Duke, however, proposes removing only a “limited amount of sediment” and instead using what it calls “flushing flows” to wash the sediment downstream after dam removal.
“Duke respectfully requests that the (energy) commission allow Duke to proceed with its original concept of utilizing flushing flows to transport sediments downstream,” Duke’s appeal states.
The method would have short-term adverse impacts but no long-terms consequences, according to Duke’s environmental assessment of dam removal. Duke cited a dam removal approved by the energy commission in Oregon in 2004 where sediment removal was not required. There, one million cubic yards of sediment — 10 times the amount estimated behind the Dillsboro dam — was unleashed downstream, Duke’s appeal stated.
Duke said it is working with a commercial sand mining company to remove some of the sediment, making it an economically viable proposition, but does not want to be required to remove a specified quantity.
In Duke’s appeal to the energy commission, Duke claims the flushing method was developed in consultation with U.S. Fish and Wildlife and the N.C. Division of Water Quality. Both of these agencies did help with dam removal plans, but both advocate sediment dredgingas part of dam removal, according to formal filings by both agencies.
Duke has to get a separate permit from the N.C. Division of Water Quality for dam removal. That agency has partially signed off on dam removal, but not the full set of conditions (see public hearing infobox).
Counties appeal decision
Jackson and Macon counties, the town of Franklin, Western North Carolina Alliance and others filed a formal appeal to the energy commission this week over the decision to allow Dillsboro dam removal.
A coalition of Duke opponents suggested an alternative plan: turning the Dillsboro dam over to Jackson County to operate as a green power source and ponying up money for river conservation efforts.
The appeal claims that the energy commission did not give consideration to the alternative mitigation plan filed by the coalition of opponents. The energy commission instead gave deference to the mitigation package Duke developed in collaboration with a coalition of its own — from fishermen and paddling groups to local officials totate and federal environmental agencies.
The alternative mitigation plan developed by opponents also includes elected leaders, however, representing more than 60,000 residents. But the energy commission dismissed the alternative mitigation plan partly because it was not endorsed by Duke Power. The appeal by Jackson and Macon counties claims the energy commission gave Duke “super-party” ruling.
“The super-party ruling is extraordinarily pernicious policy as it elevates the (utility) to a preferred status with the power to veto any alternative settlement offers,” the appeal states. The energy commission is required to give “equal consideration” to various interests and not give a utility veto power over competing views if it refuses to endorse an alternative mitigation plan.
Why remove the dam?
Tearing down the 100-year-old Dillsboro dam will count as mitigation for 10 other dams Duke operates on various rivers in WNC, from the large Nantahala Lake and Lake Glenville dams to small dams on the Little Tennessee and Oconaluftee rivers. Duke’s permits to operate the dams are up for renewal. In order to get new permits, Duke has to provide environmental and recreational compensation to the public in return for manipulating the region’s rivers for its hydropower operations. The centerpiece of the mitigation is tearing down the aging Dillsboro dam.