Chinook, Harlem and Havre asking residents to conserve water

The cities of Chinook, Harlem and Havre are asking residents to voluntarily reduce lawn irrigation to conserve water while the St. Mary Diversion and Conveyance Works are repaired.

"Following the recent conditions of the siphons at the St. Mary Diversion, the Havre, Chinook, and Harlem communities have been working with Montana Rural Water to find ways to conserve water along the Milk River," Havre Public Works Director Trevor Mork said in a release this morning. "With our available water supply being reduced and the continued drought in our area, we are asking Havre users to voluntarily practice responsible water conservation in regards to lawn irrigation.

"The City of Havre Parks and Recreation Department reduced watering to 30 percent throughout the city parks and (Montana State University)- Northern has reduced watering with city water and is relying more on their wells for grass irrigation.

The St. Mary Diversion and Conveyance Works, part of the irrigation System Milk River Project, that supplies much of the water in the Milk River each year suffered catastrophic failure June 17 when two of the 9-foot-tall siphons that are part of the system that transports water 29 miles from the St. Mary River to the North Fork of the Milk River breached. The system has been shut down since then.

U.S. Bureau of Reclamation said July 9 that fully replacing the siphons that failed at the St. Mary Canal, along with replacing the Halls Coulee Siphon, which is at risk of failure, was determined to be the best option.

Reclamation authorized an "emergency extraordinary maintenance" determination that allows it to expedite repairs of both sets of siphons.

Reclamation and users of the system - project beneficiaries - will share the total cost of replacement of both sets of siphons, estimated at about $70 million.

Reclamation secured initial federal funds to begin work, and the Montana government made available about $32 million set aside for St. Mary rehabilitation by the Legislature fro the Milk River Joint Board of Control to begin work on the siphon project.

The replacement is expected to take into late summer or early fall of next year.

With the St. Mary Diversion shut down, the three communities that use the Milk River as the source of city drinking water - Chinook, Harlem and Havre - have asked people to try to voluntarily reduce their water usage to extend the supply available.

The Havre Public Works press release said a local resource available to learn more about water conservation methods for lawn irrigation is the "MSU Extension: Maintaining Successful Lawns in Montana." In summary, the guide suggests watering grass in the early morning to reduce evaporation and allow the water to go deeper on an infrequent basis, typically 1 to 3 times per week. Higher mowing heights will also help to conserve water by reducing evaporation, especially during hot spells.

With the Health Advisory still in effect, the City of Havre must complete the drinking water system flush to rescind the advisory. In the discussions about the current water supply situation and required flushing, DEQ has estimated the remaining flushing to be about 1 to 1.5 million gallons over 3 to 5 weeks.

As a note, the daily average use for lawn irrigation in the Havre community is about 1.5 million gallons daily. The flushing is for the health and safety of drinking water users in addition to the overall health of the drinking water system.

For a brief update on the St Mary Diversion situation, starting now through the summer of 2025, it is suspected to have reduced water supply in the Milk River basin while the repairs are completed.

"Again, we ask our users to voluntarily practice responsible water conservation in lawn irrigation to ensure a steady water supply for drinking, fire suppression and health and sanitation purposes along the Milk River," Mork said in his release. "By all of us applying these water conservation measures, we can create a larger impact in maintaining our water supply."