Pacific mayor blames Corps for flooding

The mayor of Pacific, a city of 6,000 in South King County, is blaming the Army Corps of Engineers for flooding on the White River that's displaced one-fifth of his residents.

But the Corps contends there's no way to know if its decision to release water from the reservoir behind the Mud Mountain Dam upstream from Enumclaw is a factor in the flooding that's inundated neighborhoods with up to 10 feet of water.

"There's no way to determine if our releases caused the flooding. There could be other factors," such as local creeks that have topped their banks or debris that's clogging the flow of the White River, said Andrea Takash, a spokeswoman for the Corps in Seattle.

Takash said the Corps began releasing 10,000 cubic feet per second (cfs) of water Thursday morning and plans to continue releasing that amount of water through the weekend. Water in the reservoir had almost reached capacity on Thursday and the releases are to meant to create room in the reservoir in the event of more rain, she said.

The Corps' staff meteorologist is forecasting light to moderate rain on Saturday, Takash said.

"It takes a few days to draw down the water in the reservoir. We can't wait — we have to get some of that water out, just in case," she said.

The Mud Mountain Dam is a flood-control facility that was originally constructed in the 1940s and then renovated and rebuilt in the 1990s. Water from the dam flows into the White River and ultimately, the Puyallup River. During the height of this week's storm, water was held back from flowing into the White River to alleviate flows in the Puyallup, Takash explained.

The reservoir behind the dam is 5 ½ miles long and has capacity for 106,000 acre feet of water, she said.

This week, the Puyallup River experienced peak flows of 41,500 cfs Without flood control at Mud Mountain Dam, those flows would've hit at least 70,000 cfs, Takash said.

Army Corps officials were surprised by the scale of flooding in Pacific.

They released similar water levels from Mud Mountain Dam during the Nov. 2006 floods, but then there was only minor "nuisance" flooding reported around Pacific, said Ken Brettmann, who oversees the Corps' reservoir control center for the region.

The dam was designed to release peak flows of 12,000 cubic feet per second, and the releases this time reached a maximum of 11,700 cfs Thursday evening. That matches the peak in 2006.

"The information suggested 'Hey, nusiance flooding can start up to 12,000 release, but nothing signficiant.' And so that's what we followed," Brettmann said.

He said it's hard to predict exactly how much flooding will occur downstream, because other factors could be at play. Other creeks flowing into the White River downstream of the dam could be higher. The river channel might have filled in with more gravel, shrinking how much water it can hold. Or new development could have put property in harm's way.

The dam's chief purpose is to protect property along the lower Puyallup, not the White River, because there is more infrastructure and property at risk there, said Brettmann.

Pacific Mayor Rich Hildreth said he doesn't think there's a question about what's caused "major flooding" in his city. Sandbags and swift-water rescuers were arriving this morning and a shelter has been set up in a conference room at City Hall.

Records from the King County's Office of Emergency Management show that someone from the flood warning center placed a call to the town's police chief between 1 p.m. and 2 p.m., alerting him that the Corps would be increasing the river's flow later that day.

Hildreth said the Corps told him at 2 p.m. Thursday that the plan was to release enough water for the White River to reach its banks. By 5 p.m., the water started overtopping the banks and by 6:30 p.m., residents were beginning to report significant flooding.

"The water just kept rising and rising," he said, breaking off the conversation to inform a city staffer that a forklift would be needed to move pallets of sandbags.

Houses that "were barely touched" during flooding in 2006 "are now under 6 feet of water and in some cases, 8 to 10 feet," Hildreth said, adding that flooded neighborhoods aren't located in flood plains or even listed on the federal government's latest flood maps, released last year. Roughly 1,200 people have been evacuated from neighborhoods near the White River, he said.

Water, mud and sewage are now flowing through the area around Pacific City Park.

"It's all sorts of bad, nasty stuff," Hildreth said. "I don't want to ever see this happen again."

Doug Williams, a spokesman for the King County Department of Natural Resources and Parks, said the Corps has a difficult job balancing "the needs for flood-storage capacity and impacts on communities downstream."

The Mud Mountain Dam is an impressive facility that's prevented millions of dollars in property damage over the years, Williams said. But the White River is notoriously volatile and it's possible that gauges in the water have been damaged by debris, shifted position or are somehow giving "an off reading," he said.

"I don't think anyone is really certain why the flows that the Corps' gauges show were released from the dam have caused the problems in Pacific," Williams said. "Unfortunately, Pacific is now having to deal with this high water."

Sara Jean Green: 206-515-5654 or sgreen@seattletimes.com. Warren Cornwall and Susan Kelleher contributed to this report.