Northwest Environmental Advocates--Channel Deepening

Columbia and Willamette Channel Deepening Project, cont.

Channel Deepening Will Harm Threatened & Endangered Species

Wake Erosion and Fish Stranding
Blasting
Entrainment
Caspian Tern Predation on Salmon at Rice Island

Wake Erosion and Fish Stranding

Ship wakes erode land from the sides of the river and lift young fish above the water line, stranding them high and dry on river banks. The Corps downplays the potential for stranding and argues that erosion problems are unsubstantial because the Columbia's natural banklines are erosion resistant. However, unstable dredged material from past sediment disposal makes up 85 miles of river bank, half of the Columbia River's shorelines. The Corps describes these sites as highly susceptible to erosion. Thus any increase in the size, draft, and speed of ships transiting the river will impact the condition of the river's current banks.

For example, a Corps' study found that as much as 24 percent of the total erosion at one Puget Island disposal site was linked to ship wakes, which it termed "insignificant." A ship with a 43 foot draft -- one that sits 43 foot deep in the water -- would generate a wake about 10 percent larger than the same ship drawing 40 feet, provided the ships were traveling at the same speed. The Corps' Final Environmental Impact Statement (EIS) explains that while both ship size and speed contribute to the height of wakes, ship speed is the greater factor of the two.

The Corps predicts that the intense competition between shipping lines will cause carriers to move toward faster vessels with more carrying capacity, but has difficulty articulating what this means: The Corps first says that the impacts of larger wakes would be "partially offset by a reduction in the total number of ships transiting the river," but offers no conclusive proof that fewer ships would be using the river. Elsewhere in the Final EIS, the Corps states that it anticipates an increase in the number of vessels with deeper drafts on the river, based on data from previous channel deepening projects. The Corps states both that there is no expected shift in the type or size of vessels and that larger vessels are expected. If larger vessels are in fact expected, the Corps should assess the impacts of wake erosion caused by the increased size of vessels and weigh those risks before the project begins.

Blasting

In order to reach the new channel depth, the Corps must remove bedrock from the bottom of the channel. The removal of an estimated 670,000 cubic yards of rock will require mechanical and explosive excavation techniques in three locations in the Columbia, and two areas in the Willamette. The blasting would take place from November 1 to February 28 in the Columbia and the remainder of the year in the Willamette.

The Corps' Final Environmental Impact Statement (Final EIS) acknowledges the potential harm that blasting may cause salmon, sturgeon, smelt, and other fish as well as the benthic organisms upon which they feed, by causing mechanical damage to their internal organs. The document first states that consequences to the benthic organisms are unknown. It also states that benthic organisms in the blast area will be completely destroyed.

By acknowledging the potential for detrimental impacts from the proposed work, the Corps is required by law to define both the geographical extent of the blasting area and the expected population size of killed benthic organisms, but it does not. Furthermore, the Corps does not provide a scientifically supported estimation of the time until complete repopulation would occur, the impact on salmon if their food source is destroyed -- if only temporarily -- and the cumulative impacts on habitat from the blasting.

Even though the Corps acknowledges that the blasting schedule conflicts with steelhead migration and would have to be changed in light of the recent listing of that species, it has not provided a specific timetable upon which to base its findings. The Corps intends to "scare fish away prior to the blast."

Entrainment

When fish are sucked up into the dredging equipment, it is called entrainment. During the channel deepening project, crab, shellfish, and fish, particularly Columbia River smelt (eulachon), risk entrainment during dredging operations. Even migratory fish that spend only a portion of their lives in the river do not escape risk, because the Corps plans to dredge continuously for two years, regardless of so-called timing windows established by state natural resource agencies for dredging activities to protect those fish.

While the Corps claims that no salmon would be entrained during dredging operations, its own studies show that adult and juvenile smelt, juvenile salmon, and juvenile sturgeon are susceptible to entrainment, especially in areas where the channel is constricted. Some fish species, such as sturgeon, can be attracted to dredging operations because of the stirred up organic matter and benthic invertebrates which make up their food.

For threatened and endangered fish species, the impact of reducing the populations of juveniles on the remaining populations of fish can be significant. However, the Corps Final Environmental Impact Statement (EIS) does not cite any scientific literature on entrainment of such species, other estuarine and riverine populations (e.g., shrimp, razor clams, and Pacific sandlaces, etc.,) or the indirect effect on fish and mammals that feed upon these species. Since these populations play a key role in the food web, their harm could have serious repercussions on the survival of both endangered and other area species.

Caspian Tern Predation on Juvenile Salmon at Rice Island.

Rice Island, a 230-acre disposal site for dredged sediments created by the Corps, is home to the largest population of Caspian Terns in the world, nearly three fourths of the West Coast's population. The 8,000 breeding pairs that migrate each year from South America have been consuming between 10 and 23 million of the 100 million out-migrating salmon smolts while in residence, though scientists estimate that 90% of those smolts are hatchery fish that do not fall under the protection of the Endangered Species Act. The Rice Island tern population has increased 600% since the mid-1980's as human development and other factors removed alternative coastal breeding habitat. The terns remain protected under state endangered species statutes.

In trying to protect the migrating salmon smolts, the Army Corps of Engineers began a project to move the population of terns about 15 miles down river to East Sand Island where their diet would shift from primarily salmon to a wider variety of ocean fish. However, the Corps' relocation efforts were halted by the Seattle Audubon Society and other organizations that believed it was wrong to make one species pay for the problems of another, especially when those problems originated from human activity. The Audubon Society, which stopped the Corps' relocation practices, would like to see a environmental-impact study done before any action is taken. Despite the halt to relocation efforts, a large percentage of the tern colony moved to East Sand Island. Roughly 1,000 remained at Rice Island and may return next year to feed off more salmon.

"Terns don't like vegetation where they nest and a dredge spoil island is perfect for that. If the Corps stopped dumping there, vegetation would grow and there'd be no more nest." -Al Clark, wildlife biologist, NMFS

Rice Island has been a disposal site since the 1960's and is one of the main proposed disposal sites for the Channel Deepening project. Despite the conflict over the terns, the Corps asserts that "removing Rice Island from consideration [for spoils disposal] is neither practicable nor necessary," in a response to the Northwest Power Planning Council. Current plans include disposing of over 5 million cubic yards of sediment on Rice Island over the next 20 years. If tern relocation efforts are to continue, there is no contingency plan included in the Final EIS to address the likely possibility that efforts to decrease Caspian tern predation will be unsuccessful or only partially successful. Nor does the Final EIS assess the impacts that relocating the tern colony would have on other salmon recovery efforts.

Regardless of its practicality, the necessity of removing Rice Island from consideration for spoils disposal must be addressed by the FEIS. If this very significant impact of the project and of the cumulative effect of past dredging is dismissed with a simple wave of the hand, clearly the analysis has not been done and the FEIS fails to meet the legal standard. It is unacceptable for the FEIS to avoid a hard look at this issue simply by assuming that other working groups will solve the problem.

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