December 2025

The Board of Control (BOC), along with Wood River Valley Irrigation District 45 and the Triangle Irrigation District, has been actively working on a project to repair and remediate the low head dam structure that supports the surface water irrigation needs of the Bellevue Triangle.  The existing dam structure was installed nearly 100 years ago.  It has been repaired multiple times over the years, and has reached the end of its useful life. This project was conceived as part of the 2019 Bellevue Project Area Conceptual Restorations Design Report, which was developed with the collaboration of the Irrigation Districts, Trout Unlimited, Wood River Land Trust, City of Bellevue, The Nature Conservancy, and Idaho Fish and Game. 

The current low head dam blocks upstream fish passage, creates upstream sedimentation and downstream erosion, thereby damaging the river hydrology.  The design of the dam remediation project will stabilize the existing dam structure, provide for fish passage upstream, and improve sediment transport at the diversion dam while improving floodplain conditions and the overall health of the Big Wood River.

The Board of Control hired JUB Engineers, an Idaho-based engineering firm, to assist with the design and permitting of the dam remediation project.  With JUB’s assistance, the BOC applied for project funding through the Bureau of Reclamation WaterSMART program in 2023. The WaterSMART program is intended to help irrigation districts and other entities undertake projects focused on environmental benefits and to help increase the reliability of water resources.  The BOR awarded the project $629,000 in federal funding, based on the following design objectives.

•  Stabilization of Diversion 45 by reinforcing the existing dam, filling the dam with concrete and backfilling the downstream side of the dam
• Installation of a 10 ft wide low flow notch on the dam surface and a roughened rock ramp downstream including installation of several large boulders
• Installation of several large conifer log jam structures that will support a new rock bench along the west river bank below the dam
• Re-vegetation of the area with native plant species

 

The design of the diversion dam remediation project has been completed.

 

In late 2025, the BOC received additional project funding from the Idaho Department of Water Resources Aging Infrastructure grant program in the amount of $999,900. This grant will allow the BOC to move forward with construction of the project in 2026.  Also, a contribution from Project Big Wood will allow the inclusion of a fish screen near the top of the Main Canal to help keep fish from entering into the irrigation laterals downstream.

The BOC intends to solicit bids for construction of the project in January 2026, with the goal of selecting a contractor for award in February.  Environmental permitting for required State and Federal agencies is in process and is expected to be completed in Q1 2026. Construction would then commence in Q3 2026 dependent upon river flow conditions.  The duration of project construction is expected to be not more than 90 days.

The BOC, Irrigation District 45, and Triangle Irrigation District all look forward to seeing this project through to a successful completion.