Climate change expected to increase Snake River sediment tenfold

Idaho StatesmanMarch 29, 2013 

The Army Corps of Engineer under law is supposed to maintain the lower Snake River navigation channel at 14 feet deep and 250 feet wide. In the draft EIS, the Corps is proposing a long-term plan to manage, and prevent if possible, river sediment deposition behind all four dams, Ice Harbor, Lower Monumental, Little Goose, and Lower Granite Locks and Dams.

As I reported earlier, groups who seek removal of the four lower Snake Dams are using this process to push their point that not only is their idea better for salmon but also better for the region’s economy. That issue has hung more on the power production from the dams than the ports, which have always been highly subsidized.

The latest proof is an excellent story by Forbes reporter Christopher Helman, “On The Mississippi, An Industry Is Floating On Taxpayer Money.” He calls the barge companies and their customers beneficiaries of “corporate welfare,” which is just as applicable for the Snake River as it is for the Mississippi.

“Washington picks up more of the cost of riverborne shipping than any other type of logistics enterprise in the U.S. except, perhaps, resupplying the International Space Station,” Helman writes.

When the Idaho Statesman wrote its historic editorials in 1997 calling for the breaching of the four dams, it pointed to these subsidies and others as part of the reason breaching added up to a net gain for the Idaho and Pacific Northwest economy. The Corps economists in 2000 disagreed saying the four dams’ benefits outweighed their costs.

It did no such analysis for the dredging EIS.

The National Environmental Policy Act that requires major government projects to assess environment and economc impacts get a lot of heat these days but the Corps process is forcing the agency to make it case after looking at all of the impacts. Just to put it into perspective, the Bureau of Reclamation’s environmental impact statement for the Teton Dam was 19 pages.

And we all know what happened there.

The Corps plan looks at several alternatives but the preferred alternative inevitably is to dredge the channel for the first time since 1995. It bases its case on sedimentation estimates from the past.

Environmentalists trying to make their case to return a place or ecosystem to a pristine past before humans are making a bankrupt argument in the face of climate change since conditions are changing so much and we can’t go back. The Corps appears to be facing the same kind of issue.

Beyond dredging, the Corps hopes that through a series of management projects throughout the watershed it can reduce the amount of sediment and thereby reduce the need to dredge and the overall costs. Buried deep in the report, but of course, dug out by opponents, is an appendix to the EIS from scientists William Elliot, Randy Foltz and Sue Miller of the U.S. Forest Service.

“Climate-modulated interactions among vegetation, wildfire, and hydrology suggest that sediment yields will likely increase in response to climate change. Within central Idaho, recent climate driven increases in wildfire burn severity and extent have the potential to produce sediment yields roughly 10-times greater than those observed during the 20th century,” they write.

This gives groups like Idaho Rivers United strong evidence in court if the agency ignores this data and proposes dredging anyway. But of course, what is the alternative?

Transportation Secretary Ray LaHood stood with Idaho Gov. Butch Otter last year as the Obama Administration announced an additional $3 million in federal funding, for the Port of Lewiston. That goes along with the $1.3 million in federal grant funds to for the $2.9 million dock expansion project. Right now the federal government and Idaho’s state government are in support of the dams and the Port despite the costs and the risks of even more in the future. But until an alternative emerges more attractive to both he subsidies will continue.

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