LAKE TULLOCH ALLIANCE - August 25th Tri Dam Announcement

An update on Stanislaus River water management operations
From the South San Joaquin and Oakdale Irrigation Districts

On Aug. 7, 2015, the Tri-Dam Project issued an advisory notice of the upcoming need to draw down Tulloch Reservoir as part of a multi-agency plan to lower water temperatures in the Stanislaus River for rainbow trout, which are protected under the federal Endangered Species Act.

The notification to land owners around the lake specified that lowering the reservoir level could begin as early as Aug. 23 and would be coordinated with additional water releases upriver at New Melones Reservoir managed by the U.S. Bureau of Reclamation.

Today, the Bureau of Reclamation issued its updated management plan for the river and the reservoirs. Here are the key points:

New Melones began the day at an elevation of 808.94 feet. The reservoir is falling about 5-8 inches per day.

When New Melones gets to 808 feet, the Bureau of Reclamation will be able to “partially” open its low level (cold water) outlet at the bottom of the dam and begin “blending” this colder water with the warm water currently being released from its upper level outlet. The upper level outlet will be cut back 250 cubic feet per second and a low level outlet will be opened to 250 cubic feet per second to maintain flow releases out of New Melones.
Flows going down the river as well as flows into and out of Tulloch Reservoir will not change. No significant drop in Tulloch’s elevation is anticipated this week as we maintain the current elevation range of 506.5 feet to 509.5 feet.
Cool evening temperatures and the breezes we’ve been experiencing are lowering water temperatures, which is a good thing. The forecast is more of the same for the remainder of this week. We anticipate the flow situation outlined above to remain in place through this week. The next review will occur Monday, Aug. 31.

We appreciate the Bureau of Reclamation’s efforts in coordinating and adjusting its river operations to reduce impacts to all river users during this challenging period.

Tulloch has a regular draw down protocol that occurs every year that is done in accordance with Federal Energy Regulatory Commission licensing regulations that apply to the reservoir. Normally, the draw down begins in mid-September. This year, because of drought-related temperature issues in the river related to fish, the draw down may begin earlier. The same thing occurred in the 1977 drought.

The draw down may possibly take the lake to 480 feet -- the same level as the winter of 2012-13, the last time Tulloch was lowered to test its spill gates. It will not go lower.

Tulloch will refill on the same schedule it always does, beginning mid-March 2016. It is imperative to refill Tulloch because the reservoir serves to provide back pressure on generators at New Melones so they can operate and produce electricity.
The Oakdale and South San Joaquin Irrigation Districts own Tulloch Dam and the powerhouse and have the right to the water stored in the reservoir. They also own Beardsley and Donnells reservoirs further up the Stanislaus River in Tuolumne County. The two districts formed the Tri-Dam Project to manage these assets.

For updates and information on the water level at Tulloch Reservoir, go to www.tridamproject.com. For more about water management of the Stanislaus River, go to www.savethestan.org or www.facebook.com/SavetheStanNow.