Hot, dry weather + failed infrastructure = Water Woes for Blaine County and the Hi-Line
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Steve Edwards
Crews with Pike Construction were busy at this site on the south side of Highway 2, two miles west of Harlem, removing an old culvert that ran under the Harlem Irrigation Canal. The canal, which runs along the south side of the highway, was breached when a culvert failed, shutting down water to about 11,000 acres of land while the break was repaired.
During the past two weeks, with unusually prolonged, hot temperatures, there have been a couple of infrastructure failures that caused water woes in Blaine County. The St. Mary Diversion is part of a system that moves water that ultimately ends up in the Milk River. About two weeks ago a small leak was discovered in one of two siphons in that system. Bureau of Reclamation officials are monitoring the leak and are hopeful repairs can be postponed until later in the year.
Last week, a break in an irrigation canal providing water for 11,000 acres in the eastern part of the county threatened crops at a critical time of the growing season. That break required immediate repairs that should soon be completed, allowing irrigators to resume using water.
Leak at St. Mary Diversion
being closely monitored
About ten days ago Bureau of Reclamation workers discovered a leak in one of two siphons that make up part of the 29-mile system of dams, dikes and siphons that transfers water from the St. Mary River to the Milk River. The water ultimately goes to valley irrigators and supplies drinking water to several municipalities including parts of Havre, Chinook, Harlem, Fort Belknap and Dodson.
Jennifer Patrick, Milk River Joint Board of Control Manager, said by phone last Thursday, "The leak is being monitored. The concern is not so much about the leak, which seems to be stable, but rather the higher than normal amount of water we are drawing from Fresno (a holding reservoir west of Havre) to meet demands of irrigators and municipalities."
At the last Joint Board of Control meeting the group approved starting the annual shutdown of irrigation water from Fresno on August 3. Patrick added, "That will effectively end irrigation water to users for this season about August 10 or 11." Due to declining water levels, this year's shut down of irrigation is earlier than usual.
The Joint Board of Control is made up of stakeholders with interests in water from the Milk River including the eight irrigation districts and municipalities, listed earlier, that use water from the river. Patrick added, "Under our Municipality, Business and Industry contract we are mandated to release at least 40 cfs (cfs=cubic feet of water per second, that is about 300 gallons per second) for users other than irrigators-mainly the cities that rely on the Milk River for their drinking water. We release 45 cfs to assure we are meeting our requirements."
Patrick added, "Right now Fresno is at about 45,000-acre feet. To assure there is adequate water under the described contract, the minimum amount of water needed is 8,000-acre feet. The amount of water currently being withdrawn is outpacing the amount coming into Fresno. If the leak at the siphon were to worsen and the hot weather continue or worsen, the gap between water being drawn from Fresno and that being replenished would widen. That could complicate things greatly."
If water supplies began to diminish more rapidly from Fresno, even after shutting down the water for irrigation as planned, there could be water restrictions in the towns to avoid more serious water shortages. One former irrigation board member who was familiar with water levels at Fresno and the resulting availability to local towns, said, "There could be water restrictions, such as no watering of lawns, and the total water available to each town would be at a lower level, more like winter levels than summer levels when additional water is required."
On a more positive note, Patrick concluded, "The Bureau of Reclamation people, who are monitoring the leak and will eventually complete or oversee the repairs, feel the leak is not worsening at this point. They also believe they have a way to stop water flow through the siphon tube that is leaking so it could be repaired." In that scenario, lesser amounts of water would still be coming in to Fresno. "Hopefully," Patrick added, "We don't end up in that situation for making repairs."
Breach in the canal providing water to the Harlem Irrigation District
Last spring, two miles west of Harlem along Highway 2, the Montana Department of Transportation (MDT) installed a three-foot diameter pipe inside an existing four-foot diameter culvert which was showing signs of potential collapse. The existing culvert runs south from an area south of the BNSF rail bed, under Highway 2, under the borrow pit by the highway and, finally, under the Harlem Irrigation District's canal that runs parallel to Highway 2 in the area. The water from that culvert eventually is discharged into a ditch running to the Milk River.
MDT officials felt the three-foot diameter pipe, of a newer, smooth type, would carry the same volume of water as the old, four-foot pipe that was corrugated. MDT personnel also felt the addition of the inner pipe into the old pipe was a simpler and quicker fix than completely replacing the old culvert.
At the time, Harlem Irrigation District board members registered their concerns about the method of repair. Ralph Snider, board president, said, "I felt at the time that the space between the new and old pipe could be a source of collapse if the old pipe deterioration worsened." The breach occurred when the old pipe, under the canal, failed, allowing the bottom of the dirt canal to wash away. The irrigation water ran out the failed spot and was lost, shutting down the canal's ability to provide water.
Steve Edwards
Last week Pike Construction crews were digging out the old culvert, at the site of the break, and repacking soil to secure the newer, smaller culvert that had been installed in the spring. Jeff Sather, a member of the Harlem Irrigation Board, was at the site and said, "While the break affected about 70% of the 11,000 acres that are irrigated in our district, we had to shut down the entire district while the canal is fixed. We can't charge the canal with the break in it."
The cost of removing of the old culvert and stabilizing the canal is being borne by the MDT. Repair costs are typically the responsibility of the irrigation districts affected. Sather said, "The district appreciates the MDT covering the cost of the repairs. Unfortunately, there's no way to calculate the loss in crop value during such a critical time of the growing season." John Pike, whose company is doing the repairs, said he thought the repair to the canal would be completed in just a few days.
With no immediate prospects for relief from the hot and dry weather we are experiencing, hopefully there will be no more surprises that cause more water woes in our area.
