Defenders of Wildlife take aim at Corps plan for Yellowstone River, fish
GLENDIVE, Mont.--The final environmental impact study may be out, but the last word on the Glendive Intake Diversion dam is still being had. Defenders of Wildlife have come out swinging against the final draft of an environmental study that looks...
GLENDIVE, Mont.-The final environmental impact study may be out, but the last word on the Glendive Intake Diversion dam is still being had.
Defenders of Wildlife have come out swinging against the final draft of an environmental study that looks at ways to make the weir more fish friendly, saying it represents "wishful thinking" rather than sound science.
"To argue that an artificially manufactured bypass has an equal likelihood of success as a free-flowing river is the typical hubris of the Corps of Engineers and the Bureau of Reclamation, who always think that they can do better than nature," Defenders write. "The clear solution is to remove the old rock weir dam, open up the Yellowstone River and install irrigation pumps. Fish passage will improve, irrigators and farms can receive water through pumps and generations of Americans will benefit from a free-flowing Yellowstone River."
The Intake Diversion Dam serves 58,000 acres of cropland in North Dakota and Montana. Making it more fish friendly became a subject of study after the pallid sturgeon was listed as endangered in 1990.
The fish bypass channel, which the Bureau of Reclamation and U.S. Army Corps of Engineers have chosen as preferred, would cost $57 million to construct and about $156,000 to maintain annually. A concrete weir would be built to replace the existing wooden weir. The new structure would include a fish notch that closely mimics conditions the fish have been observed to use. To accommodate the fish notch, the concrete weir would be a foot or so higher than the existing wooden framework, however, its height would actually be less than the final height of the present weir once boulders have been placed on top of it.
The boulders are not a smooth surface and can catch fish trying to go over the top of the dam, and also periodically rise slightly above the water level late in the season. The concrete weir, meanwhile, would be smooth, and unlike the boulders, would be submerged year-round.
The pumping option Defenders want instead would cost $138 million to install and $2.3 million annually to maintain, according to figures developed by the U.S. Army Corps of Engineers and Bureau of Reclamation. Adding renewables to that system bumps the installation cost up to $478 million, with annual maintenance costs of $1.924 million.
Defenders of Wildlife have disputed those figures, saying they are too high and contain too many contingencies against interruptions. The final draft of the environmental study responds to those claims, going into detail on how the numbers were arrived at, as well as explaining the choices made for contingencies.
In addition to ignoring the substantially increased costs for water pumps, Lower Yellowstone Irrigation Project manager Brower says Defenders are also ignoring substantial environmental downsides that would come with electrical pumps.
Among these, electrical pumps would generate about 11 million pounds of carbon pollution, even if the project is able to consistently provide 15 percent renewable energy, he said. The pumps would also invade wetlands and wildlife habitat.
"Noise pollution from the pumps will interfere with whooping crane feeding areas and more importantly, the northern long-eared bat, which uses echolocation to find food and fly," Brower said.
Another downside to pumps that Brower pointed out is they would require periodic dredging of the river, which has been shown in studies to be bad for many aquatic species, and the banks of the river would need to be rip-rapped to prevent channel migrations in areas where pumps are located.
Rip-rapping has been shown in studies to increase the velocity of the river and deepen its channel. The state has begun a program recently to reward landowners who choose not to rip-rap the Yellowstone and allow it to migrate more naturally, called channel migration easements.
Removing the dam would lower the river's water level 7 or 8 feet, drying up at least two natural side channels, which have been shown in other studies to support a diversity of aquatic life. That lowering would also render inoperable a couple of smaller, private pumping stations that have water rights along the river, according to Brower.
"They are quick to point out a few theoretical deficiencies with the fish passage, but they are turning a blind eye to known environmental problems the electrical pumps would generate," Brower said. "And they are turning a blind eye to real science and study that has supported the fish passage in the EIS."
The final environmental study outlines how the proposed fish passage is being designed to match conditions developed by fish biologists working on recovery of the pallid sturgeon. They will mimic natural conditions the researchers have observed the fish using.
Patrick Braaten is one of those fish biologists, working with the U.S. Geological Survey the past 15 years to figure out what would help save the pallid sturgeon, a prehistoric fish placed on the endangered species list in 1990. He is very familiar with the proposed fish bypass.
"The hydraulic elements of the proposal match fairly well to what we had observed in the field design criteria that went to engineers," Braaten said. "It was designed to the depth and velocity that we observe for these fish. So we have provided conditions that should facilitate fish to migrate through."
Whether that will be enough to save the pallid sturgeon is an unknown, the Corps and Bureau acknowledge in their final draft of the EIS, but that is also true of the other alternatives. At this point no one knows if any of the pallids will migrate far enough up the Yellowstone when they spawn. That's important, because the larvae need miles and miles of river to drift down as they develop. They must get strong enough to avoid the headwaters of Lake Sakakawea, where other studies indicate an anoxic environment may be killing them.
Currently, between 12 to 26 percent of the fish are motivated enough to reach the diversion dam at Glendive - a relatively small percentage of an increasingly smaller population of wild fish, who now number between 100 and 126, according to Montana Fish Wildlife and Parks studies. Those fish do travel along the dam in ways that Braaten indicated suggest the fish would use a channel if it were there. How far they would continue to swim after that is not known.
The Corps and Bureau, in the final draft of the Environmental Impact Statement, note that all options contain uncertainties and points out the fish notch is merely one in a suite of measures being taken toward recovery of the fish. The fish notch offers a chance to quickly discern whether 258 miles is enough distance for larval drift, which has been identified as an important question for the ongoing research.
"Considerable uncertainty remains regarding the type and extent of management actions needed to meet recovery objectives," the study states. "Although providing passage at Intake has many uncertainties, the current state of the science provides no alternative that guarantees greater chances of recruitment and provides measurable benefit to the population. Thus the federal agencies charged with the responsibility to conserve the endangered and threatened species have determined, based on the best scientific data available as described in this EIS, that passage at Intake is a critical component to increasing pallid sturgeon recruitment in the Upper Basin."