Construction of the East Fork Reservoir Siphon

January 22, 2009
Story by District Conservationist, Bret Bledsoe
Photos by Public Affairs, Ivy Allen

In 1938, the East Fork of Rock Creek was dammed and a transfer pipeline (siphon) was constructed to move the impounded water to the Flint Creek drainage. Historically, Flint Creek was a seasonal water source, going dry during the latter part of August. Long-time residents tell stories of using dynamite to blast holes in the streambed of Flint Creek to collect enough water for livestock. Water from the siphon was first used in the Flint Creek Valley during 1939 growing season.

“The siphon is the lifeblood of the Phillipsburg valley. It provides water for the livestock, pastures, irrigation systems, fish, wildlife, recreation, and most of the valley’s ranches,” said Bret Bledsoe, NRCS district conservationist in Philipsburg, “It was the partnership effort between NRCS, U.S. Forest Service, Montana Department of Natural Resources and Conservation, and MT Fish Wildlife and Parks that made this large project a true collaborative success.”

During the last 18 years, NRCS has cost-shared over 40 irrigation systems in the Flint Creek valley. Without water from East Fork Reservoir, irrigation would be limited or not possible in The Flint Creek Valley. Replacement of the East Fork Siphon started in 2003 with contracts from NRCS, providing financial assistance to over 45 water users; however, the construction work date was not set until August 15, 2008. This year Flint Creek water users agreed to an early shut-off date of the siphon to give the contractor time to replace the siphon before winter.

Construction began with installing a stream crossing to move heavy equipment across Rock Creek and was completed prior to September 1, 2008 to avoid interfering with Bull trout spawning. Once accomplished, work began to remove topsoil and expose the 70-year-old metal pipeline, remove and compress the old pipeline for recycling, and bring in an on-site gravel crusher to make a stable bed for the new pipeline to lie on. Major construction was completed by the end of November 2008 with a successful leak test on the new siphon. Most of the reclamation work was finished before winter set in; the contractor will provide the final touches on the project in spring 2009.

The total cost of the project is 1.3 million dollars. NRCS contributed $750,000 through the Environmental Quality Incentives Program and an additional $155,000 for Technical Service Providers. Additional funding was provided by the Montana Department of Natural Resources and Conservation and by Flint Creek water users.

Advisory Television Media: Video of the project is available in a mini DVC tape format or on a data DVD format. The footage can be previewed at the link below. To request a copy e-mail NRCS at: MT-nrcs-publications@one.usda.gov.

Bret Bledsoe standing next to PVC pipe for new siphon

Stockpile of PVC pipe for new siphon

Overlook of construction site during removal of the old metal siphon pipe