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Supporting sustainable food, power, and water for over 100 years

In 1908, a hydroelectric plant was built on the north end of Potter Valley, replacing a coal-fired plant to power the city of Ukiah. Today, roughly 3% of the Eel River watershed is diverted to the Russian River to run the turbines.

Potter Valley Irrigation District provides agricultural water for Potter Valley, in Mendocino County, California, using a portion of the water diverted through the power plant. Potter Valley's family farms produce wine grapes, pears, grass-fed cattle, sheep and other agricultural products valued at over $34 million.

cattle crossingThe Great Green Pumpkin
Picking Blackberries in Potter Valley, July 2015
Picking blackberries in Potter Valley, July 2015

Potter Valley Irrigation District water status update

January 16, 2015

Dear Potter Valley,

We have made it through one of the driest water years on record. We need to applaud the combined effort of farmers, ranchers, Potter Valley Irrigation District Board and staff, PG&E, and a multitude of environmental and fisheries resource agencies. Their management of the limited water resource stored in Lake Pillsbury by Scott Dam was truly commendable. The water supply for farming, fisheries protection and infrastructure concerns were all addressed during the low water conditions at the dam.

The long irrigation season in 2015 following the previous two years of drought did take a toll on farms and ranches in Potter Valley. Some farmers chose to fallow some of their pasture and irrigated only what was necessary to survive. The long rotation interval between irrigations made for smaller yields. Ranchers had to move livestock off range land to pasture for lack of feed much earlier than normal. Vineyards kept vines alive with their drip irrigation but didn't achieve a normal root zone depth irrigation. The extended irrigation interval was a factor here as well. PVID is attempting to assess the losses that have occurred due to a multitude of drought related factors. We will publish those findings at a later date.

Looks like we might actually have a winter this year! Potter Valley has received 22" of rain and a snow pack is building within the Lake Pillsbury drainage as of 1-5-16. Lake Pillsbury is as full as it can get with the top gates open on Scott Dam. The top gates are historically closed on the first of April each year. These gates can be closed early in March if we don't receive sufficient rain or snow pack. The State Division of Safety of Dams, along with PG&E and the projected long range weather forecasting from NOAA, will make that determination. It is this snow pack that helps to keep the lake level higher going into the summer and ensure water is also available to supplement flows during drought conditions to improve fisheries habitat in the Eel River when needed. Without this stored water the upper main stem of the Eel River would have been but a trickle for many months in 2015. Let's hope this winter puts down the snow we need to bring the PV Project flows for the East Branch Russian River back to normal in 2016.

The PG&E Potter Valley Project is currently shut down for the replacement of a large section of the wooden pipeline connected to the two steel penstocks that deliver water to the generators. They are bypassing only 22 CFS as allowed by a FERC approved variance. The required minimums to the East Branch Russian River and PVID will remain in place until project completion which is projected to be prior to March 15, 2016. Unfortunately, this year, with Lake Pillsbury storage level being above the target storage curve due to the early rainfall, the PV Project could be diverting up to their maximum rate of 270 CFS for power generation. We must remember though, maintaining the infrastructure of the Potter Valley Project will help insure the continued flow of water for beneficial use in Mendocino, Sonoma, and Marin Counties. This includes environmental needs as well.

Just a reminder, please maintain a record of each irrigation. A calendar works well for logging the start date & time and the stop date & time.

Steven Elliott, Superintendent
Potter Valley Irrigation District

New Documents

Check out our new interactive map of the Eel River watershed. It includes major and minor watershed boundaries, USGS stream gauges, popups with pictures and data at points of interest, and major peaks overlaid on a satellite image.

The PVID Documents & Data page collects scientific papers, government reports, regulatory documents, and other relevant data and information for the Eel River and Russian River systems. In some cases, we have scanned or acquired papers that were not previously available in electronic format to make them available here, such as Kubicek, P.F. 1977., which is a key study of Eel River summer temperatures.

Potter Valley Project 2012 Block Water Releases & Guidelines (12 MB PDF) is from a July 30, 2012 presentation to the Eel-Russian River Commission Meeting by Dick Butler and Jeffery Jahn of NMFS. This is an excellent discussion of the use of Lake Pillsbury block water and considerations used to determine whether proposed water releases are appropriate and beneficial to fish.

Potter Valley Project Block Water Request 2014 - NMFS/CDFW press release discussing their 2014 block water request of 2,085 acre-feet for the purpose of lowering and monitoring the water temperature from Lake Pillsbury to Outlet Creek to protect juvenile steelhead from August 15 through October 11. The release will be closely monitored to determine its effectiveness and also to inform future models of the system.

C. Hypotheses and Effectiveness Monitoring

This blockwater release will test the following hypotheses:

  1. Increased releases from Lake Pillsbury through the Scott Dam needle valve will increase the extent of the optimal coldwater rearing zone (≤ 20°C) between Scott and Cape Horn dams.
  2. Increased releases from Lake Pillsbury through the Scott Dam needle valve will decrease water temperature and increase habitat availability (using flow as indicator) downstream of Cape Horn Dam to Tomki Creek.
  3. Sufficient reservoir storage will sustain a coldwater pool that effectively maintains favorable steelhead temperature-dependent interaction conditions between Scott and Cape Horn dams.

The following data will be gathered to test these hypotheses:

The latest Russian River frost water regulation decision (2.7 MB PDF) was reached on 9/26/12. The State Water Resources Control Board's Section 862 frost water regulation on the Russian River was judged an improper exercise of the Board's authority. The Findings of Fact contains a substantial narrative discussing frost protection in the Russian River watershed and the use of water for this purpose. While these frost water regulations excluded Potter Valley, it is worth reading the narrative to get a better understanding of water issues on the Russian River system.

We've created a new interactive graph of Van Arsdale Fish Counts showing all historical data from VAFS starting in 1933. You can also download the raw data in CSV form, if you wish. The graph makes it easy to compare the counts of the different species and to see how counts have changed over the years.

potter valley panorama