Studies: Estuary good for budget, animals

By John Dodge | The Olympian • Published September 04, 2008

OLYMPIA – Supporters of a Deschutes River estuary gained some ammunition Thursday with the release of two studies that show an estuary outshines Capitol Lake on at least two fronts — dredging costs, and fish and wildlife habitat.

Dredging costs to restore Capitol Lake to 13 feet deep and maintain it for 50 years are some three times more expensive than restoring the estuary and dredging river sediments out of lower Budd Inlet.

In 2008 dollars, the range of likely dredging costs for the lake are $166 million to $274 million while managing sediment associated with a Deschutes River estuary, including dredging in lower Budd Inlet, could cost $58 million to $88 million, the $70,000 study by the Seattle-based engineering consultant Moffatt & Nichol says.

"This is a very significant report," said Olympia City Councilman Joe Hyer, a member of the Capitol Lake management steering committee that's been studying lake versus estuary options since 2003. "The estuary folks have a leg up on the cost comparison."

Despite the dredging cost difference, not everyone thinks changing Capitol Lake into an estuary is a good idea.

The formal position of the Thurston County Chamber of Commerce for 15 years has been to maintain the lake because of concerns an estuary could hinder economic development and recreational opportunities, chamber president David Schaffert said.

An estuary would allow sediment to flow freely into the lower inlet, gradually reducing the water depth without regular dredging, and could hinder boat traffic at the Port of Olympia, Olympia Yacht Club and other local marinas, Schaffert said.

"The costs involved would be almost prohibitive for the Olympia Yacht Club to deal with," club member John DeMeyer said. "The downtown waterfront is at risk with the estuary proposal."

An estuary would change the character of the area, as well, Schaffert said, adding the state Capitol would no longer reflect off a lake, and views would change dramatically from Heritage Park.

The estuary option is less costly because it involves less dredging and uses dredged sediments to recontour the former lake shorelines. Dredge disposal costs are the big-ticket item and vary greatly depending on whether river deposits are dumped in Puget Sound or hauled long distances to upland disposal sites.