,” said EID General Manager Jim Abercrombie, though he added, “Most plan for three years.”
The most serious drought of the last 138 years was 1975-77, with 15.9 inches and 15.86 inches of rainfall each year. That drought was followed by a year that recorded 47.09 inches of precipitation. The 138-year average is 39.57 inches in Placerville.
EID has a drought management plan that would require water use reductions ranging from 15 percent voluntary to 30 percent mandatory in the third year of a drought.
The Water Supply Assessment report does not require an environmental impact report because it “does not commit the district to a specific course of action,” according to the staff report.
Director George Osborne asked about the 15,000 acre-foot drought back-up in the SMUD reservoir system.
“SMUD agreed to the facility. We have to go get the water,” said General Counsel Tom Cumpston.
“This does not mean that EID is approving these projects,” said Director Bill George.
“Also, it is not a commitment of water. Commitment is when someone applies for a water meter,” Cumpston said.
“Our task is to supply the utility whenever possible,” Osborne said.