Fish, Farmers, and Ft. Peck

[JoseCuervo]

Damn Dams

Five million tons of silt in the Missouri River drift by Culbertson each year.

The farmers along the river between Fort Peck Dam and the confluence with the Yellowstone River would like more of that soil to remain in place as cropland.

But their efforts have been hampered by extended drought, variable stream flows and a moratorium on stream bank stabilization, says a Wolf Point conservationist. The situation makes it difficult for the irrigation of 53,000 acres of cropland along the approximately 150 miles of river, said "Buzz" Mattelin, who heads the Roosevelt County Conservation District, which has its office in Culbertson.

The paradox is that in the short term, the erosion is eating away pump sites needed to water crops, said Bill Rathert, who owns land on the south bank of the river opposite Frazer, about 15 miles downstream from the dam.

In the long term, Rathert said, farmers fear the release of large amounts of water to replicate the high spring flows of a free-flowing river to aid fish and wildlife along the entire river to its confluence with the Mississippi.

That won't happen anytime soon, as the current crisis on the river is that the pool behind Fort Peck Dam is at a record low.

A recent increased flow from the dam, to assist downstream fish spawning and barge traffic, will end May 27. The release from the dam went from 6,000 to 7,000 cubic feet per second to 11,000 cfs. It will return to 9,000 cfs next week.

It is fluctuation and the level of the water under the ice in winter that is eating away the banks of the river and isolating irrigation pump sites, Rathert said.

A photo provided by Rathert demonstrates the loss of riverbank in the past two years. A pump site in the photo was eaten away, he said.

Rathert said that in the past 15 years he has probably lost 100 acres to erosion. He presently irrigates 215 acres of feed barley and alfalfa.

Mattelin said after the drought of the 1980s, water users considered what might be done to stabilize the river bank.

The Natural Resources Conservation Service had studied the process of how the ebb and flow of the river reaches equilibrium, he said.

In the normal meandering of a river over time, the loss in one place is offset by a gain in another, Mattelin said. However, since the river was dammed at Fort Peck in the late 1930s, about 3,000 acres of land has been lost to erosion. The Army Corps of Engineers estimates it will take another 40 to 45 years before the river regains its natural equilibrium, he said.

Mattelin said that while Rathert has his erosion and loss of a pump site, an added problem is that just downstream, the intake for the Fort Peck Irrigation District gets filled with silt, and there is a moratorium on stream bank stabilization, such as riprap.

In the longer term, irrigators fear that the Corps will be forced to manage the river so that flows ebb in the summer and surge in the spring. Environmentalists argue that such action would encourage fish spawning and bird nesting by endangered species.

According to the U.S. Fish and Wildlife Service's 2000 Biological Opinion, Fort Peck Lake would have to reach an elevation of 2,230 feet before a spring rise could be attempted. The current elevation is 2,203.7 feet and dropping daily.

The spring rise would take place once every three years, if the water conditions in the reservoir allowed. The peak discharge would range between 20,000 cfs and 25,000 cfs and persist for a minimum of three days.

According to stream flow records for the Missouri River at Wolf Point, the flow in November 1997 hit a high monthly average of 22,210 cfs. Historical records indicate it hit monthly averages of 22,280 cfs in 1976 and had back-to-back months of 26,040 and 36,270 in 1975.

Mattelin said an engineering study being completed done by the NRCS is measuring how many of the pumping sites between the dam and the confluence of the two rivers just inside the North Dakota border would be usable during a "spring rise."

He said preliminary results suggest that of the 143 sites in that stretch, 90 would have problems.

Mattelin does not consider himself a critic of the Corps of Engineers.

"They do listen," he said. "They try to keep enough water in the river to irrigate."

He said the river management is for everybody's benefit. "It is complicated," Mattelin said. "They have to strike a balance, and follow the law, too."

The paradox is complicated, also.

Mattelin said that 10 to 12 years ago, not much attention was paid to the river and its use. "Now there is too much attention," he said.

For the irrigators, the question is how to maintain the water use that provides about $25 million of direct economic impact to that 150 mile segment of the Missouri River.

 

[Nemont]

EG,
All very interesting reading but the silt situation is not from the Missouri but from the Milk River. The Milk flows into the Missouri below the dam.

Below is a pic of the confluence Milk on the left, Missouri on the right.

Just as the article points out the spring rise will not take place until the lake rises at least 30 feet from its present level. Wouldn't hold my breath for that.

Nemont

[ 05-22-2004, 18:09: Message edited by: Nemont ]