Officials tour St. Mary Diversion

BLACKFEET INDIAN RESERVATION - The massive, rusted steel pipe nestled in the foothills of the Rocky Mountains shakes from the force of the water rushing through it.

Near the top of its downhill slope, the 90-inch siphon periodically jerks because of turbulence in the water, as if a giant knuckle is tapping it. Near the bottom of the downhill slope, before the siphon crosses the St. Mary River and runs up the other side of the valley, the 80-year-old pipe sways as the water races through it. Along the length of the pipe, water hisses as high pressure forces it out of expansion joints in the siphon.

"This is every day. I can see this moving," said John Tubbs, chief of the Resource Development Bureau of the state Department of Natural Resources and Conservation.

The pipe is part of the system that about 50 people toured Thursday, a system that provides much of the water in the Milk River each year. The system, called the St. Mary Diversion, is in need of repair.

The siphon and another siphon 8 miles east show their age. Water seeps or gushes from many expansion joints, spraying 10 feet into the air at one point. Some concrete supports are cracked, others are gone and have been replaced with wooden beams to hold the pipes in place.

George Gliko, civil engineer with the federal Bureau of Reclamation, said a metal structure like the siphon typically is expected to last 50 to 60 years. The St. Mary siphon has two pipes, one 90 years old and one 80 years old.

Lt. Gov. Karl Ohs formed a working group in November to find ways to fund rebuilding the diversion. It supplies up to 70 percent of the water in the Milk River in normal years. In the drought year of 2001, it supplied more than 90 percent of the water in the river.

Before the St. Mary system of the Milk River Irrigation Project was authorized in 1902 and construction started in 1906, the Milk River dried up during most summers.

The estimated cost of repairing the diversion tops $100 million. The original authorization of the system requires that the irrigators who use the water pay for the repairs in the year they are done.

The goals of the working group include showing that other groups benefit from the diversion and that the cost should be spread among numerous users, that a federal appropriation should be made, and that the cost to users should be spread out over time.

The diversion supplies water to irrigators in the Milk River valley, to recreationalists, to the municipal water systems of Havre, Chinook and Harlem, and provides habitat for fish and wildlife.

It includes a storage dam, a diversion dam and 9 miles of canal that transports the water to the first siphon, another 20 miles of canal and a second siphon, and a series of five concrete chutes that drop the water 214 feet before releasing it into the North Fork of the Milk River. The river crosses the border into Canada, where it runs more than 200 miles before returning to Montana.

The working group has proposed legislation in Congress asking for $9.5 million to fund a study of the diversion - who benefits from it, what work is needed to repair it, what impact it has on the Blackfeet reservation, and how best to fund its repairs - and to create an emergency fund to make repairs if the system suffers a catastrophic failure before it's rebuilt.

The tour, sponsored by DNRC, the Fresno Chapter of Walleyes Unlimited and the Blackfeet Tribe, followed a monthly meeting of the working group Wednesday in Babb.

People on the tour included Ohs, members of the working group, Blackfeet tribal officials, members of the commission negotiating water compacts with Indian tribes in Montana, Milk River Valley irrigators, and other people from the Milk River valley and the Blackfeet reservation.

The tour left Babb shortly after 9 a.m. and stopped first at the dam on Swiftcurrent Creek that stores up to 68,080 acre-feet of water for the diversion. The early-morning fog cleared in time for a clear, sunny view of the lake.

Sherburne Dam and the eastern edge of Lake Sherburne are on the Blackfeet reservation, while the lake extends several miles into Glacier National Park. All other parts of the diversion are on the reservation.

The earthen dam, 107 feet tall and 1,086 feet wide, was completed in 1921. A concrete, reinforced earth addition raised the elevation of the dam in 1982, providing more flood-control ability.

Long said that in 1999 a storm with winds reaching 180 mph tore the roof off of the gatehouse and control structure, which sits in the lake connected to the dam by a walkway. The wind carried the roof over the dam, dropping it near the base of the dam.

The next stop on the tour was the confluence of Swiftcurrent and Boulder creeks. Boulder's streambed still shows the effect of a 1964 flood and other floods, with debris and rocks from rushing water littering its bed, which Long said illustrate one of the advantages of the diversion - control.

Swiftcurrent Creek, whose flow is controlled by Sherburne Dam, shows little after-effects of flooding. The stream flows peacefully over a tree-lined bed, unlike the rocky, broken bed of Boulder Creek.

Another stop in the tour was the place where the actual diversion of water begins, at a dike that sends water into the first canal.

Pieces from an old bridge that crossed the St. Mary still span part of the river over the dike.

The concrete structure that regulates the flow into the canal also shows its age, with crumbling sections in its supports and in the walkway across it.

One issue is how to deal with the bull trout, an endangered species in the St. Mary watershed that can make its way into the diversion. There they can be killed or end up in the Missouri River, where they can't compete with other aquatic species. The trout also cannot jump over the dike to reach spawning grounds upstream.

Another issue is the leakage of water from the diversion. Gliko said the system, which was designed to transmit up to 850 cubic feet per second of water but now has a maximum capacity of 670 cfs, loses about 70 cfs of water before it reaches the siphons.

The leakage provides water for crops and natural growth west of the canal, but causes problems in constructing homes and other buildings, Gliko said.

The first siphons take water from the canal and transport it across the St. Mary River on a bridge, then up the hill on the other side to release it into the next section of canal. They are about 3,200 feet long and operate using gravity. No pumps are used in the St. Mary Diversion.

Dan McCauley of Entranco prepared a study and an application for a grant from the Treasure State Endowment Program to replace the bridge upstream while keeping the delapidated 1915 historic structure that takes traffic across the river as well as holding the siphon.

"As far as we know, it's the only bridge of its type," McCauley said. "It's pretty unique."

McCauley said the bridge needs replacement, and will likely eventually collapse if traffic continues to use it.

The next stop was the canal the siphon drops the water into, with a review of the areas where the upper slope has slid into the canal because the water saturates the soil, and areas where more landslides are about to occur.

"This one we work on pretty much every year," Long said about one location.

One of the bureau's ideas for reducing slides is to build a 50- to 60-foot-high dam in the coulee the canal runs along, creating a lake that would fill the coulee for about 2 miles. That would stabilize the banks and possibly create a local fishery, Gliko said.

At the end of the canal, which transports the water over the Hudson Bay Divide, is the first of the five concrete drop structures that release the water into the Milk River.

Long said that until the bureau receives the appropriation to rebuild the diversion, the focus will be on maintaining the siphons and the chutes of the drop structures.

"If the water got under the chute, that would be really bad," Long said.