No longer big risk of flooding in Portland area

By KATU.com Web Staff Published: Jan 7, 2009 at 6:58 AM PST Last Updated: Jan 7, 2009 at 1:15 PM PST
No longer big risk of flooding in Portland area »Play Video
Johnson Creek in southeast Portland Wednesday morning was not flooding the area.

PORTLAND, Ore. - The rain is coming to the Portland area, and high winds will blow things around - but widespread flooding in the Willamette Valley is not likely.

That's the latest forecast from KATU Meteorologist Rhonda Shelby as a Pacific storm continues to move into the Northwest.

The Portland area is now only expected to get 1 to 2 inches of rain through Friday, which could still cause some flooding problems but is far from the 3.25 inches the area received during last week's storm, when rivers swelled, land slid and plenty suffered damage to their homes.

"Here in the (Willamette) Valley, it looks like the risk has gone way down," she said.

Elsewhere in the region, however, plenty of areas could face trouble.

The northern Oregon coast and southwest Washington face the highest risk for flooding - and possibly also landslides - as they could see 3 to 4 inches of rain by Thursday morning, Shelby said. That area includes Tillamook and Astoria as well as Kelso/Longview and parts north in Washington.

The National Weather Service on Wednesday posted flood warnings for the Wilson, Trask and lower Nehalem rivers in Tillamook County, meaning flooding is imminent or in progress.

The following rivers are expected to reach flood stage in the next few days:

  • Wilson River - 3 feet above flood stage
  • Cowlitz River - 1 foot above flood stage
  • Nehalem River - 12 feet above flood stage
  • Tualatin River - .5 inches above flood stage
  • Pudding River - 1.5 feet above flood stage

Those numbers are down from previous forecasts.

The worst of the bunch will be the Nehalem River, which will be the only one in our area that will be high enough to be classified as a 'major flood.' It flows through Vernonia, where officials and residents were preparing for the worst.

Johnson Creek, a regular trouble spot in Portland, is expected to crest at 11.7 feet by Thursday afternoon.  That is 7 inches above flood stage but down from the old forecast of cresting at 15 feet.

The Willamette River is expected to hover at or near flood stage on Thursday and Friday. 

So how much rain can we expect to get?  Here's a look at the rain forecast:

  • Coast - 1.5 to 4 inches
  • Coast Range - 2 to 7 inches
  • Cascades - 2 to 6 inches
  • Valley - 1.25 to 2 inches

With all that rain soaking into the ground, Oregon Department of Geology officials are warning residents to watch and listen for the signs of a rapidly moving landslide, such as trees cracking or big changes in nearby streams.