Architect designs Oregon wetlands

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Nathalie Weinstein
Dolan Media Newswires

Portland, OR — Decades of ditch digging, damming and water diversion threatened to alter the Tillamook Bay basin’s wetlands forever. But Portland architecture firm Vigil-Agrimis Inc. worked for six years to design a plan to restore the area’s remaining wetlands to a natural state.

The Tillamook Estuaries Partnership in 2004 hired Portland architect Ken Vigil to design a master plan to restore 51 acres of wetlands near the Miami River in Garibaldi. The area’s winding streams had been reworked to become rectangular drainage ditches for farming purposes. While good for agriculture, the ditches make a poor habitat for the area’s salmon, which reside in the wetlands until they grow large enough to go to sea.

Determining where the area’s historic streams and water flows belonged was Vigil’s greatest challenge.

“The property is affected by river rain from the mountains as well as the ocean tides,” Vigil said. “River processes are straightforward; they change seasonally. Tides change daily.”

Without knowledge of how the wetlands functioned in the past, Vigil and project manager Maureen Raad traveled along the Oregon Coast and into Northern California to study similar bays and estuaries that were spared from human intrusion. Next, Vigil worked with engineer Hunter White to perform engineering studies on the existing streams and tributaries to estimate where, and how much, water flows into the area.

“When you don’t have a history of the stream flows, you have to use computer modeling to estimate,” Vigil said. “All these little streams have watersheds. If you don’t study each one, you don’t know the peak flows or how wide and deep your new channels need to be. It’s a fun design challenge, but it’s definitely a challenge.”

After gaining a better understanding of how water moves through the area, Vigil worked with the Tillamook Estuaries Partnership to design new water channels with natural curves. The site is the only spot along the Miami River that has both freshwater and saltwater, making it an ideal habitat for salmon, according to Rachel Hoffman, habitat restoration manager with the nonprofit organization.

But the present vegetation, grasses intended for grazing farm animals, did not provide the young salmon any natural protection from predators.

“We’re taking a very simple habitat and making it complex, which is what fish like,” Hoffman said. “We’re taking out the ditches and barriers, revegetating the site and adding large wood into the channels where the fish can hide from predators.”

Construction will begin on the site this summer. Existing drainage ditches will be excavated, meandering stream channels will be dug out, invasive plant species will be removed and native plant species will be planted.

For property owner Danny Crabb, seeing his land returned to a natural state is the realization of a dream.

Crabb in 2004 contacted the Tillamook Estuaries Partnership about performing a restoration project on his land.

Crabb and his wife, Janna, moved to the area in 2000 to open a bed-and-breakfast. The Crabbs fought several battles with a nearby sand and gravel operation to prevent further destruction to the remaining wetlands. The mine has since been sold.

“When we were fighting the mine, they called us names,” Crabb said. “Our guests had their tires slashed.

We were held at gunpoint on our property. That we’ve been able to save this land is pretty cool.”

International Line Builders Inc. of Tualatin is working to move utility lines from the site. Construction on the $350,000 project is expected to wrap up within a year.