May 8, 2025

Project Construction Finishing Touches Include Technical Work and Testing

As major construction components, such as the valve house structure, main dam and tunnel take shape and look mostly complete from the outside, there is still a lot of work that must be done before it’s ready to go. The detailed, high-tech work occurs at the tail end of the reservoir construction project and includes tasks like installing fiber optic cables and local control panels, as well as finishing touches such as lighting and HVAC. 

Chimney Hollow will be operated remotely from Northern Water’s master control center, so a critical task occurring now is tying into that system, as well as integrating with the U.S. Bureau of Reclamation control systems.  

“We have 16 separate commissioning plans, and we go through each piece of infrastructure. We verify that everything is completed to the plans and specifications. Then we go through and test it to make sure it’s doing everything it’s supposed to do,” said Northern Water Principal Project Manager Joe Donnelly. 

Testing includes dry testing, leakage testing and wet testing all of the valves on site. Dry testing consists of opening and closing each valve completely three times and measuring the electric current and timing of every valve to make sure it works the exact same as it did in the factory. All dry testing is complete, and all valves passed.  

Leakage testing is underway, which consists of filling the pipelines with water, pressure testing all pipes and making sure they hold water. Following this process, crews will being wet testing, which is the same process as dry testing.  

Once Barnard has completed all of its testing, Northern Water will take control of the system and begin filling this summer.  

“Our plan is to fill the reservoir slowly and cautiously; and monitor all the instrumentation and equipment on the dam as the water comes up to make sure that everything is performing as we expect it to,” said Donnelly.