Workers began removing a troublesome berm along the banks of the Deschutes River on Thursday, the most visible step yet in an eight-year process to reunite a disconnected floodplain with the river. The change would help attract some plants and animals that left because of poor habitat conditions, including the Oregon spotted frog, according to the U.S. Forest Service.
“The potential of the site has not been reached for so long,” said Peter Sussmann, soil scientist with the Deschutes National Forest.
Earlier this week, Forest Service workers began work on a construction project designed to restore river access to the Ryan Ranch floodplain, a 65-acre parcel about 10 miles southwest of Bend near Dillon Falls, by building two channels from the flood plain to the river.
The land once served as a marshy outflow area for the Deschutes River. But decades of farming in the area created a large, earthen berm — which serves as part of the Deschutes River Trail — and that cuts off access to the river.
“That’s an appreciable amount of basin that has not seen enough water to support willows and sedges,” Sussmann said.
Kevin Larkin, district ranger for the Bend-Fort Rock Ranger District of the Deschutes National Forest, said Ryan Ranch was long used for cattle ranching, and ranchers wanted the floodplain relatively dry for grazing purposes.
“It’s an artificial construction that keeps the water from entering and leaving the way it historically would,” Larkin said.
Sussmann said the berm was originally built a short way away from the banks of the Deschutes River. Through the years, as water levels in the Deschutes rose during irrigation season and fell in the fall and winter, the river eroded its banks to the point that it has run up against the berm, leading to increased sedimentation, the loss of riverside vegetation and damage to the river trail, Sussmann said.
Larkin said the Forest Service began planning a project that would reconnect the basin with the river about eight years ago. In 2015, the Forest Service installed two pipes with shutoff valves, designed to inundate the basin without water to simulate how a more permanent outflow might impact plants and animals in the area.
Sussmann said the willows and sedges quickly returned to the area, along with sandhill cranes and other migratory birds that once used the floodplain.
“It quickly became an Audubon Society hot spot,” Sussmann said.
The current phase of the project includes using an excavator to move the berm away from the river and lowering the banks of the river by up to two and a half feet, according to Sussmann. A new, smaller berm will be built away from the river to support a rebuilt section of the Deschutes River Trail. Two open channels will be built to reconnect the river to the floodplain, with bridges spanning the channels.
The Oregon spotted frog, which was listed as threatened under the Endangered Species Act in 2014, used the Ryan Ranch area historically as part of its habitat, he said. However, the frogs need shallow water with creekside plants during mating season, as well as deeper areas to hibernate during the winter, conditions Ryan Ranch hasn’t been equipped to provide recently.
“By far, the biggest benefit this project will bring will be for the Oregon spotted frog,” Larkin added.
Sussmann said he was optimistic that construction will be wrapped up by Dec. 15, though bad weather could extend the timeline. After this phase is complete, construction crews will return in 2019 to build new facilities that comply with the federal Americans with Disabilities Act. A new toilet and new parking spaces will be built, and a short trail will connect visitors to an overlook with views of the basin.
“We can get more of the community out there to experience the site,” Sussmann said.
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