The reconstruction of the Colorado Dam, which is scheduled to begin next week, will limit access to the Deschutes River, the Colorado Avenue footbridge and McKay Park for about a year.

While Miller’s Landing Park will remain open, adjacent trails will be closed and McKay Park will close for the duration of construction.

The Colorado Avenue footbridge will be closed. A detour will lead walkers, runners and bikers to the sidewalk and bike lane on the north side of the Colorado Avenue bridge and extend from the west side of Shevlin Hixon Drive to Carlon Avenue and Industrial Way east of the river. Barriers will be erected on the southwest edge of McKay Park to prevent access.

Those riding the current of the Deschutes, whether by inner tube or by kayak, must portage with their watercraft and proceed through a walking detour on Shevlin Hixon Drive before putting in again 600 feet downstream. The takeout will remain in its current location. A new beach will be built for the temporary put-in, a process that is expected to take about four weeks, according to Chelsea Schneider, a landscape architect for the Bend Park & Recreation District.

Street access is expected to stay open, but there may be temporary closures from time to time denoted by flaggers. Meanwhile, the city is making changes to sewer infrastructure in the coming months that may require additional closures in the area.

Preparation for construction, scheduled to be underway Oct. 1, began Monday with the removal of park features such as benches, water fountains, light fixtures and the plaza sculpture of geese, said Schneider.

Dam construction is expected to be finished in about a year. Work will continue in McKay Park and along the Deschutes River Trail through 2016.

Road, trail and feature closures may change depending upon the needs of the project.

“The only concerns would be water- and weather-related events that could happen on any construction project,” said Schneider. If water needs to be released from Wickiup Reservoir, or there’s a big freeze this winter, that could delay construction, though some leeway is built into the schedule to account for delays, said Schneider.

The project will create three distinct river channels, one each for fish passage, whitewater kayakers and wildlife that require calmer waters, such as frogs and birds. The fish passage channel will also be open to floaters, who will be able pass through the dam without getting out of the water once construction is complete.

Other highlights of the project include a new pedestrian and bicycle bridge and various amenities at McKay Park, among them new walkways, restroom facilities and a plaza overlook for the whitewater area, according to Schneider.

The amount allocated to the project is just more than $9.68 million. The park district’s board of directors agreed to put all remaining contingency funds from a 2012 bond measure toward covering the costs of the project after it awarded a $7.68 million contract to Hamilton Construction Co. on Sept. 16.

Voters approved a $29 million bond package for park improvements in November 2012. At that time, the cost of the Colorado Dam project was anticipated to be $6.3 million.

“What we have found through the finalization of this project is that costs are going up across the board,” said Schneider. “There were things that weren’t accounted for” in the initial estimation, including the true costs of water diversion, she said. “You’re actually damming part of the river and doing construction on one side, and switching it all back.”

The Bend Paddle Trail Alliance, a nonprofit dedicated to the promotion of local paddle trails, has pledged $1.1 million toward the cost of the project.

The dam is being reconstructed not only to improve recreational opportunities for paddlers and pedestrians, but also to make the area safer, said Schneider.

In the dam’s current form, a sheer drop of eight feet requires that those floating or kayaking the river disembark.

A 300-foot ramp will alleviate the river’s change in elevation and the current need for portage. Schneider described the new ramp as a series of 6-inch steps submerged deep under the river’s water.

“It’s an eight-foot drop, which is unsafe in any configuration,” Schneider said. “There’s all kinds of opportunities for people to get hung up under water.”

The Bend park district opened access to floaters on the calm parts of the Deschutes River in 2005. Since then, there have been several accidents in the Colorado Dam area, according to the district. A woman drowned after getting caught in the spillway under the Colorado Avenue Bridge in 2006, according to Bulletin archives.

The Colorado Dam was constructed in 1915 to create a pond for nearby lumber mills, according to the website of the Bend Paddle Trail Alliance. If all goes according to schedule, floaters and kayakers will have a chance to enjoy the dam’s new incarnation in its hundredth anniversary year.

— Reporter: 541-383-0376, cwithycombe@bendbulletin.com