This article was published on: 01/3/15 12:00 AM
Concerns about flooding in Bend lessen with higher temperatures
By Ted Shorack
Ice began to break and crack on the surface of the Deschutes River on Friday after subzero temperatures this week froze parts of the river between the Colorado and Galveston Avenue bridges and near Drake Park.
Officials monitoring the river said the water level had receded 7 inches Friday, a relief to homeowners who worried about flood damage when ice formations pushed water onto the river banks and froze.
Several backyards and city parks were flooded and frozen in the area. A boathouse in one resident’s backyard was partially flooded with ice forming inside.
What’s ahead
Warmer weather is expected to alleviate the situation as high temperatures rise into the high 30s and low 40s in the next few days. The high in Bend on Friday was 39 degrees, according to the National Weather Service.
Anne Aurand, a city spokeswoman, said officials would continue to monitor river flows in the next few days and watch for how the ice breaks up.
What happened?
The river rose between 8 and 10 inches from Wednesday into Thursday afternoon. Officials said high flows from the Little Deschutes are partly to blame for the rising levels.
Some residents wondered whether the Colorado Dam Safe Passage project had anything to do with the rapid freezing that took place overnight.
Don Horton, executive director of the Bend Park & Recreation District, said Friday the river’s flow hasn’t been disrupted by the project.
“What we’re doing upriver wouldn’t have any effect on the river freezing,” Horton said.
There were also questions about whether more could have been done to regulate the flow at the Mirror Pond dam owned by Pacific Power near the Newport Avenue bridge.
Michael Garrigan, a resident of NW Riverfront Street who had some minor flooding at his house, said the situation was likely preventable.
“I think what just happened was completely avoidable,” Garrigan said.
Mirror Pond dam
Bob Gravely, a spokesman for Pacific Power, said the pond was at normal levels when the freezing and flooding happened. The main way to regulate the water levels is at two gates where water passes through.
Gravely said the company took the hydroelectric plant offline Tuesday morning and opened one of the gates to allow water to pass through when ice was noticed near the intake section.
Opening the gate allowed the company to keep the pond level stable while the plant was offline. An operator opened up a second gate partially Thursday when he noticed the water level rising again, Gravely said.
Operators are now concerned that if the water is lowered too much, it might cause ice formations to get caught in the gates.
“If we were to drop the level further, the ice chunks would not be able to pass over and it could block up and we could end up with a more difficult situation,” Gravely said.
In the past
Ice clogged the river in 1983 and caused more than 100 homes to be flooded. Many residents living near the river remembered when the river froze several years ago. The short amount of time it took to freeze this week caught homeowners off guard.
The river’s frozen surface delayed the Colorado Dam project this week and postponed work until the ice begins to thaw.
“It’s put a little more pressure on the contractor to get their work done in a shorter time period,” Horton said.
Horton said crews will have to wait for the ice to melt before returning because breaking up the ice could cause the formations to bunch up downstream and exacerbate flooding.
The city and county handed out about 350 sandbags this week to residents along the river in case the water continued to rise and threaten structures.
— Reporter: 541-617-7820, tshorack@bendbulletin.com