Boise’s expanded whitewater park technically opened last July, but the city closed the centerpiece wave formation to wave riding action for nearly a year-and-a-half due to safety concerns.
The over $11 million expansion of the J.A. Kathryn Albertson Family Foundation Boise Whitewater Park is downstream from the original whitewater park near Esther Simplot Park, and features three artificial waves, a terraced seating area, and improvements to the river accessibility. The park opened to much fanfare from expert surfers and kayakers last summer, but early testing of the first, and largest, wave feature of the newly expanded park found “instability.”
Boise Parks and Recreation Director Doug Holloway presented an update on the park to City Council on Tuesday, outlining adjustments to the park set to be completed in December and January to remedy the situation.
“The wave had a tendency to collapse upon usage and create a very dangerous situation,” Holloway said. “What we have asked the contractor to do is work on a model that would create a safe wave moving forward and basically the contractor has spent in the past year working with the design engineering and a lot of other factors going into that safe wave.”
The work to adjust the wave is factored into the original budget for the project and will not cost taxpayers any extra funds, Holloway said.
‘Not as high energy’
The second and third wave in the project are small and friendly to beginners, but the first wave is one of the most powerful synthetic waves in the United States. In the original plan, the water flowed through the wave at 900 cubic feet per second and formed into a continuous wave by a machine instead of rocks built into the riverbed.
After typical water flows returned to the Boise River in the spring, crews from engineering firm McMillen James Associates planned to work on studying the wave and making tweaks to the design to make it safer. But, when COVID-19 stopped all in-person work, the company worked with a lab from the Czech Republic specializing in modeling synthetic waves to alter the design.
Mort McMillen, an engineer who has worked on both whitewater park projects from the beginning, said the planned changes include flattening the wave ramp, reconfiguring some of the blocks under the water forming the wave and lowering the speed of the water through the wave shaper. The new wave will run between 400 and 700 cubic feet per second.
He said the hope for the tweaked wave is a stable, safe park able to run continuously all day without interruptions or a need for staff to constantly change the settings.
“It’s not as high energy, but it’s easier to control,” he said. “We found out what our problems are with the physical model and addressed those with slight adjustments in the field.”