Heavy machines in the Animas River this month are working to replace boulders dislodged last year by sustained high water that blasted the Durango Whitewater Park and caused dangerous conditions for boaters.

Rafting companies stopped running tours through the Durango Whitewater Park for weeks in 2019 to avoid strong recirculating currents that trap boats and kayaks upstream of the park. Mild to Wild stopped running through the park for about four weeks, said Alex Mickel, president and founder.

Last year wasn’t the first time Mild to Wild has stopped running tours around Smelter Mountain, but the features installed might have extended the time tours stayed out of that section of the river, he said.

At the time, the rafting community was outspoken about issues upstream, at least in calls to Durango city officials, said Parks and Recreation Director Cathy Metz. The Durango Parks and Recreation and Utilities departments are collaborating to fund and design the rebuild, she said.

“Last year, we noticed we were having some difficulties with a wave creating somewhat of a low-head dam (at the Whitewater Park),” Metz said. “We wanted to get back into the river to address that.”

This year’s river project, which cost the city about $113,000, is one of at least three in the past four years, said Assistant Utilities Director Jarrod Biggs. The city spent $1 million in summer 2016 to create two features just above the park with the purpose of diverting more water into the city’s water intake for municipal use.

But in 2017, high water dislodged boulders, and the power of the river carried them downstream. The boulders are not grouted, or cemented, to the river bed – as required by the Army Corps of Engineers, Metz said. Sustained high water in 2019, with flows for weeks remaining over 6,000 cubic feet per second (the Animas usually peaks at around 4,700 cfs), again dislodged boulders.

The city has been planning to replace the dislodged boulders for about a year, Metz said.

The new construction allows some more space between the first and second drop – large enough “so boats can get in an extra paddle stroke,” Biggs said. Design engineers also have suggested adjusting the position of some boulders to make them more resilient to high-water flows, he said.

But, overall, the design won’t differ much from what existed in the Whitewater Park after it was repaired for the first time in 2017, Biggs said. He called the work “robust maintenance” – and this isn’t the last time the city will be in the river to address the features it built in 2016. The plan is to finish construction by the end of March.

“I think it would be unreasonable to say we’ll never have to do this work again. As our design engineer always says, ‘The river always wins,’” Biggs said. “We’re hopeful that this solution and some of the really big rocks that we were able to obtain will gird some of these things where we don’t have to do it as frequently.”

The city has worked with rafting companies “to build consensus on the best path forward,” Mickel said. While he was out of town during a meeting between the city and rafting companies, the city briefed him about the meeting’s feedback and asked his opinion about design and feasibility, he said.

“The city is doing the right thing. I think they built a plan based on consensus and input,” Mickel said. “They’re protecting the water intake and giving due consideration to river runners.”

bhauff@durangoherald.com