Demand Reduction Strategies Project - Updated May 2026
This project developed and piloted demand reduction strategies to support groundwater sustainability in the Vina Subbasin. The project included two interrelated pilot programs: the Extend Orchard Replacement (EOR) Pilot Program and the Precision Irrigation (PI) Pilot Program.
Working in partnership with the Agricultural Groundwater Users of Butte County (AGUBC) and technical consultant Land IQ, the Vina GSA engaged growers across diverse soil types and geographic areas within the Vina Subbasin.
Both pilot programs were completed in March 2026 and successfully achieved their core objectives to quantify the water-savings potential from demand-reduction strategies and develop practical tools and recommendations for subbasin-wide implementation.
Key Accomplishments
Extend Orchard Replacement (EOR) Pilot Program
The EOR program examined how much water could be saved if growers waited an extra year or two before replanting old almond and walnut orchards (which are usually replaced every 25 to 35 years). The study explored different ways to manage this resting land to prevent unnecessary water evaporation. This effort helps support the region's goal of reducing groundwater pumping by about 10,000 acre-feet each year.
Key activities included:
- Mapping Orchard Land: Researchers mapped the entire Vina Subbasin, identifying 51,801 acres of active almond and walnut orchards, 2,877 acres of recently removed orchards, and 360 abandoned acres.
- Tracking Grower Practices: The team monitored how growers managed land between orchard plantings. Practices included leaving the dirt bare, planting winter cover crops, or growing short-term crops like wheat, dry beans, and tomatoes.
- Understanding Costs: Economists calculated how much financial support (incentives) growers would need to delay replanting without losing money.
- Water Savings Calculator: The team created an interactive digital tool to help local water managers predict how much water could be saved depending on how many growers participate and what they plant on their resting land.
Key Findings
Delaying replanting saves between 0.91 and 2.62 acre-feet of water per acre each year, depending on what is growing on the land. However, to make this affordable for growers, the economic study found that farmers might need financial incentives of up to $790 per acre per year.
Precision Irrigation (PI) Pilot Program
The PI program focused on helping growers water their crops more efficiently. The goal was to cut down on wasted water that doesn't actually help the crops grow—such as water that evaporates into the air, runs off the field, sinks too deep for roots to reach, or is applied unevenly across a field.
Key activities included:
- Surveying Irrigation Methods: The team examined the different irrigation systems and methods local growers use.
- Monitoring Pilot Orchards: Researchers compared the water applied by growers with the water consumed by the crops and the final harvest yields across 26 test orchards during the 2025 season.
- Evaluating Decision-Making: The study found that most growers are already highly technical. About 75% of the pilot growers use two or more scientific tools to decide when to water.
Key Findings
Medium- and large-scale almond and walnut farms in the area are already very efficient with their water use, meaning there isn't much room to save more water by simply upgrading their irrigation technology.
However, the study identified two specific practices that could help save water:
- Pressure Chambers in Walnuts: Growers who used a tool called a pressure chamber to gauge how thirsty their walnut trees were applied about 22% less water. If 20% more walnut growers adopted this tool, the region could save about 1,950 acre-feet of groundwater every year.
- Watering at Night: Shifting irrigation from midday to nighttime reduces evaporation losses, saving about 0.35 acre-feet of water per acre. Plus, watering at night saves growers about $65 per acre on their electricity bills.
Feasibility Studies
These are feasibility studies, the outcomes of which are documented in these reports. The results from these analyses will be used to inform the scope of work, next stages, and/or feasibility of future projects identified in the GSP. Public comment on this or other SGM grant-funded studies is welcome and will be consolidated and provided to the SHAC and Board as part of the development of GSP Projects and Management Actions or grant applications. Please submit written comments via the form linked below.
- Precision Irrigation Pilot Study Final Report - 1.pdf
- Precision Irrigation Pilot Study Final Report - 2.pdf
- Extend Orchard Replacement Pilot Study Final Report - 1.pdf
- Extend Orchard Replacement Pilot Study Final Report - 2.pdf
Consultant: Geosyntec/LandIQ
Project Partner: Agricultural Groundwater Users of Butte County
Total Project Budget: $1,600,000
PROJECT CONTRACTS:
VX0003_Geosyntec (Demand Reduct & Lindo Channel).pdfVX0001_AGUBC (Demand Reduct & Surface Water Supply).pdf