Frazer Creek surges along Highway 20
By Ann McCreary and Laurelle Walsh
A 4-foot diameter culvert installed this summer to contain runoff from the Leecher Creek drainage became plugged with mud and debris brought down by rain Thursday afternoon (Dec. 11) and sent water over State Highway 153 again.
The culvert was installed after a deluge of mud and debris swept down the drainage following a summer rainstorm on Aug. 21, damaging the road surface and destroying a home on the other side of the highway.
Washington State Department of Transportation (WSDOT) crews were unable to clear the culvert Thursday afternoon, and used a backhoe to divert the water coming down the drainage into a roadside ditch running along the northbound side of the highway.
The backhoe created a temporary channel across two driveways to provide a continuous channel about 1,000 feet north from the Leecher drainage, carrying the water to an abandoned irrigation ditch where it could disperse, said Jim Melton, a WSDOT maintenance technician.
Highway 153 remained open to traffic while crews worked, although motorists had to drive through several inches of water rushing across the highway at Leecher Creek, just south of milepost 25.
Runoff from the drainage “came down in a wall,” Jeff Adamson, WSDOT spokesman, said this week. “It was more like cement than mud.”
Although the culvert became clogged, the repairs made last summer did their job, Adamson said.
“As far as the road is concerned, for WSDOT purposes … the repairs we put in were essentially designed to fail safe if mud came down,” he said. “We put in deep enough shoulders to accommodate the mud and the water would flow over the road.”
Adamson said crews were on site most of the weekend working with a Vactor and a water truck “to blow out the culvert.”
Frazer Creek threatens bridges
Highway 20 also had water over it on Thursday at about milepost 207, in the same area where WSDOT replaced roads washed out by floods and mudflows in August when Frazer Creek became a torrent.
WSDOT armored ditches and shoulders along the road to prevent future damage to the road surface, and “it behaved as intended,” Adamson said. Some private properties along Highway 20 were reported to have sustained damage from water and mud, he said.
Water and tons of sediment rushed down Frazer Creek during the heavy rains, creating new channels and filling the newly engineered creek bed with a slurry of mud, sand and rocks.
Mike Miller is one of several residents living on the east side of Highway 20 on the way up the Loup, whose driveway crosses the creek on the way to his house.
Miller’s basement was flooded when Frazer Creek charted a new course during the deluge of Aug. 21. Until not quite two weeks ago, he and his neighbors had to drive through the creek and across each others’ property while WSDOT corralled the creek into a new rock-lined channel, repaired the highway and built new driveways and bridges.
“The bridge is holding,” Miller said, relieved that the new 16-foot-long, single-lane steel bridge that was finished less than two weeks ago made it unscathed through Thursday’s deluge.
Miller’s brother, who was staying at the house that night, told him that he could “hear it clanging” as rocks and boulders suspended in the water hit the steel rails under the new bridge, Miller said.
Until Thursday night, there was about 5 ½ feet of vertical space separating the underside of the bridge from the creek level below, Miller estimates. The space under the bridge is now filled to the top with sediment, with just enough of a gap to allow the water to flow through.
Miller had resisted WSDOT’s offer to build a berm between his house and the creek because he didn’t want to lose the aspen trees or the natural landscape between his home and the highway. But given the creek’s behavior of late, “I told them they could build the Great Wall of China if they wanted,” Miller said, as long as it would protect his home from future floodwaters.
Expect more problems
New culverts installed on Highway 153 at Canyon Creek and Benson Creek, which also washed out during the August floods, handled the runoff from last week’s rain, Adamson said.
WSDOT spent $3.4 million to repair the extensive road damage from last summer’s floods and mudslides. About $2.5 million was in federal emergency funding, Adamson said.
Adamson said the kind of problems that occurred last week are likely to be repeated as a result of the summer wildfires and the resulting risk of runoff from drainages burned bare of all vegetation.
“The ground is not going to stabilize itself or be revegetated in order to hold topsoil, the way it will eventually, for at least two years,” he said.
