Groups Says Snake River
by Jayson Jacoby
An environmental group based in La Grande wants Idaho Power Company to dig up hundreds of tons of dirt, sand and gravel, possibly from Brownlee Reservoir, and dump the debris into the Snake River below Hells Canyon Dam to rebuild eroded beaches, sandbars and fish-spawning sites.
The Hells Canyon Preservation Council contends that the reservoirs behind three Idaho Power hydroelectric dams -- Brownlee, Oxbow and Hells Canyon -- trap sediment that used to flow down the river and replenish downstream sandbars.
Mike Medberry, the Preservation Council's executive director, said he wants the Federal Energy Regulatory Commission (FERC) to require the power company to add sediment to the Snake River below Hells Canyon Dam.
FERC is the agency to which Idaho Power has applied for a new license to continue operating Hells Canyon, Oxbow and Brownlee dams.
"We're proposing a test in which they would add some sand each year for three years, then monitor the effects for five years," Medberry said. "Those are just ideas at this point, but I hope they will be looked at." Idaho Power officials, however, contend the Preservation Council's proposal not only would fail to fix any problems in the Snake River, but that the project might damage existing gravel beds where endangered steelhead and salmon spawn.
Sediment samples the company has dug from the bottom of Brownlee Reservoir consist not of sand but mainly of silts and clays -- fine-grained stuff that would wash down the Snake River rather than stick on, and add to, existing beaches and sandbars, said Craig Jones, who manages Idaho Power's FERC relicensing effort.
"If there are opportunities to improve beaches downstream from Hells Canyon Dam, then Idaho Power is interested in having those discussions," Jones said. "But dredging sediment from Brownlee Reservoir at best is not going to do anything, and at worst could degrade spawning habitat."
Medberry admits that it's impossible to predict the effects of injecting sediment into the Snake River, and that the project could have unintended consequences.
But he believes that starving the Snake River of sediment has contributed to three problems downstream since the dams were built in the 1950s and 60s, Medberry said.
The first problem is the erosion of beaches where whitewater rafters and other boaters can camp.
According to a study of aerial photographs, the number of sand bars along the Snake River between Hells Canyon Dam and the mouth of the Salmon River declined from 110 in 1965 to 70 in 1973, and to 40 in 1990. The second is the loss of gravel beds where salmon, steelhead and other fish can lay their eggs.
The third problem, Medberry said, is that erosion has exposed Native American artifacts that previously were buried beneath sand, leaving the artifacts vulnerable to damage by the river itself, by vandals, or, unintentionally, by campers who can't find a soft beach on which to pitch their tents.
Jones, though, said Idaho Power officials dispute the contention that the company is responsible for removing sediment from the Snake River.
Jones said an Idaho Power study concluded that several Idaho tributaries, including the Payette and Boise rivers, combined to supply an estimated 87 percent of the Snake River's sand. But all of those tributaries were blocked by dams -- ones built by federal agencies or by companies other than Idaho Power -- before Idaho Power constructed Brownlee, Oxbow and Hells Canyon dams, he said.
"The sand source was cut off before Idaho Power built (the three dams)," Jones said. That's why the sediment samples from Brownlee contained almost none of the sand needed to rebuild downstream sandbars and beaches, Jones said.
But the Hells Canyon Preservation Council's proposal theorizes that Idaho Power's sediment samples from Brownlee "were not distributed over a wide enough area to accurately depict the sediment size distribution.
The conclusion that the material in (Brownlee) is not the size material needed downstream cannot be statistically proven without a much more robust and statistically valid sampling methodology."
In terms of gravel for fish-spawning, Jones said Idaho Power officials believe the Snake River below Hells Canyon Dam has sufficient spawning grounds to accommodate many more salmon and steelhead than return to that reach of the river now.
"And those gravels aren't going anywhere," he said.
Medberry acknowledges that the Hells Canyon Preservation's Council's proposal lacks specifics, such as the cost to move massive amounts of sediment, and who would pay for the work.
Medberry said he hopes Congress will divert money to the project. In addition, Idaho Power could ask its customers to voluntarily contribute a few bucks on each bill.
The written proposal that the Hells Canyon Preservation Council finished earlier this year concludes that Idaho Power could dredge sediment from Brownlee Reservoir or from Lower Granite Reservoir, which is in Southeastern Washington, downstream from Hells Canyon.
Options include building a pipeline to funnel a slurry of water and sediment from Brownlee Reservoir to the river below Hells Canyon Dam, or hauling sediment in trucks from either Brownlee or Lower Granite.
Another option, according to the Hells Canyon Preservation Council's proposal, is to pipe sediment into Oxbow Reservoir, just below Brownlee Dam, and then allow the sediment to flow naturally through both Oxbow and Hells Canyon dams.
That would require Idaho Power to modify those two dams, according to the proposal.
Medberry acknowledges that the proposal would have to surmount several obstacles besides cost.
Sediments in Brownlee Reservoir, for example, might contain excessive amounts of toxic chemicals or heavy metals such as mercury.
And dredging dirt from the reservoir might require Idaho Power to lower the water level during the spring and summer, seasons when Brownlee attracts thousands of anglers, boaters and swimmers from across the West. Those recreationists' dollars are crucial to the economies of towns such as Huntington, Richland and Halfway.
Jones said Idaho Power will continue to oppose the plan to dredge sediment from Brownlee and pour it into the Snake River below Hells Canyon Dam.
He pointed out that the Hells Canyon Preservation Council was not the first organization to allege that Idaho Power's dams had starved the Snake River of sediment.
Officials from the U.S. Forest Service and Bureau of Land Management also mentioned the sediment situation when they submitted written comments to FERC in response to Idaho Power's application for a new license.
Jones said he doubts FERC would mandate Idaho Power undertake a "potentially very costly project for no benefit."
"It's not, in our estimation, a responsible use of resources," he said. "Strange things sometimes happen in relicensing that may not be based on evidence or common sense. But in my view (the sediment proposal) is too far beyond the pale of what would be a reasonable measure for relicensing."
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