The Yolo County Resource Conservation District undertook a one-year pilot program funded by the  CALFED Water Use Efficiency Program from December 2000 through December 2001.  The District was selected for this pilot program because of its history as an innovator in on-farm water quality improvement techniques, especially those employing native perennial grasses, wetland plants, shrubs, and trees.

Project Goals
The District’s intent in taking on the pilot program was to initiate a more rigorous analysis of the assumed water quality benefits of practices it has long promoted: especially those of tailwater ponds, sediment traps and winter cover cropping. The actual water quality improvements associated with those conservation techniques had never been rigorously quantified. In light of the changing regulatory climate regarding farm runoff water quality, the information gathered may prove particularly useful for informing: (1) regulators of acceptable and measurable water conservation techniques that can be used to meet their goals; and (2) farmers and water managers of proven tools that they can employ in their desire to best manage the water under their control.

The RCD works closely with local farmers and agricultural industry, and is familiar with the stresses and realities of agricultural operations and the families that run them. The RCD is commited to exploring and promoting means of voluntary compliance without direct regulation that allow farmers to continue their business, while properly managing public resources such as air, water, and wildlife.

Positive Outcomes
As part of this Pilot Program, tailwater ponds and sediment traps clearly served their function as devices that entrain sediment, especially when properly designed and maintained. Most of the traps and ponds studied provided some nutrient capture during the initial irrigations as well, although that aspect of their function definitely bears further study.

The winter cover crop study also demonstrated both runoff flow attenuation and sediment concentration reduction. Further study of the degree of success relative to planting date (likely the earlier the better) and cover crop growth stage would help to gauge the most effective application of this technique.

Water use efficiency is compelling for farmers at the very least because of a potential decrease in pumping costs.

While the District considers the information gathered through the Pilot Program to be useful to CALFED in its aim to promote locally-led, on-farm water use efficiency programs, the Pilot Program has also provided an excellent opportunity for the District to refine its on-farm monitoring program and its understanding of potential collaborations for promoting water use efficiency in Yolo County.

A copy of the Final Report from this project, with a detailed discussion of results, is available in the RCD Resource Library folder.