Welcome to the Tri-Dam Project

Tri-Dam Project is a partnership between the Oakdale Irrigation District and the South San Joaquin Irrigation District. Together they developed, operate and maintain the Beardsley, Donnells and Tulloch projects including the dams, tunnels, penstocks, power houses, communications systems, and general offices. These facilities are located on the Middle Fork of the Stanislaus River in Tuolumne County, California.

The "Upper Works" include Donnells and Beardsley dams, reservoirs, power houses and appurtenant facilities. The "Lower Works" refer to the Tulloch development below Jamestown reaching into both Calaveras and Tuolumne Counties.

Tri-Dam Project is governed by a joint board of directors composed of the five member boards of the two Districts. The day to day activities of Tri-Dam Project and Tri-Dam Power Authority are managed by a General Manager who reports to the board. The administrative offices of Tri-Dam Project are located in Strawberry, California.

Dam Good Photos Beardsley ReservoirDonnells ReservoirTulloch Reservoir

Special Notes:

The following documents concern upcoming recreation improvements at Beardsley Reservoir:

Beardsley day use and boat launch closed beginning Tuesday, September 3, 2013.

Notice of Current Construction and Closure Schedule for Beardsley Reservoir.

Read this letter from Tri-Dam Project regarding the Tulloch Project Article 409 Reservoir Recreation Plan.

The Tulloch Reservoir Drawdown Schedule for 2013/2014 is now available on the Tulloch page.

Save the STAN Please visit Save the STAN, a public education effort of South San Joaquin and Oakdale Irrigation Districts.

Data for April 21
Click below for historical data

Elevation (feet above sea level)
3,277.40 Beardsley
4,846.89 Donnells
504.30 Tulloch
Storage (acre feet)
27,164 Beardsley
37,589 Donnells
60,097 Tulloch
Outflow (cubic feet/sec)
136 Beardsley
97 Donnells
2,507 Tulloch
Road Conditions
Current road conditions to Beardsley and Donnells Reservoirs can be found on their respective pages.