UW Bothell campus will be a study in wetlands biology

By LUCY BODILLY
Special to the Journal

History is being made on the 127-acre site formerly known as the Truly farm, one of the last remaining bits of farmland near Bothell. It will soon be the site of the UW Bothell/Cascadia College Campus.

At the same time, the landscape is being rediscovered. The campus will share the site with 58 acres of wetlands, a riverine system restored to a near natural state.

Since the 1930s the site was used for agricultural purposes; the stream rechanneled and heavily leveed to prevent flooding. The project team hopes to restore the portion of the North Creek waterway near the confluence with the Sammamish River to a functioning condition.

We really dont want to refer to this as just a stream restoration, said Katharine Lee of L.C. Lee & Associates, the wetland consultant and landscape architect on the job. The company typically has one project of at least this size going at all times. With 12 employees, the firm is owned by Lyndon Lee, who is former Chief Wetland Biologist for the Environmental Protection Agency.

In addition to revamping the entire floodplain, the 58-acre restoration portion of the project includes rerouting over 1,000 feet of North Creek.

You have to address the larger landscape concept. You cant separate how the stream functions from its surroundings, she said. The flood plain has to be part of the system, because it dissipates the energy North Creek carries when it reaches its high water mark. And when the water overbanks, the vegetation in the floodplain helps clean it.

Lee worked closely with OTAK, the civil engineering firm, and scientists from the University of Washington, who provided peer review.

From the beginning the project was controversial. Opponents did not want to lose one of the remaining pieces of farmland in the area. Then, when the project was approved, they complained about the huge amount of money spent on restoration. Under normal circumstances, only 6 acres of upland wetlands would have had to be restored. Instead, the state decided to undertake one of the biggest freshwater wetland restorations ever in the Pacific Northwest.,

We could have done less and still gotten a permit, but there was a lot of time pressure so we wanted to make sure there was no room for argument. We went in with a plan that was way above what was called for. And after a certain point, you have to, because you cant halfway restore something, Lee said. The other factor was that the state was the owner, and could justify spending money for environmental purposes.

One way to return the area to its natural condition is to bring back the trees that fell in the floodplain, or at least some reasonable facsimiles. Reference studies showed that stream shape is driven by the amount and type of large woody debris in the stream channel. In talking to the UW scientists, the idea of using big wood kept coming up, Lee said. Unlike rock, which is usually used to stabilize streams, Lee chose engineered wood structures made of species-specific logs and recommended by the UW team of scientists.

The log jams also provide fish habitat and habitat for certain plant communities.

We wanted it to be as natural as possible, but also able to protect the surroundings, because we do have some critical items there such as a Metro sewer line, Lee said.

Work including stripping the floodplain area of all canary reed grass, digging mini-depressions to allow for puddling when North Creek swells and rechanneling North Creek. The initial phase of the project also called for hydroseeding with a native grass seed mixture. Active Construction of Gig Harbor did the sitework for the project. Northwestern Landscaping completed the initial landscaping work

Crews from Northwestern Landscaping just completed work planting willows, cottonwoods and dogwood along the stream banks. Those species were chosen first because of their ability to grow quickly and provide shade for upcoming plantings

Because they would have to provide a staging area for the large number of plants expected to go into the ground, Lee decided to use the staging area to grow about 20 percent of the plants, as well. These will be mostly trees that grow easily from cuttings, Lee said. After these plants take hold, the plan is to add some conifers.

In five to 10 years, Lee hopes there will be money for a bigger planting which could include native flowers. During the first three years about 25 distinct plant community types will be planted.

Two major threats remain for the project. One is the certainty that weeds will try to infest the area. The other is that it will not be properly maintained while the young plants grow.

Our biggest problem this year will be weed control, Lee said. Active Construction stripped the top layer of soil on the floodplain, but it would only take a few rhizomes of canary grass to start a new infestation. We may have to spot spray to keep it from taking over and that would be very controversial, Lee said.

The other question is who will be responsible for maintaining the site. Both institutions, the University of Washington and Cascadia Community College have agreed to undertake the responsibility, but neither is really set up for the work, or has the budget to do the job successfully, Lee said. The site needs heavy maintenance for the first five years. Then the restored site should provide a beautiful view for the campus and community and a legacy the state can be proud of.

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