California passed the Water Conservation Act of 2009 (SBx7-7) to encourage water conservation practices across the State’s agricultural water supplies; among other mandates, it required suppliers serving more than 25,000 acres were required to develop an agricultural water management plan (AWMP). Davids Engineering (DE) prepared an AWMP for the Yuba Water Agency, which diverts water from the Yuba River for delivery to eight smaller agricultural water suppliers, known as member units. The plan includes a description of the regional setting and water supplies; water management activities, objectives, and opportunities; potential effects, impacts, and mitigation strategies for climate change; both regional and detailed water budgets; implemented and planned efficient water management practices; and recommendations for improvement and modernization projects, additional data collection, additional studies and planning, and partnerships to improve water management in the region.
The Yuba Water Agency is a leader in water management in the region, and beyond striving for the long term reliability, quality, and affordability in water supplies for the member units, it also plays a role in flood protection, fisheries enhancement, development and sale of hydroelectric power, and recreation. The area included in the AWMP is located within Yuba County on the east side of the Sacramento Valley in northern California; in total the eight member units comprise roughly 80,000 acres. The eight member units are Brophy Water District, Browns Valley Irrigation District, Cordua Irrigation District, Dry Creek Mutual Water Company, Hallwood Irrigation Company, Ramirez Water District, South Yuba Water District, and Wheatland Water District. The primary crop grown in the region is rice, and additional crops include pasture, walnuts, and prunes. A key aspect of YWA’s water management highlighted in the AWMP is conjunctive management of surface water and groundwater supplies. Through providing available surface water from the YWA to member units for irrigation, YWA was able to reverse potentially serious groundwater overdraft in the South Yuba groundwater basin and allow declining groundwater levels to recover. YWA continues to actively facilitate conjunctive use of groundwater, particularly in times of limited surface water availability. The AWMP allows YWA to evaluate its ongoing water management practices and identify opportunities for improvement to meet local, regional, and statewide water management objectives.
In addition to development of the AWMP, Davids Engineering has provided technical assistance to YWA and the member units through the implementation of a delivery measurement program, identifying, designing, and implementing system improvement and modernization projects, and preparing and calculating water balances (including development of an IWFM Demand Calculator (IDC) model to quantify water balance inputs). In 2015 and 2020, Davids Engineering updated the AWMP for YWA. Davids Engineering continues to be actively involved in advancing water management in the region.