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The Impact – Lake to Estuary Conversion Project Update

Mike McClanahan profile by Mike McClanahan

For 70 years Capitol Lake has been a signature feature of the state capitol and downtown Olympia, but plans are in the works to transform the area back into an estuary. The lake was formed by the construction of the 5th Avenue Dam in 1951 which severed the connection between the Deschutes River and the Puget Sound.

Last fall the agency that manages Capitol Lake, the Department of Enterprise Services, announced the decision to eliminate the lake and restore the Deschutes estuary. That involves removing the dam which doubles as a bridge in downtown Olympia, constructing a new bridge for traffic, and reshaping the landscape currently occupied by Capitol Lake.

The cost estimates that appear in scoping publications from the Department of Enterprise Services and its hired project consultants range from $137 million to $247 million for construction, design, and permitting expenses.

After completion, ongoing maintenance dredging will present another large expense. The agency has estimated three decades of dredging could run between $29 million and $52 million.

The legislature approved $7 million for the project in its most recent budget. 

Proponents of the plan to restore the Deschutes estuary say it will improve the water quality on the saltwater side of the dam in Budd Inlet and benefit species like salmon on the freshwater side. They also predict it will reduce the prevalence of the invasive New Zealand Mud Snail, which was detected in Capitol Lake in 2009 and led to an indefinite quarantine of the lake which prohibits contact with the water. Estuary restoration proponents also emphasize the cultural and historical significance of the site for stakeholders such as the Squaxin Island Tribe.

Critics of the dam removal and estuary restoration project dispute claims about the environmental benefits of restoring the estuary. Some argue that transforming the lake back into an estuary will dramatically change the aesthetic in the state capitol for the worse, from the smell to the view. Critics of the lake to estuary conversion plan also worry that sedimentation will threaten the adjacent marinas and boardwalk business district, and some claim that the project will be far more expensive than the official estimates.  

The long running debate about what to do for or with Capitol Lake has been a divisive issue in Olympia for many years and led to the creation of grassroots advocacy groups on opposite sides of the issue.

The Capitol Lake Improvement and Protection Association, was formed more than a dozen years ago. Although he says they dropped the name, long-time CLIPA member Jack Havens, is still an outspoken advocate of saving Capitol Lake. He says independent studies conflict with the state’s conclusions about the environmental implications of eliminating the lake. He believes removing the dam would be a huge mistake. 

“Well, to take the dam out that is now protecting Capitol Lake, which is a very clean basin, taking the dam out will make that far, far less healthy environmentally. Not to mention the fact that it will virtually destroy recreation. It will harm the social value of the Capitol Lake Basin. There will be an odor. There always is, because this is a terminal urban estuary that has no place, we believe, in a capital city,” said Havens.

On the other end of the spectrum is the Deschutes Estuary Restoration Team. The organization was founded with the specific goal of returning the river mouth to its natural state. 

DERT Operations and Development Manager Casey Allen says the latest environmental impact statement reflects millions of dollars and thousands of hours of scientific research. He thinks the science clearly points to removing the dam as the best course of action for water quality in the nearby Puget Sound.

“Of the things that I’m most excited for and I think that are like the big highlights, I think thinking of an opportunity of taking my kayak from the falls down to the mouth of the of the Salish Sea here, I think of, you know, increased wildlife viewing. I think of having and truly dynamic habitat right here in the heart of downtown Olympia, but I also think of starting to whittle away at those 13 invasive species that are in the lake. I think of meeting our water quality standards for the first time in decade,” said Allen.

DES recently announced a new agency project lead for the Deschutes Estuary Restoration Project and the selection of a consultant design team.

“We’ve got the municipalities going to help fund the long term management and the sediment management once it’s constructed. That’s a big deal,” said Ann Larson, Special Assistant to the DES Director for Environmental, Energy, and Climate Initiatives.