LAKE COUNTY ? Recent rain has helped lake and ground water levels, according to officials, but likely not enough for Yolo County Flood Control and Water Conservation District to draw surface water from Clear Lake this year.
The Yolo district has the right to use approximately 150,000 acre-feet of Clear Lake”s water per year. According to Tim O”Halloran, the district”s general manager, just less than 21,000 acre-feet are available now. Yolo uses the water from Clear Lake and the Indian Valley Reservoir to irrigate its farmland, but O”Halloran said limited surface water in both water bodies makes a dam release unlikely.
“We are not anticipating an irrigation release because there is not enough water to make it worthwhile. I would say there is less than a 50-percent chance,” O”Halloran said.
Clear Lake”s water level measured 3.97 on the Rumsey scale on Monday morning, according to Lake County Water Resources Engineer Tom Smythe. The Rumsey scale gauges the lake level relative to the Grigsby Riffle, a rock ledge that crosses Cache Creek at a narrow point approximately one and a half miles from Clear Lake that limits the amount of water that can flow through it.
Clear Lake must measure 3.22 on the Rumsey scale on May 1 of each year for Yolo to release water for irrigation. Even though the lake”s water level is high enough to allow Yolo to release water, there are currently less than 43,000 acre-feet available in the Indian Valley Reservoir. Combined with Clear Lake”s available surface water, the district would have less than 65,000 acre-feet available.
“We need to get to about 80,000 to 90,000 before we would go for a release,” O”Halloran said.
Anything less would not last until the end of Yolo”s irrigation season in October, and would be better saved for next year. In an ideal irrigation season, the district would use a combination of 250,000 acre-feet from both water sources, according to O”Halloran.
O”Halloran said Yolo will likely have to draw on its groundwater wells this year for irrigation.
The Lake County Board of Supervisors adopted a measure asking water purveyors to conserve water in late February.
Smythe reported at the time that water levels at 85 wells throughout the county were below average. He said groundwater levels will be measured again throughout the county in April, and he will make recommendations about whether to continue recommending water conservation based on rainfall at the time.
Contact Tiffany Revelle at trevelle@record-bee.com, or call her at directly at 263-5636, ext. 37.
