Flood mitigation options discussed

There’s no escaping flood risks in La Conner, but there are temporary and permanent options that can improve the odds of successfully managing future high-water events like last December’s that caused nearly $2 million in damages.

Those options are spelled out in a flood mitigation report from engineer Evan Henke and presented to the Town’s Emergency Management Commission at Maple Hall May 9 by Public Works Director Brian Lease.

“This plan,” wrote Henke, of David Evans and Associates, “is intended to be a ‘living’ document that is frequently revised and amended as additional tasks are identified or completed.”

It notes the exposure to sea level intrusion via Swinomish Channel or Sullivan Slough and landward flooding from breaches in Skagit River dikes.

“One of the challenges facing the Town,” Henke reported, “is that the risk literally surrounds the urban area. There is only limited benefit in focusing on any one element or location when the system will fail due to the lowest point available.”

The commission devoted much of the 75-minute session to temporary measures that can be employed prior to flood season this year.

Those include placement of sandbags and ecology blocks to protect low-lying areas. Use of water-filled tube bladders received little support from commissioners.

“Water tubes,” said commission Chair Bill Stokes, “are vulnerable to a car backing into them or a knucklehead with a knife.”

Permanent solutions, which are more expensive, run the gamut from the oft-mentioned ring dike at the northeast edge of town and flood walls against saltwater encroachment.

“There is not a ‘one-size-fits-all’ solution for each location,” said Henke. “The final plan will likely be a patchwork quilt of measures tailored for each location and extent.”

Lease, who has done extensive research on flood protection, will develop budget estimates for the various remedies that commissioners can review, perhaps at their next meeting.

Stokes said the Town has about $100,000 available now in its flood management account.

“But we don’t want to spend it all on temporary measures,” he cautioned. “And we might need to seek grant money for permanent solutions.”

There are two simultaneous fronts for flood control: creating a temporary plan to deal with the next cycle of fall and winter flooding and addressing the long-term flood threats, including climate change.

“Long-term,” stressed Mayor Ramon Hayes, “we have to figure this thing out.”

“This year,” said Commissioner Jamie Throgmorton, "immediate temporary measures are needed. But in the future, we have to anticipate more than 14-feet (of tidal elevation). We can plan for 20-25 years ahead after we get done with the emergency planning.”

The Dec. 27 saltwater flooding was a 14-foot event.

Audience member Glen Johnson suggested the Town reach out to the City of Mount Vernon about the availability of its original flood wall structure.

“Something we might need for a quick fix,” said Johnson, “might be Mount Vernon’s old temporary flood wall. Something like that, we might be able to get fairly cheaply.”

Lease said storage is a key issue regarding all types of flood control equipment and infrastructure.

“It’s expensive,” he said, “and then you have the question of where to store it.”

And that’s just part of the commission’s focus. Preparation and response strategies related to earthquakes, tsunamis, fires, extreme weather and other emergencies are also their responsibilities.

Councilmember Rick Dole serves as liaison between the two groups. He termed the meeting “excellent” and praised Lease for his presentation of the work plan and ability to accurately and concisely answer all questions posed.

“It’s a detailed report,” Dole said, “and we have a lot to work with.”