On - Vineyard Recharge

Irrigation-For-Recharge Practices in Santa Rosa Vineyards Lead to In Lieu Recharge, Increased Groundwater and Root Zone Moisture Levels, and Potential Increased Stream Flows, 2016 - Ongoing

Collaborating Organizations Funding Organizations

Tetra Tech, UC Davis

Project Summary

We tested Irrigation-For-Recharge (IFR) on a mature vineyard along Mark West Creek to determine potential groundwater and agronomic benefits. The Santa Rosa Plain is designated a medium priority basin under California’s Sustainable Groundwater Act (SGMA), particularly with regards to surface water and groundwater connectivity, and the declining groundwater levels in the intermediate to deep aquifer zones, 200-800 ft below ground surface. Area wine growers began investigating improved farming practices to reduce groundwater demand and facilitate regional compliance with SGMA.

For this demonstration project, we applied captured surface water routinely to a 20.93-acre field, using sprinklers typically used for frost protection, during early Spring. For this field and two control fields, we collected data (i.e. frost control, irrigation, recharge, precipitation, ET) to calculate water budgets and estimate percolation toward the water table. We monitored changes in root zone soil moisture and conductivity in IFR and control fields. We also tracked surface water and groundwater elevation levels and conductivity throughout the ranch.

The study, implemented within Windsor, California, tests the ability of an on- farm sprinkler system, to raise water table levels prior to, throughout, and beyond irrigation season. The project evaluates the best management practices for optimal recharge and harvest. Mark West Creek runs adjacent to the winery allowing us to see the effects of the recharge on nearby surface water levels. The results of this project will be available for farmers who would like to adopt the Best Management Practices suggested.

IFR is cost effective, sustainable, and easy to implement. Surface water recharge prior to summer irrigation is an option for farmers seeking to recharge the aquifer and reduce dry season water use. An elevated water table may increase base flows in nearby surface water, preventing surface water depletion to groundwater. Over a grander scale, higher groundwater levels prevent surface water loss, enabling stream connectivity throughout the season. If the water table is raised into the root zone, less summer irrigation is necessary due to higher root zone moisture levels. Furthermore, salts in the root zone may be flushed out, improving water quality.

Surface Water from Mark West Creek toppling into vineyards during rain event.

Vineyards blooming.

Staff Gauge Set up at Mark West Creek.