The state groundwater monitoring program ranked the Yolo sub-basin one of the highest-priority basins in the state. Covering about a third of the county, the Yolo basin supports a growing population of about 200,000 people, and more than half of its acreage per square mile is farmland.
Other factors in its priority ranking included the number of wells per square mile. The county has issued a decade-high number of well permits in the 2013-14 fiscal year, likely due to the drought.
The Sacramento River hydraulic region contains 88 basins — of those, 23 are ranked high and medium priorities, meaning significant population and agriculture dependence. Throughout the region, about 27 percent of the water used in an average year comes from these natural underground reservoirs; however, during drought years like this one, dependence on ground water increases significantly and can strain water availability.
As ground water elevation levels drop, irrigation and drinking wells have to dig deeper.
While these reservoirs naturally recharge during wet years, particularly dry areas like the San Joaquin Valley have seen their water levels sink deeper and deeper. According to Max Stevenson of the Yolo County Flood Control and Water Conservation District, Yolo County’s as a whole have stayed relatively stable.
The California Statewide Groundwater Elevation Monitoring program is part of the state’s push to better track California’s water resources. With about 3,000 water public and private agencies in the state — no one is quite sure how many there actually are — the program aims to centralize a majority of groundwater elevation data.
— Reach Elizabeth Case at [email protected] or 530-747-8052. Follow her on Twitter at @elizabeth_case