Lower Yellowstone Project

The U.S. Bureau of Reclamation’s (Reclamation) Lower Yellowstone Project is 58,000-acre irrigation project located in eastern Montana and western North Dakota. The project is operated and maintained by the Lower Yellowstone Irrigation District Board of Control under contract with Reclamation. The Lower Yellowstone Project includes the Intake Diversion Dam, a screened headworks structure, 71 miles of main canal, 225 miles of laterals and 118 miles of drains, three pumping plants on the Main Canal, four supplemental pumps on the Yellowstone River and one supplemental pump on the Missouri River. 

Diversion Dam Fish Passage Project Overview Diversion Dam Fish Passage Project Overview

Intake Diversion Dam is a rock-filled timber crib structure spanning the entire Yellowstone River about seventy miles upstream from the Yellowstone and Missouri River confluence or eighteen miles downstream from Glendive, Montana. Intake Diversion Dam raises the water elevation within the Yellowstone River so it can be diverted through the screened headworks structure on the north side of the Yellowstone River.  Once water has entered the headworks it flows into the Main Canal and runs along the north side of the Yellowstone River.  The diverted water is used to irrigate crops such as sugar beets, alfalfa, wheat, barely, and rye.

The Project consists of four irrigation districts:

  • Lower Yellowstone Irrigation District #1
  • Lower Yellowstone Irrigation District #2
  • Intake Irrigation District
  • Savage Irrigation District

Pallid Sturgeon Passage and Entrainment Project

Pallid sturgeon (Scaphirhynchus albus) were listed in 1990 as endangered by the U.S. Fish and Wildlife Service under the Endangered Species Act.  Pallid sturgeon are large bodied fish that are well adapted to large, free-flowing, warm-water, turbid rivers with diverse and dynamic physical habitats characteristic of the historical conditions of the Mississippi River basin (i.e., free-flowing with natural hydrologic conditions and temperature regimes).  The pallid sturgeon has a flattened shovel-shaped snout and a long, slender, and completely armored caudal peduncle.  As with other sturgeons, the mouth is toothless, protrusible, and ventrally positioned under the head.  Instead of bone, the skeletal structure is primarily composed of cartilage. 

Since the pallid sturgeon was listed in 1990, Reclamation has been partnering with Montana Fish, Wildlife & Parks, the U.S. Fish and Wildlife Service, and the U.S. Army Corps of Engineers (USACE) to determine effects of the Lower Yellowstone Project on the species.  Through monitoring efforts, two primary issues were identified, 1) entrainment into the Lower Yellowstone Main Canal and 2) lack of passage success over Intake Diversion Dam.  By providing passage at Intake Diversion Dam, approximately 165 river miles of potential spawning and larval drift habitat would become accessible in the Yellowstone River.  Since the early 2000s Reclamation and the USACE, as joint lead agencies, have been working to address passage and entrainment issues associated with the Lower Yellowstone Project.  In addition to protecting pallid sturgeon, Reclamation has also been committed to continuing the viable and effective operation of the Lower Yellowstone Project.

In 2010, Reclamation and USACE authorized construction of a rock ramp and new screened headworks with the completion of an Environmental Assessment and Finding of No Significant Impact.  The screened headworks structure was completed and put into operation during the 2012 irrigation season.  In 2012, during the final design of the rock ramp important new information on the design, constructability, and sustainability of the proposed rock ramp surfaced along with new information regarding pallid sturgeon movement which led to a reevaluation of fish passage options.

Rockramp and new screened headworks. Rockramp and new screened headworks.

In 2013, due to significant design concerns with the rock ramp, Reclamation and USACE conducted a replanning effort to examine new and previously considered fish passage alternatives.  Following this effort, Reclamation and the USACE identified a bypass channel for detailed analysis.  A Supplemental Environmental Assessment and Finding of No Significant Impact selecting the bypass channel for implementation were completed in April of 2015. 

 

Lower Yellowstone Pallid Sturgeon Passage and Entrainment Project

In 2016, USACE and Reclamation completed the Lower Yellowstone Intake Diversion Dam Fish Passage Project Environmental Impact Statement and Record of Decision. In the Record of Decision USACE and Reclamation selected the Bypass Channel Alternative for implementation. The Bypass Channel Alternative includes the construction of an 11,150 ft long bypass channel for pallid sturgeon fish passage, a replacement weir structure for water deliveries to the Lower Yellowstone Project and an Adaptive Management and Monitoring Plan.

Construction on the bypass channel and replacement weir started in June of 2019 and is expected to be completed in the fall of 2022. To date, approximately 90% of the bypass channel and south half of the replacement weir have been completed. In the fall of 2021 and spring of 2022, the north half of the replacement weir and the remaining portions of the bypass channel will be completed. The bypass channel is expected to be available for pallid sturgeon fish passage in the spring of 2023.

Lower Yellowstone Adaptive Management and Monitoring Plan

Reclamation in coordination with the USACE and U.S. Fish and Wildlife Service recently updated the Lower Yellowstone Adaptive Management and Monitoring Plan. This update was critical to better define the adaptive management governance process and to better define how success criteria will be monitored. Consistent with past commitments, Reclamation will be the lead agency on implementing the AMMP. The AMMP has a life of eight years and after those eight years Reclamation will initiate discussions with the U.S. Fish and Wildlife Service on whether major modifications are required or if the plan should continue in its current form. The update AMMP was release in June of 2021 and can be found below.

Past Public Involvement – National Environmental Policy Act (NEPA) Process

2016 - Final Lower Yellowstone Intake Diversion Dam Fish Passage Project Environmental Impact Statement

2015 – Intake Diversion Dam Modification Lower Yellowstone Project - Final Supplement to the 2010 Final Environmental Assessment and Finding of No Significant Impact

2010 – Intake Diversion Dam Modification Lower Yellowstone Project, Montana – Final Environmental Assessment and Finding of No Significant Impact

Endangered Species Act Consultation & Compliance

Reclamation Pallid Sturgeon Monitoring Reports

Last Updated: 6/15/21