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:

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 Refill Schedule for spring 2013 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 June 18
Click below for historical data

Elevation (feet above sea level)
3,343.74 Beardsley
4,906.19 Donnells
509.57 Tulloch
Storage (acre feet)
62,542 Beardsley
60,234 Donnells
66,432 Tulloch
Outflow (cubic feet/sec)
Road Conditions
Current road conditions to Beardsley and Donnells Reservoirs can be found on their respective pages.