The Roundup -

By Tie Shank 

Lower Yellowstone Diversion Dam Fish Passage


The head gate upstream from the diversion dam at Intake.

What do you get when you combine 225 miles of laterals, 118 miles of drains, the Lower Yellowstone Diversion Dam, Thomas Point Pumping Plant and the main canal? The answer is, The Lower Yellowstone Project. Approximately one-third of the project lands are in western North Dakota and the remaining two-thirds are located in east-central Montana.

According to a recent article written by Gerald 'Jerry' Benock, of the Montana Area Office (MTAO) of the Bureau of Reclamation, "This project is authorized as a single-purpose project to furnish a dependable supply of irrigation water for 53,000 acres of fertile land along the west bank of the Yellowstone River." It delivers water diverted from the river to irrigate roughly 400 farms in North Dakota and Montana.

The Lower Yellowstone Diversion Dam is located approximately 16 miles downstream of Glendive, MT. The original intake diversion project (completed in 1909) remains in place and requires rock to be added regularly to maintain the water level required to divert irrigation water from the river.

Benock's article goes on to say, "Intake Diversion Dam has impeded movements of pallid sturgeon upstream since its construction."

Pallid Sturgeon with its unique dinosaur-like appearance was listed as Endangered under the Endangered Species Act in 1990. The Pallid Sturgeon Recovery Plan was published and put in to action in 1993 by the U.S. Fish and Wildlife Service.

This endangered species was historically present in the Yellowstone River upstream to at least the Confluence with the Tongue River (Brown 1971). However, since 1991 only two adults have been recorded following the historic river flows of 2011. This restriction to upstream migration has created the urgency to provide a safe passage of the Pallid Sturgeon to a spawning habitat located 165 miles upstream on the Yellowstone River.

Additional data has revealed that on average 500,000 fish of 36 species could be entrained annually in the irrigation canal system. The United States Army Corps of Engineers (USACE) is a joint lead agency assisting Reclamation in the design and construction of the Lower Yellowstone Project for the purposes of ecosystem restoration.

The new system must prevent fish loss and entrainment while providing the irrigation water supply to the Lower Yellowstone irrigators. Numerous studies have been conducted and design alternatives looked at for fish passage and entrainment control. In 2009 a design was chosen as the preferred way to achieve both entrainment control and fish passage. The design was completed and operated successfully in 2012.

However, a fish passage was to be provided by expanding the height and length of the rock ramp across the river. The cost of this far exceeded the original gathered information and due to this along with "construction challenges and the lack of confidence in the ability of the system to achieve and maintain long term fish passage without substantial operation and maintenance resources," states Benock, "it was determined that the USACE and Reclamation needed to reconsider previously dropped alternatives for fish passage."

In 2013 the planning study effort began again. The following objectives and Criteria were established:


• Endangered Species Act (ESA) obligations at Lower Yellowstone Irrigation Project for providing passage of juvenile and adult Pallid Sturgeon.

• Maintain long-term viability of the Lower Yellowstone Irrigation Project.


1. Likelihood of ESA Success

2. Water Delivery Reliability

3. Engineering Design/Constructability

4. Acceptability

After many meetings, discussions and careful review of each alternative, the planning team identified the alternative best suited to meet the above objectives and criteria. Reclamation and USACE are currently working on National Environmental Policy Act (NEPA) documents along with design work for the alternative.

The Lower Yellowstone Diversion Dam raises the water level to allow water to flow into the irrigation system. Inset: The pallid sturgeon.

The total federal cost contributed by USACE to assist Reclamation with this effort is approximately $90 million.

Benock states, "The challenge is to provide a fish passage system that meets design criteria developed by a team of fish and hydraulic specialist that will ensure the best opportunity to achieve passage for pallid sturgeon and other fish species and to continue providing irrigation water to the LYIP."

Next week the Reclamation will be posting a link on their website to a 'draft supplement' to the currently posted Final Environmental Assessment. Public meetings will be held in Glendive, MT and in Sidney MT to get feedback on this comprehensive document. Dates of the meetings will also be posted next week on-line at


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