Crews planned a schedule of lane openings in order to allow some traffic through the mudslide-damaged stretch of U.S. 30 near Clatskanie until the roadway can be completely repaired.

Each night, crews will try to open one lane of the highway around 5:30 p.m. and then keep traffic flowing through 7:30 the next morning. Then, the roadway will be closed to traffic during the daylight hours in order for crews to make repairs.

The schedule will likely continue until the roadway is ready to be reopened permanently.

Most of the mud and debris had been cleared from the road but clogged culverts blocked water from draining along the highway and the runoff was crossing the road until crews used heavy equipment to clear some jams.

KGW rode along with geologists Thursday and other nearby landslide hotspots.

Nobody was injured in the slide Tuesday that covered an estimated three football fields in length near Clatskanie. But two homes were destroyed and others were hit by the slide.

Soon after geotechnical engineer Jason Hinkle warned the Oregon Department of Transportation that a huge mudslide was imminent near Clatskanie, debris buried Highway 30 and several surrounding homes.

Thanks to Hinkle and his colleagues, however, no one was injured.

A land owner sent Hinkle, who works for the Oregon Department of Forestry, and other workers up into the hills to survey storm damage. What they found prompted immediate evacuation. They saw a pond that had been formed after two separate landslides from the forest above slammed into a railroad grade below and blocked a culvert.

That culvert later broke loose.

"As soon as it started going, we started yelling, 'Get back, get back!" Hinkle said. "We called down to ODOT to let them know." Hinkle also captured the moment on video.

SLIDESHOWS:

Slide buries Hwy 30

Aerial view of mudslide

Clatskanie PUD

Highway crews with backhoes, dump trucks and snow-moving blades pushed a soupy mixture of gravel, mud and lumber off a state highway Wednesday after a mudslide slammed into homes and blocked the road.

But after working all night to clear U.S. 30, highway workers found that water was still flowing across it, posing a hazard both to traffic and the roadbed.

The river of mud and debris broke free just before noon Tuesday near Clatskanie, burying two homes, sweeping away another, and damaging a fourth.

There was no word on exactly when the popular route to the Oregon Coast would be re-opened.

"Crews worked through the night to clear the highway of debris. While much of the debris has been cleared, plugged culverts in the area are causing water to continue washing across the roadway. Crews continue to work as quickly as possible to reopen U.S. 30," said Christine Miles with the Oregon Department of Transportation. "U.S. 30 is expected to remain closed in both directions until further notice. Only residents who live behind road blockades will be allowed past the safety checkpoints."

More Video: Aerial view of slide

 Interactive: Simulation of how slide happened

Also: Two men arrested for burglarizing flood-damaged home

Engineers were trying to figure out how to stem or divert the water Wednesday morning. There was no estimate of how soon the road might reopen, said Christine Miles, spokeswoman for the Oregon Department of Transportation.

U.S. 30 runs along the Columbia River, linking Portland and the Pacific Coast. The area hit by the slide was part of the region damaged by recent major storms. Detour routes were set up between Portland to Astoria. Motorists were advised to use U.S. 30 to the Longview Bridge to SR 4 to SR 401 in Washington; or U.S. 26 (Sunset Highway) to U.S. 101 in Oregon. Use the reverse routes for traveling from Astoria to Portland. Motorists also have the option of using the Wahkiakum County Ferry, which connects Westport on U.S. 30 to Puget Island and Cathlamet, Washington, at SR 4.

The storms caused the mudslide, which is not uncommon in a region with steep slopes, weak rock beneath the soil and heavy winter rains, said Jason Hinkle, a geotechnical specialist with the Oregon Department of Forestry. More than 10 inches of rain fell on some parts of the Oregon Coast Range during the two storms.

"When you get that much water in that soil, it's basically a lubricant," said Rod Nichols, a spokesman for the forestry department.

Debris and water high above the highway plugged a culvert through an abandoned railroad grade, the water backed up to a depth of 40 feet and made a pond about 200 feet by 250 feet, Nichols said.

The company that owns the land notified the state days ago of the slide potential, but a contractor was unable to relieve the stress on the railroad grade, Hinkle said.

A map of the slide area.

So on Monday, people living below the pond were evacuated, and on Tuesday the highway department closed the road after Hinkle warned that the slide was imminent. He was proved right about an hour later. He and Nichols said the slide flowed about a mile and three-quarters downhill, reaching a speed of 30 mph to 40 mph uphill and then slowing before it oozed out over the highway.

More: Complete storm coverage

Clatskanie Fire Chief Dick Long said he heard the slide as it happened, noting it took about five minutes.

"It's just total devastation of that small community, brutal" Mayor Diane Pohl said.