King County to spend $1.4M updating landslide & flood maps

by TERESA YUAN / KING 5 News

Posted on June 13, 2014

SEATTLE -- In the aftermath of the deadly Oso Landslide, King County is making a new commitment to identify and prevent catastrophic floods and slides. The county's Flood Control District is spending $1.4 million to improve and update flood and slide maps over a two-year period.

King County leaders say the county's flood and landslide maps are old. They were last updated in the 1990s.

"There's always going to be landslides. There always has been. But now that the population is here, we really need to understand how those risk areas interface with the public," said Reagan Dunn, Flood Control District Chair.

Over the next two years, geologists will collect data and re-vamp flood and landslide maps.

The county is using LIDAR technology to dramatically improve the county's old maps. The general public will eventually be able to check out high-resolution maps which should be more accurate.

The goal is to identify the high-risk areas for severe flooding and major landslides and make that information easy for people to find online and understandable.

"A million dollars seems kind of expensive but it's one house these days. So if you said this project saved one or two houses, in those terms of property damage it would pay for itself," said King County geologist John Bethel.

Bethel says a couple of areas have active slides that the state and county are constantly monitoring, including on Highway 169, a spot on Auburn Black-Diamond road and the Tolt River.

Preliminary maps along major rivers will be available October 2014, and potential high-risks sites will be identified by December 2014.