Record-setting rainfall in December has left some local impacts that will likely be felt for quite some time.
On Monday, precipitation pushed past the previous high of 13.35 inches. Forecasters expect totals to exceed 14 inches by the end of the month.
In Camas, Forest Home Road was closed just more than two weeks ago after heavy rain showers caused a landslide on the south side, 1,500 feet east of Northwest Astor Street.
“What you can’t see is that on the downhill side of the road, about two-thirds of the way up the hill, there are two separate sections that slid out and essentially undercut the road in a couple of different areas,” Public Works Director Steve Wall told the City Council Monday.
City staff, and geo-technical and structural engineers have examined the slides, which are approximately 180 feet and 50 feet long.
“There are definitely concerns that the traveling public, if you are on that side of the road, any vibrations or weight on that side could make it slide more,” Wall said. “There is a danger there that people can’t really see. That’s why it’s closed.”
A “significant” fix will be required to make the area safe for vehicle, bicycle and pedestrian traffic.
“We don’t know yet what that is,” Wall said. “We are still doing the investigative work at this point in time.”
City officials are hoping federal emergency relief funding sources will be made available to help support the cost of the project.
The earliest time frame that construction might begin is summer 2016. The road will remain closed until the work is finished.
“The city asks that everyone be respectful of the road closure and find alternate routes until the road is reopened,” stated a city social media posting.
The steep, heavily wooded Forest Home Road, which provides a direct route to the top of Prune Hill, is no stranger to mud slides.
In December 2005, following a period of heavy rain, there was a 120-foot long surface slide that brought mud and trees down onto the roadway.
Geotechnical engineers determined that an area approximately 100 feet long, running parallel to the roadway, was unstable. Major repairs were required, and it did not reopen to traffic until November 2006.
Mud slides also occurred in that area in 1995 and 1996, damaging a portion of the roadway.
Lacamas Lane still closed
Another road that currently remains closed is Northwest Lacamas Lane, between Northwest 44th Avenue and Lake Road. A slide occurred there earlier this month.
Wall said once the weather dries out a bit, barriers can be placed in front of the slide along the sidewalk. The road can then be reopened and repair work completed on the hillside while traffic continues to flow through.
“With that one, we’ll wait and see how the weather turns out to make sure it’s not still moving on us before we go up there,” he said. “Hopefully, that’s a little more short-term closure than Forest Home Road.”
Precipitation has fallen in the area every day for the past 21 days. Severe weather continued on Monday, with heavy rain and strong winds forcing its way through Clark County and the Portland Metro areas.
More precipitation is forecasted for Tuesday and Wednesday, but conditions should then dry out for several days.