ExternalitiesCosts of Preserving the Snake Dams
Another pending issue is the problem of silt piling up behind Lower Granite Reservoir in Lewiston, Idaho. The levees around Lewiston were built by the Army Corps to prevent flooding, providing 5 feet of freeboard (overtopping safeguard). But they underestimated how high they'd need to build the levees. Now the sediment is piling up and the Army Corps could flood the city if corrective action isn’t taken. The levee freeboard was last measured at 1.5 feet.
Steve Hawley, author of Recovering a Lost River: Removing Dams, Rewilding Salmon, Revitalizing Communities
says the Corps would need to remove 50,000 dump truck loads of dirt to prevent the silt buildup on an annual basis. The Army Corps estimates that it will cost $2.7 million to $36 million a year to dredge the channel and avoid the cost of building up the levees ($95 million). Who's going to pay for that?
Jim Kluss, a Lewiston City Council member and business owner, says he is no fan of taking out the lower Snake dams, but he notes, "the vast majority of the people here don't know what's going on with the levees."
"The choice we have now is dredging, raising the levees or tearing out the dams," Kluss told Hawley. "And I can tell you, there's little to no support around here for raising the levees. We'll see what happens with the dredging. If that doesn't come to pass, you might see a lot of folks around here start linking up behind dam removal." Expenditures – Salmon Habitat and Hatcheries
The BPA salmon recovery strategy is more about renovating tributary habitat than seriously dealing with the mainstem migration corridor. Currently millions of dollars are being spent to improve habitat. Reconnecting small tributary streams to larger ones, adding water to dry streams and riparian planting and fencing will all contribute to the overall health of the salmon environment but it will not allow salmon to attain viability or recover the populations.
Hatcheries were built to compensate for salmon and steelhead mortality caused by the Lower Snake River Dams. They receive about $25 million per year in BPA funds. Congress passed legislation in early1980s requiring the federal government replace lost fishing opportunity. The mitigation goals for hatchery fish have yet to be met. As salmon begin to recover - after Lower Snake Dam removal - hatchery spending could be reduced.