Environmental groups and the Nez Perce Tribe have filed a lawsuit to stop proposed dredging of the lower Snake River to aid barge traffic from Lewiston, Idaho — the farthest inland seaport on the West Coast.
The lawsuit, filed Monday in federal court in Seattle, challenged the U.S. Army Corps of Engineers' approval of a $6.7 million dredging project scheduled to begin next month.
The lawsuit was filed by Earthjustice on behalf of a coalition of environmental groups.
The Army Corps contends that dredging behind Lower Granite Dam is needed to maintain the corridor for barges between Pasco, Washington, and Lewiston. Opponents contend barge traffic on the lower Snake River is declining and doesn't justify the dredging.
They also claim the dredging would hurt salmon, steelhead and Pacific lamprey.
The corps on Tuesday declined to comment on the lawsuit.
The corps' Walla Walla District released its draft sediment management plan two years ago, asserting that dredging and other maintenance would provide benefits far in excess of costs. Last week, the corps issued a record of decision adopting the plan, with work to begin on Dec. 15.
Four dams on the Lower Snake River between Lewiston and Pasco allow for barges that carry fuel, timber, agricultural products and other cargo. Environmental groups contend the dams should be removed because the structures sharply reduce runs of salmon and steelhead.
"These four dams are responsible for pushing the Snake River's wild salmon and steelhead to the edge of extinction." said Joseph Bogaard, director of Save Our Salmon.
The groups also say barge traffic has been dropping, which removes justification for dredging.
"Climate change and other factors are making the lower Snake River dams ever more deadly to migrating fish while the economic justification for this waterway is slipping away," Bogaard said.
The lawsuit contends the corps violated the National Environmental Policy Act and the Clean Water Act with its plan to remove about 400,000 cubic yards of sediment from the navigation channel. The lawsuit also says the corps failed to consider whether the work was economically justifiable.
The corps spent $16 million to prepare the plan.
The corps, seaport managers and farmers have said the costs of maintaining the waterway are justified. The agency estimates about 3 million tons of commodities are shipped on the river each year and moving them by barge instead of truck or rail saves about $8.45 a ton, or about $25 million a year.
The dams were constructed from the 1950s to the 1970s and made Lewiston and Clarkston into seaports.