Small landslides Tuesday morning closed one lane of Highway 99W in Tigard and one lane of Highway 30 in Portland through at least Wednesday.
Oregon Department of Transportation officials said the Tigard slide was reported just before 3:30 a.m. and crews were dispatched immediately. Geologists then checked the stability of the hillside to ensure that removing the earth from the roadway was safe.
A sanitary sewer trench at a housing development excavation site failed, causing the slide, according to Tigard City Manager Marty Wine. The trench collapsed under heavy rain and snowmelt.
The right travel lane of 99W was closed near Bull Mountain Road. Crews hope to reopen it Wednesday
Another landslide blocked Highway 30 at Northwest Mill Road early Tuesday morning. Eastbound traffic was getting through in the left lane. ODOT officials said the right lane would be closed through at least Wednesday morning.