Forsyth, MT: Cartersville Dam

Section 206, Water Resources Development Act of 1996

Published April 21, 2015

Location and Description: Cartersville Dam is a six-foot high, 800-foot long irrigation diversion dam/weir spanning the Yellowstone River at Forsyth, Montana. The dam is approximately 235 miles upstream from the mouth of the Yellowstone River and 165 miles upstream from the Intake Diversion Dam. The dam was originally constructed during the 1930s and consists of a rock and willow structure capped in concrete. The dam provides head for gravity diversion to the Cartersville Irrigation District. 

Problem and Need: Cartersville Dam is a private irrigation dam owned and operated by the Cartersville Irrigation District. The dam has been documented as a barrier to upstream fish migration of Yellowstone River native warm water fish (including shovelnose sturgeon, blue sucker, sauger, and burbot). The dam itself is also a safety concern for recreational fishermen and boaters due to uneven crest and turbulence. The headgate structure, which diverts water into the canal, is currently unscreened, and there is concern that native fish may be unintentionally entrained into the canal. The Cartersville Dam has suffered some deterioration due to age, high flow, and ice events. A multi-agency collaborative effort has been initiated to work with the irrigation district to pursue fish passage and potential screening of the canal for ecosystem restoration purposes. 

Activities for 2015: Initiate the feasibility study by preparing the Federal Interest Determination and negotiate the Project Management Plan. Execute the Feasibility Cost Share Agreement with the sponsor. 

Issues and Other Information: Cartersville Dam is the second diversion dam upstream from the mouth of the Yellowstone River, approximately 165 river miles above Intake Diversion Dam. Other diversion dams upstream from Cartersville are somewhat smaller and are believed to be only partial barriers to fish migration. Restoring fish passage at Cartersville Dam would complement ongoing rehabilitation work at Intake Dam to provide unimpeded passage from the Bighorn River confluence to the mouth, a total distance of over 300 miles.