Did development, logging set the stage for disaster?

For more than a decade in the Chehalis River watershed, developers have been allowed to roll the dice.

In 1996, the worst flood Lewis County had ever known blew through, drowning communities in muddy water high enough to close Interstate 5. Since then, the county has granted more than 100 permits for new development in the floodplain. The cities of Centralia and Chehalis added to the rush.

Big-box stores, restaurants and strip malls galore. A railroad line extension, parking lots for a church. A coal-unloading facility, a new natural-gas pipeline, a mine expansion. And barns, homes, carports and shops. All built in the floodplain.

Then last Monday, heavy rain punched into the watershed from the southwest. Faster than anyone had ever seen before, torrents of water gouged hillsides, broke levees and overtopped dikes as flood gauges reached record highs and some blew out altogether. At the worst of it, some 10 feet of water covered parts of Chehalis, and hundreds of people watched their homes and belongings go under. One man was swept away in the deluge.

Now as the water recedes and residents of Lewis County take stock, many are looking back in time, wondering how much the legacy of development in the floodplain, and clear-cut logging in the upriver drainages, contributed to their woes.

Many state officials and regional experts, including a former county manager who says he was fired after criticizing floodplain development, say they have been warning for years that the hunger for development was running counter to common sense.

They note that while many counties, including neighboring Thurston, have either banned or seriously crimped development in the floodplain, Lewis County has not.

"It's kind of sad, we keep repeating the same mistakes, even when we know better," said Andy McMillan, a longtime wetlands manager for the state Department of Ecology. "It's the same old things coming into play: There's money to be made, and people want to make the most money for their land."

But in the wake of the storm, Lewis County leaders still say it's unfair to blame them for nature's wrath. And they predict the development will go on.

"The floodplain in the Chehalis is so vast that the filling in the floodplain for local development has no significant impact," said Bob Nacht, the director of community development for the city of Chehalis.

Moratoriums considered

To a large degree, this latest debate is a bit of déjà vu to the people of Lewis County.

After the 1996 flood, arguments broke out about getting tough on development in the floodplain.

"Bans or moratoriums have been considered on many occasions," Nacht said. Locals had debated a moratorium after the flood in 1986, too. And again in 1990 and 1991, 1996 and 2000.

But such talk gets little traction in the "Twin Cities" of Centralia and Chehalis, where as much as 70 percent of the city limits are in the floodplain, according to the county. Cutting floodplain development means cutting economic development in communities that say they need all they can get.

Instead, city leaders focused on making sure new development was built on fill — enough to bring it above the 1996 levels.

It's not that they didn't expect more damage. It was just seen as acceptable risk. "We are certainly not going to guarantee any development won't get flooded here," Nacht said

And in their defense, they point out that their rules are actually tougher than existing state and federal rules.

"As long as the pressure is on the government to permit development in the floodplain, these kinds of events will continue to occur, and we will continue to have damage," Nacht said.

Effects are cumulative

Though Lewis County isn't the only place where floodplain development is allowed, others have cracked down.

While individual filling projects might not appear to have an impact, the cumulative effect of repeated development in a floodplain can mean big trouble, the experts argue. It's like putting bricks in a bathtub. One brick displaces a little water. But a lot of bricks can force the tub to overflow.

"The more stuff you put in a flood plain, the higher the water the will rise," said David Montgomery, a scientist at the University of Washington who has studied the history of rivers in Western Washington.

Some local jurisdictions have decided state and federal flood-prevention standards are not protective enough and have gone much further.

Fourteen years ago, even before the 1996 floods, Thurston County banned all new development in its floodplains.

"We had a lot of flooding problems and we didn't want to perpetuate the situation," said Mike Kain, Thurston County's manager of planning and environmental services.

It still floods every year in King County. But King has the best insurance rating of any county in the nation from the Federal Emergency Management Agency, according to Jim Chan, director of building services. That's because of restrictions on development in the floodplain.

While he was public-works director for Lewis County, Mark Cook pushed county commissioners for stricter building regulations in the floodplain. "The cities came unglued," said Cook, who lives in Centralia. "There is a way of doing business that has been around a long time."

The county commissioners fired Cook in May after about four years on the job. One commissioner said there had been a "clash of wills," the local paper reported. Cook now says there were a number of reasons, but one was his opposition to continuing to fill and develop the floodplain.

"Change is hard, and sometimes the messenger doesn't always survive the task," said Cook, who now works as a private consultant for a variety of clients, including Lewis County. "No one wants to hear their current allowable permitting practices could have adverse consequences."

Clear-cuts increase risk

All the while Lewis County has debated its floodplain development, logging has been chewing through the forests in the Chehalis watershed since the last flood.

Logging has declined overall in Western Washington in the past 15 years. But the most intensive cutting is still happening on the type of industrial forestlands that dominate the Chehalis watershed.

Since 2002 alone, about 230,972 acres of the watershed — up to 14 percent of the forestland there — have been logged, according to the state Department of Natural Resources.

It's only about 2.3 percent of the watershed a year. But the effects of clear-cuts and logging roads stick around for years, potential ticking time bombs for large landslides, said Gordon Grant, a hydrologist for the federal Forest Service's Pacific Northwest Research Station in Corvallis, Ore. Landslides can happen anywhere, including on forested ground. But forestland that has been clear-cut is up to five times more likely to slide in flood conditions, and forestland with logging roads is even more vulnerable, Grant said. Those landslides can bring down logs, creating debris flows that stop up streams, culverts and even rivers.

That means even more flooding when the big rains finally come.

Last week, they did.

Chehalis watershed huge

This flood was far more damaging than the one in 1996. The water rose faster, and it flooded places that no one remembers being inundated before. There's no question Mother Nature threw her all at the watershed as a weather system barreled in from the southwest.

And geologically speaking, the Chehalis floodplain is a particularly bad place for that kind of punishment. It's broad and flat, and the watershed is huge — the second largest in the state. Drainage is naturally problematic in many places because of a layer of impervious clay just below the shallow soil.

Floodwater high up the Chehalis River stripped gargantuan loads of silt and timber off the hills, and dumped it along with the water that swamped homes, garages and barns to depths of up to 12 feet in some upriver communities, far above levels anyone can remember.

As the high water has retreated, it has left thousands of pieces of wood scattered across fields in the Boistfort Valley, which straddles the south fork of the Chehalis. One rugged, heavily logged drainage was scarred with dozens of landslides that spewed into a creek. Some slides clawed deep ravines.

In one large clear-cut alone, nearly a dozen slides emptied into a creek. In some areas, log jams may have acted like small dams, temporarily holding back water until they toppled over or breached. Some upriver communities got slammed with the mess. Then the floodwater moved on, all the way to the cities of Chehalis and Centralia and the development in the floodplain along I-5.

"There's a lot of stuff in the floodplain that wasn't there in 1996," said Jim Park, senior hydrologist for the state Department of Transportation. "The water goes somewhere; it doesn't just disappear."

Some neighborhoods in Chehalis and Centralia were flooded for the first time ever.

More fill likely in future

As the floodwater recedes over much of Lewis County this weekend, it's too early to tell whether development policies will be different.

But in Chehalis, Nacht said the city plans at least one change: It will demand even more fill in the floodplain. Future development will have to be built on fill piled above the level of this latest disaster, he said.

The city's claims that continued building in the floodplain has no impact is baffling to some experts.

"Fill will have an effect, and those effects will be local," said Park. This flood needs to be analyzed to understand what happened, he said.

"For someone to stand up and say it didn't have any effect is premature, and to say so flies in the face of the whole basis for having regulations."

Dan Sokol, who coordinates flood-insurance programs for the state Ecology Department, said this flood should at least teach that development planning needs to take into account everything from clear-cutting in the headwaters to development in the floodplain.

Tougher restrictions on building are also needed where the river has been known to flood — and will surely flood again, Sokol said.

"The more things you put in the floodplain, the more things are at risk," Sokol said. "We can never assume we have seen the worst of what nature can do."

Montgomery, the UW scientist, argues that commercial and residential floodplain development ends up costing everyone else.

"We should not be subsidizing those land uses through flood-control measures and rebuilding things and bailouts," he said. "The question is why did we build there in the first place?"

Despite the devastation last week, the critics appear unlikely to change many minds in Lewis County.

"If you didn't allow Wal-Mart to come in, people would say, 'Why are you stifling economic development?' " said Bob Johnson, the community-development manager for Lewis County. "It's a really hard balance. I understand why this development is happening."

The current attention on the floodplain ignores the fact that most building in the county is not in the floodplain at all, Johnson said.

"We try to put it where it's dry."

Lynda V. Mapes: 206-464-2736 or lmapes@seattletimes.com

Staff writer Hal Bernton contributed to this story.