Untitled Document

ITD Vault: 29 Years Ago
April 1986

Rain, snowmelt causes $1.7 million in damage

Heavy rains and spring-like temperatures caused an estimated $1.7 million in damage to the highway system in February with widespread flooding and rock slides through much of north central Idaho. Sections of U.S. 95 and State Highway 55 were closed for up to a week. One of the areas first hit was the Culdesac Canyon on U.S. 95 bordering Lapwai Creek. A washout Sunday, Feb. 23, wiped out a lane and a half of the roadway for about 100 feet at one location.

Lapwai Creek undermined and washed out the road in two other major areas as well. Traffic skirted the weeklong closure by using the old Winchester grade. That road, however, was open only to cars and light trucks with heavier traffic forced to detour through Oregon and Washington. Repair costs will exceed $250,000 in this area.

While Transportation Department crews were fighting to minimize the damage in Culdesac Canyon, a massive slide filled the summit of Whitebird Hill on U.S. 95.

Approximately 20,000 cubic yards of mud and rock was dumped Monday, Feb. 24, at 10:30 p.m. in a slide that measured 25 feet deep and 100 feet wide.

Two-way traffic was re-routed over the old Whitebird Hill Road, which had been out of use since the 1960s. On Thursday, Feb. 27, crews began piloting traffic over the summit one lane at a time creating a delay of about 30 minutes.

Trucks were forbidden to travel the old road after accidents caused major traffic jams earlier in that week but were allowed with the pilot cars. By 4 a.m. the morning after the slide occurred, state crews had mobilized to open the road. During the evening of Feb. 25, another slide broke loose, adding to blockage. Transportation Department crews, along with contractors, were still able to clear the road in a week. It was originally estimated the road could be closed up to two weeks.

Jim Clayton, District 2 Engineer, estimated $1.3 million will be needed to rebuild the top portion of the Whitebird grade, where a geological fault threatens to cause slides every spring.

U.S. 95 was also closed for short periods between Weiser and Payette because of the rain- and runoff-swollen Snake and Weiser Rivers.

Damage is estimated to be $8,000.

State Highway 55 was closed Sunday, Feb 23, because of an early mudslide north of Banks. It was reopened only to be closed early Monday, Feb. 24, until Tuesday because of more mudslides. Round Valley Creek overflowed at the south end of Round Valley and submerged part of the highway with three feet of water.

The removal of the slides, slope stabilization and repair of S.H. 55 is estimated to cost $25,000. Idaho Gov. John Evans has asked the federal government for emergency help to repair the badly damaged roads through the Federal Highway Administration. Included in this attempt will be the Banks to Lowman Road in Boise County and the Air Base to Grandview Road in Elmore County.

A state of emergency was declared in Boise County after flooding and slides closed many of the county's road. The declaration allowed use of the state's resources to clear the roads. Some 100 families were stranded in the Robie Creek area off Highway 21 after six miles of Thorn Creek Road was washed out.

Idaho National Guard units assisted in restoring and cleaning the road.

Editor’s 2015 Note: Jim Carpenter, now the department’s chief operations officer, was then a resident engineer working in District 2. He recalls the slide coming down at the top of the WhiteBird cut, on the north side. Carpenter said the road closed for about three days as crews removed slide material. Later that year, a contractor built the bench on the hillside that you see today. The event in Culdesac Canyon occurred in late winter. Carpenter said road-embankment material, roadway shoulders and parts of lanes washed out on U.S. 95 south of the town.