A diversion that’s worth a dam: $21 million construction project coming to Barber Park
Construction is starting on a $20.9 million replacement of the Ridenbaugh Canal Diversion Dam, which brings water to the second-largest irrigation conveyance system in the Treasure Valley.
The dam, built in the 1930s, is close to the end of its “usable life,” according to an email from the Idaho Department of Water Resources. The dam’s concrete footings stretch across the Boise River near Barber Park, topped with wooden planks. Workers need to install boards into the dam manually to divert water, which is “dangerous and treacherous and inconvenient and challenging,” according to Roland Springer, acting regional director of the U.S. Bureau of Reclamation.
The new structure will have automatic iron gates that workers can can raise and lower.
“We’re ensuring it continues to serve for the next 100 years,” Springer said Tuesday at an outdoor news conference as rain rippled the area where water runs into the canal.
The Ridenbaugh Canal system began in 1865, though it was not completed until later, according to the Idaho State Historical Society. The canal and its headworks were originally built in 1878 and redone in 1936, according to the irrigation district.
The 42-mile long canal runs from Boise through Nampa and diverts 240 million gallons a day, according to the district. The canal irrigates more than 108 square miles, the district said. Water goes to Boise, Meridian, Kuna, Nampa and Caldwell, as well as other irrigation districts, according to the email from the Idaho Department of Water Resources.
Construction workers will toil over the next two winters, with an estimated finish date of the beginning of 2027, according to Greg Curtis, capital projects manager with the Nampa & Meridian Irrigation District, which operates the canal.
The irrigation district will contribute about a quarter of the cost, Curtis said. The rest will be made up by $10.4 million from the Idaho Water Resource Board and $4.7 million from a Bureau of Reclamation grant.
Cost has been an important issue for the district with this project. Price pressures are coming nationally and locally. For example, Curtis said Tuesday that the group didn’t see tariffs coming. President Donald Trump has imposed tariffs on various goods throughout his second term so far.
It’s not just national either. The local economy is also facing rising costs, with large swaths of workers and materials going towards Micron’s expansion and Meta’s data center in Kuna, Curtis said. Micron has been building a $15 billion fab (industry shorthand for a semiconductor fabrication factory) and has plans for another plant. Meta’s 1-million-square-foot data center (costing $800 million) hit “peak construction” in April, according to previous Statesman reporting.
Any delays to the project would be costly, Curtis told the Statesman.
