Metro uses natural solutions to combat natural problems along the Sandy River
During the weekend of January 15th, storms dropped more than nine inches of rain in Clackamas County. Combined with two inches of snowmelt on Mount Hood, the Sandy River rushed downstream, reaching Oxbow Regional Park, where it washed away riverside trails and parts of campground areas, dropping trees along its banks.
"More than half a mile of trail was lost to the river," said Clyde Keebaugh, operations and maintenance supervisor at the park. "Horseshoe pits that were thirty to forty feet from the bank are now at the edge. Park staff is in the process of moving them away from the bank and rerouting the lost trails. All our other facilities are open to the public."
“Oxbow received its third highest flood water on record, but luckily it left mostly cosmetic damages," said Metro senior natural resource scientist Brian Vaughn. "The roads and campground are still intact which is good news for visitors to the park."
Though the park suffered some damage, with banks near one of the campgrounds washing away, others fared better.
"We have to remember that riverbank erosion is a natural process," Vaughn said, "and to preserve the scenic river we have to be careful to avoid fixes that are not natural, not scenic, and are expensive.”
One low-cost natural solution Metro has used to fight erosion is tying fallen logs to the edge of the river bank in areas prone to washouts. By slowing the speed at which the river hits the bank, it slows the rate of erosion.
The method showed promise during the recent flooding.
“The bank below the campground is one of the banks that we didn’t see very much slumping on, which is really good for Metro because we don’t want to lose the campground,” Vaughan said, standing on a muddy bank below a campsite where the tied logs were in use. “Ideally, we want to encourage natural processes without sacrificing our resources.”
"We have to let nature take its course, but for trees that are going to fall anyway, if we can control their fall and then lock them to the bank, we can capture the main energy of the river and prevent larger losses," Keebaugh said.
Oxbow Regional Park is located within the scenic Sandy River Gorge. It offers rare access to many of the region’s natural wonders while providing a variety of unique recreational opportunities, including swimming, rafting, kayaking, fishing and wildlife observation.