By Brian MIttge, The Chronicle, 2/14/2002
An extensive system of levees and improvements to the Skookumchuck Dam is now the Army Corps of Engineers, preferred choice to reduce flood damage and keep Interstate 5 from being inundated in another 1996-level flood.
This was the word in a Wednesday night briefing for elected officials from cities and counties affected by the overflow from the Chehalis, Newaukum and Skookumchuck rivers.
The message got a mixed reaction from Centralia leaders, who said the plan would not protect downtown, parts of Harrison Avenue and Mellen Street, while a Chehalis tribal member worried water not flooding the Twin Cities would end up on his reservation.
The $60 to $70 million proposal comes after three years and $4 million in studies from the 1996 flood, and more than 75 years of Army Corps involvement in Twin Cities flooding.
''We'd like to finally get something done,'' said Beth Coffey, manager for the Centralia Flood Damage Reduction Project.
The levee plan had the best overall benefits for the cost over other alternatives, she said.
Analysis is still continuing on what combination of levees, channel excavation and flood plain modification would produce the best ''bang for the buck,'' Coffey said.
A levee-only system -- likely the cheapest alternative -- would include the following floodwalls protecting the cities and interstate:
-- From Salzer Valley Road south around the fairgrounds to the I-5 bridge over Salzer Creek, then up just west of the freeway to Mellen Street.
-- From Harrison Avenue south and west around Fords Prairie and north to Galvin Road.
-- Around Sunbird and Yardbirds.
-- On the east side of I-5 from Chamber of Commerce Way up to Salzer Creek, then southwest, building on the existing airport dike, which would be raised or widened. Riverside Golf Club and nearby development would still be outside the dike.
-- On the west side of I-5 south of exit 77 and northwest of exit 76.
Extreme floodwaters on the river side of the levee would be slightly higher in the Chehalis area, said Albert Liou, engineer for Lewis County's consulting firm Pacific International Engineering.
Those high waters would be reduced by two optional proposals that are still being evaluated, he said.
One project that has the best chance of still being selected is to create a floodway under State Route 6 west of Chehalis to allow high water to bypass the Chehalis area by filling the large fields west of the river.
Without this proposal, the levees around parts of Chehalis would increase floodwaters in a 1996-type flood about six inches near the confluence of the Chehalis and Newaukum rivers, said Liou.
If the state Route 6 floodway was built, water levels would actually go down six inches in the same area, he said.
Less likely to happen is an expensive plan to open the narrow bottleneck at the Mellen Street bridge, creating a new flood channel to the northwest and building a new bridge that wouldn't back up water in a big flood.
Without this proposal water outside the improved Airport Road dike could be about six to nine inches higher in a 1996-level flood, Liou said.
If the floodway is expanded, levels in Centralia could go down dramatically, with a two-foot reduction in a 1996-level flood possible, he said.
Those two proposals, although expensive, would reduce flooding enough that some of the levees wouldn't have to be built, Liou said.
Centralia Mayor Tim Browning said the plan wouldn't solve flooding in downtown Centralia, on parts of Harrison Avenue and on Mellen Street. He called those omissions unacceptable.
''It appears traffic moving on I-5 has value but trashing downtown doesn't,'' he said. ''I object to that.''
The Corps can only look at flooding from major rivers such as the Chehalis and Skookumchuck, Coffey said. They are prevented by law from spending federal money on flooding from something as small as China Creek, no matter how devastating it might be.
''(The project) doesn't protect everything,'' Coffey said in her presentation. ''We do recognize that ... I have to be able to justify the reduction with the cost.''
Centralia is welcome to use the multi-million dollar floodplain computer model created for the project if it wants to sponsor a China Creek flood control measure itself, Pacific International Engineering Manager Harry Hosey said.
Liou offered to examine ways to reduce China Creek flooding, perhaps by pumping excess water overland to the Skookumchuck River.
However, ''at this point we have no real conclusions,'' he said.
Modifying the Skookumchuck Dam to hold back more water was central to every proposal the Corps seriously considered, but those dam improvements have been on the table for 20 years.
The moribund proposal was jolted back into life after the 1996 flood.
The Washington Department of Transportation, which was looking at a $100 million project to raise and widen I-5 through the Twin Cities, offered to pay the 35 percent local match to build a project that made raising the interstate unnecessary.
Now the DOT source of funding has dried up, a victim of the tight budget times.
''We have no more money,'' said DOT Southwest Washington Project Lead Bart Gernhart. ''I can't possibly do any major remediation. We're into paving roads and maybe finding a few places to do safety work.
Securing additional DOT funds from the state Legislature is just the first challenge waiting for the flood control efforts.
The Corps is on a tight deadline to create a final proposal by June for submission to Congress by September, with hopes of securing funding for studies in 2003.
The earliest dirt could be moved -- in a best-case scenario -- is 2005, Coffey said.
She noted that President Bush has not supported new Army Corps starts for several years, so it's up to Congress to insert the project into the budget.
Aids of Rep. Brian Baird, who sits on the House Transportation and Infrastructure Committee, and Sen. Patty Murray, who heads the Senate Appropriates Committee, were in the audience, along with about 50 city officials, county commissioners and concerned citizens.
The Skookumchuck Dam, originally built to supply water for the Centralia Steam-Electric Plant, would probably be purchased by a flood control district, Hosey said. It could also store water through the summer to be released to help improve river conditions for fish.
Hosey said none of the plans would increase flooding downstream -- any flood level increases from the levees would be localized, and would be more than made up for by the capacity from the improved dam.
In heavy rains the dam would be drawn down, adding an extra 23,000 acre-feet of water storage capacity.
That water would be slowly released after the flooding event was over, slightly reducing the flooding downstream, he said.
Chehalis Tribal Housing Authority Chairman Curtis DuPuis has his doubts, especially considering the new filling required for the levees.
''If levels are lower in Centralia and Chehalis it must be higher downstream,'' he said.
Grays Harbor Commissioner Bob Beerbower liked the plan, especially the ability to release extra water throughout the summer to cool the river and help salmon.
''There's a benefit for all the counties,'' he said.
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Brian Mittge covers local government for The Chronicle. He may be reached by e-mail at bmittge@chronline.com, or by telephoning 807-8237.
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