• Sustainable Conservation

This technical memorandum documents the development and early implementation of an agricultural groundwater recharge program in Yolo County. Prepared by Sustainable Conservation in partnership with the Yolo County Flood Control & Water Conservation District and the Yolo Subbasin Groundwater Agency, the memo outlines strategies for expanding on-farm recharge, engaging growers, and prioritizing recharge opportunities to support Groundwater Sustainability Plan (GSP) implementation.

A key component of the effort was the creation of a recharge prioritization mapping tool that integrates factors such as conveyance access, willing landowners, reported dry wells, subsidence-prone areas, groundwater-dependent ecosystems, and community water system service areas. The memo describes the methodology used to identify and rank potential recharge locations and discusses how these tools can support strategic program planning and grower outreach.

The document also summarizes lessons learned from Yolo County’s 2025–26 recharge season, during which more than 4,000 acres of farmland participated and over 3,800 acre-feet of water were applied for recharge. Findings highlight the importance of combining targeted site selection with voluntary grower participation, reveal unexpected recharge opportunities on rice lands, and explore innovative approaches such as winter “pre-irrigation” to reduce groundwater demand later in the growing season.

The memorandum concludes with recommendations for advancing groundwater recharge programs, including development of a full Groundwater Recharge Assessment Tool (GRAT), continued grower outreach and incentives, enhanced groundwater modeling, water quality safeguards, and farmer-to-farmer learning networks. The report offers valuable guidance for GSAs, irrigation districts, and practitioners seeking to scale managed aquifer recharge and on-farm recharge programs throughout California.

• Hydrology Observation and Prediction
• Land Use Planning and Management
• Recharge and Extraction Methods and Measurement
• Soils, Geology, and Aquifer Characterization