News

Initial Water to Move into Chimney Hollow Reservoir in April 2026

Northern Water will move approximately 1,500 acre feet of water into Chimney Hollow Reservoir starting mid-April.

Chimney Hollow Reservoir Project Construction Complete

On Dec. 19, just six years after Barnard Construction signed the contract to build the project, the Chimney Hollow Reservoir Project reached substantial completion, which marks a historic milestone.

Final Chimney Hollow Virtual Tour

In the final virtual tour, the project team gives a look at the project nearly complete, as well as an overview on what it's like to demobilize a project of this size.

Chimney Hollow Reservoir logo with valley in background.

Initial Water Delivery into Chimney Hollow Reservoir Delayed

Northern Water and the Chimney Hollow participants have decided to allow more time to gather additional water quality data before initial delivery of water into Chimney Hollow Reservoir.

Chimney Hollow Reservoir Project Wins West Regional Dam Safety Award

The award recognizes projects that make exemplary contributions to the improvement of dam safety in the United States.

Downstream Tunnel Portal Gets Finishing Touches

The final touches on the downstream portal were added at the end of September and include the words “Chimney Hollow 2025” over the entrance.

Uranium Monitoring, Testing and Modeling Continue

We are following a rigorous process, starting with geochemical characterization and scoping studies, to inform mitigation alternatives analysis and ultimately select a final approach.

System to get Water in and Out of Chimney Hollow Nearly Complete

The water conveyance system used for delivering water in and out of Chimney Hollow Reservoir is constructed and nearly complete.

More Than 35,000 Cubic Yards of Concrete Placed at Chimney Hollow

Concrete was used in almost every area of the project, including the plinth, spillway, thrust blocks, valve house, tunnel lining, inlet/outlet, tower, staff gauge and more.