May 8 Daily News editorial

The more than $10 million in federal stimulus money headed Southwest Washington’s way this spring via the U.S. Army Corps of Engineers will bring jobs and, for a good number of area residents, some peace of mind. The Corps will use the money to pay for five projects, three of which involve flood protection. Most notable among those three is the $2.8 million project dedicated to strengthening the Castle Rock levee.

Many Castle Rock residents will remember some anxious moments during January’s flooding, wondering whether the levee holding back a fast-rising Cowlitz River would hold. Corps engineers had given those counting on the levee plenty to worry about the previous summer.

A Corps analysis of flood risks found that Castle Rock was more vulnerable than previously thought. The study shortened the odds of a big flood in any given year — from 1 in 160 to 1 in 80. Also, the Corps decided that future so-called 100-year floods would be bigger than in the past. But the study’s most unsettling estimate for Castle Rock residents involved their levee’s stability. It was more vulnerable to failure than previously believed. Corps engineers estimated that there was a 1 in 5 chance the levee would fail during the next 100-year flood on the Cowlitz.

The Castle Rock levee was constructed on a layer of permeable sand, according to a report on the Corps’ 2008 study by Daily News city editor Andre Stepankowsky. This makes it vulnerable to seepage. If a major storm raises the Cowlitz for an extended period, Stepankowsky reported, water could seep through that permeable layer, erupting in “boils” on the landward side of the dike and eventually washing out the dike’s very foundation.

To fix this problem, Corps engineers plan to dig a trench 40 feet deep along the crest of the city’s north levee and fill it with impervious material the Corps refers to as “plastic” concrete. This will create a barrier to prevent water seepage under the dike during major storms.

The problem’s solution was fairly straightforward. Its cost was Castle Rock’s big hurdle. Credit the Corps’ Portland District and U.S. Rep. Brian Baird, D-Wash., for keeping this project on a front burner and making sure that it would be among those projects sharing in federal stimulus money. The work is expected to be completed this summer, meaning Castle Rock residents will not have to sweat out another flood season with a levee deemed suspect.

It also may mean less expense for those in Castle Rock with property in the floodplain. Daily News writer Barbara LaBoe reported last week that, without the work, the city’s levee certification and flood protection status was in jeopardy. Castle Rock Public Works Director Dave Vorse told LaBoe that losing federal certification could prompt banks to require property owners with loans within the floodplain to buy flood insurance.

Cowlitz County Commissioner George Raiter was right about this stimulus money, which also will pay to dredge parts of the Cowlitz and improve the Toutle River sediment-retention dam. As he told LaBoe last week, “It’s good news for the area in many ways.”