Tumwater City Council reviews interlocal agreement for shared governance of Deschutes Estuary project

The Washington State Department of Enterprise Services (DES) presented a draft interlocal agreement for the Deschutes Estuary restoration project to the Tumwater City Council on Tuesday, Sept. 24.

Under the project, the Fifth Avenue Dam will be removed, and the Fifth Avenue Bridge will be reconstructed to restore the Capitol Lake into an estuary.

Project consultant Tessa Gardner-Brown told the council that the restored estuary will extend two miles from Tumwater Falls to the Fifth Avenue Bridge once the project has been finished. The consultant added that the project will allow more unrestricted access to salmon runs and provide access to recreation.

The proposed interlocal agreement establishes the responsibilities of the different project partners.

For Tumwater’s part, the city will contribute funding towards maintenance dredging activities on Budd Inlet once the Fifth Avenue Dam has been removed. The dam removal will cause more sediment to flow into Budd Inlet.

Tumwater would contribute around 12% of the dredging costs, projected to total $7,673,000 by the end of the interlocal agreement in 2050.

Other entities involved in the project are Olympia, Thurston County, Squaxin Island Tribe, and LOTT Clean Water Alliance.  Project consultant Sarah Reich noted that the county has agreed to manage the funds each local entity will contribute.

Asked by Councilmember Michael Althauser about the protection provided to those funds, Reich stated that funds from the state will be separated to protect the local fund in case the legislature reallocates the money.

South Basin boardwalks

The proposed agreement also determines what properties will be transferred to some partners after the project’s completion.

According to the agreement, the city will own the planned boardwalks on the south basin of Capitol Lake once the dam has been removed.

Conceptual rendering of the north basin of Capitol Lake before and after the project. The third image shows what the estuary would look like during a …

Preliminary designs, specifically the 15% design, of the boardwalks have already been produced, according to Gardner-Brown, so Althauser inquired whether community outreach has already been done to ask the public about the proposed boardwalks.

Ann Larson from DES, who is also the project director, said that public engagement went into the 15% design documents and added that they will continue to engage the community in the next stages of the design process.

“We've only had one public meeting so far, and I think it was really successful, but we've established a community sounding board with folks from around,” Larson said.

“We don't have full funding yet, so funding is also a consideration. We need to make sure that we're thoughtful about how we use our limited funds until we receive more,” the projected director added.

Other benefits

Another benefit expected from the project is a reduction in flood elevation in Olympia by around one foot.

Althauser inquired about the project’s impact on flooding in the location of the Old Brewhouse Tower, which the city is working to restore.

Gardner-Brown acknowledged that the old brewery is within a mapped floodplain and said that their modeling projects that maximum flooding elevation in the old brewery’s location will be reduced as a result of the project.

“The flood elevations that occur now are higher than the maximum flood elevations that will occur in the future as a result of the project,” the consultant said.

“The trick and the nuance here is that the area will be more susceptible now to the change in tidal elevations so there may be higher water elevations more frequently as a result of high tide events, but the highest level of flooding will be reduced overall,” Gardner-Brown added.

The project also includes the creation of new habitat using material dredged from under Capitol Lake. Althauser asked why this project component does not extend beyond I-5 towards the area around Tumwater Historical Park.

Gardner-Brown responded by saying that the habitat around the park is already of good quality.

“It's the type of shoreline habitat that we are intending to develop across the project area so there is no need to enhance the habitat that is already so good in that project area,” Gardner-Brown said.