Your Fees at Work
Through the Vineyard Waste Discharge Requirements group monitoring effort, Napa County Farm Bureau helps facilitate a shared approach that reduces the cost of required monitoring for participating growers. Those fees support studies like these—funding streambed monitoring, BMP effectiveness monitoring, data analysis, and reporting that provide the Water Board with real, local data on conditions in the Napa River and Sonoma Creek watersheds.
The findings demonstrate why this work matters: more than 90% of each type of road sediment BMP studied was found to be effective, providing measurable evidence that commonly implemented agricultural practices are successfully reducing sediment delivery to streams. By helping growers share the cost of this required work, Farm Bureau is not only making compliance more affordable—we’re helping ensure that future regulatory conversations are informed by credible, locally collected data that reflects the work Napa agriculture is already doing on the ground.
From Compliance to Results: Monitoring Napa’s Streams and Vineyard Road Treatments
Spring Marks the Start of Monitoring Stream Beds and Road Treatments for the Vineyard General Permit
The Vineyard General Permit, adopted by the California Water Board in 2017, requires monitoring to evaluate streambed conditions and the effectiveness of treatments that are prescribed to help vineyards comply with the Permit. A Monitoring Report is due to the Water Board in early 2024.
Napa County and Sonoma County Farm Bureaus worked with Napa and Sonoma Resource Conservation Districts (RCDs) and the Water Board to develop a Monitoring Plan in 2021. The Farm Bureaus then hired Napa RCD to spearhead the monitoring.
The monitoring entails two different studies, both of which began in March of this year. First, Napa RCD and Sonoma Ecology Center are studying the gravel sizes in Napa River and Sonoma Creek to determine if the streambed would support successful spawning of steelhead trout and Chinook salmon. Second, Napa and Sonoma RCDs are studying how sediment-reducing treatments of unpaved roads are performing after enduring use and big storms.
Streambed Monitoring – Studying Size Distribution of Gravels in the Stream
This year, Napa RCD and Sonoma Ecology Center staff will sample gravels from a total of 32 sites in the Napa River, and 20 sites in Sonoma Creek. So far, they have completed site selection based on previous surveys of the river, assessed streambed slope at 32 potential sites, and completed gravel sampling at 13 of 52 sites. Two AmeriCorps Interns provided by the Water Board helped with the sampling. The remainder of the work will be completed at the peak of the dry season (Aug through Oct) when the stream channels are driest. Staff will have all the field and lab data for this year’s sampling by end of year, and Napa RCD will create an interim report to share results. Similar field work will take place next summer, and all the results will be shared in the final report to the Water Board.
Road Treatment Monitoring – Studying the Performance of Sediment-Reducing Treatments
As a first step, Napa and Sonoma RCDs compiled a list of locations at which they have worked with land managers to add road treatments to help improve drainage and reduce erosion. Staff are focusing on assessing the four treatments that are most frequently prescribed as part of the Vineyard Permit: rolling dips, water bars, critical dips, and trash racks. All of the treatments have experienced at least one big storm, and many have experienced multiple big storms since they were installed. Staff obtained permission to visit the properties to assess how the treatments are currently performing. To date, staff have surveyed over 200 treatments, the majority of which are still performing well. Staff are trying to assess treatments across the four main underlying geologies that are found in our watersheds to understand how geology may impact the success of the treatments. Staff are now reviewing the data and determining whether or not more treatments need to be evaluated before submitting a final report. Staff will provide an interim report at the end of the year.