By Josh Margolis
HAVRE, Mont. (NMB) – As the water level at Fresno Reservoir continues to drop, the Bureau of Reclamation has told New Media Broadcasters that they will have the majority of irrigation work halted next week.
Steve Davies, Area Manager of the Bureau of Reclamation’s Montana Office, says all irrigators except for those on the Fort Belknap Reservation will be cut off next week.
“Irrigation deliveries are currently scheduled to be shut off next week. There will be essentially no irrigation, though a little bit of it will trail into August because of the travel times between Fresno and Glasgow. But everybody is shutting off within the next two weeks. And releases from Fresno will be reduced from current releases of around 700 cubic feet per second (cfs) down to 100 (cfs). And the rest of the storage in Fresno will be for the Fort Belknap Indian Irrigation project as a senior water rights holder, and making sure that we have sufficient water supplies for the municipalities, the Havre Chinook and Harlem communities, for the remainder of the year and through the winter season until next year.”
Davies says this will also lead to the reduction of Milk River flows beginning next week.
As for irrigators, Davies says they will face significant harm from the lack of a water supply in the coming weeks.
“They are taking away half their water supply for the entire year. That is going to severely impact the irrigators on the entire project. They are going to have reduced crop yields as a result of this. And they are not going to have any more irrigation for the rest of the season.”
Since the collapse of Drop 5 of the St. Mary Canal and Conveyance Works System back in May halted the flow of water from the St. Mary to the Milk River, Fresno Reservoir has received little to no new inflow, while outflow has continued at a high rate.
The reservoir is currently 16 feet below full pool (full pool is 2,575 elevation or 91,746 acre feet), and is now projected to be as much as 27 feet below full pool (around 15,000 acre feet) by late August or early September.
This would represent a similar pool level as was experienced in the summer of 2017 (the lowest Fresno dropped to was 2,545 elevation, or 11,920 acre feet, on August 10th), but it would be for a more extended period of time.
“We’ve gone through a couple of these different cycles in the past. There’s a lot of unknowns at this time,” says Montana Fish, Wildlife and Parks Fisheries Biologist Cody Nagel. “In terms of what kind of precipitation we’re going to get at this time…There’s just a lot of unknowns. Any rain event in the next couple of months would be welcomed with open arms.”
Any period where the reservoir is more than 20 feet below full pool has the potential to cause serious damage to the fishery and would also make recreation more difficult.
“I believe that the one boat ramp that should still be usable at that pool elevation…would be the main boat ramp by the dam,” Nagel says. “Most of the other ramps at that pool elevation are pretty much exposed and impossible to launch a boat at…There would still be all that opportunity to fish, swim and enjoy the waters. It does tend to become a little more silty and muddy as that water goes down.”
While the water level at Fresno has continued to drop, Nelson Reservoir, located further downstream, remains less than two feet under full pool.
“It gets into the location of it. Almost all of the irrigation occurs upstream of Nelson,” says Davies. “So you have the majority of irrigation taking place there and all of the municipalities taking the water upstream of Nelson. So it gets into timing. There’s a couple weeks of travel time by the time it gets all the way down there. So Nelson is only able to provide irrigation for about 1/3 of the Malta Irrigation District and the Glasgow Irrigation at the end of the project. That plays into a large part about why Nelson is able to be maintained at a higher elevation than Fresno. Fresno unfortunately is the primary valve for the system.”
Once the repairs on the St. Mary System are completed, which is expected to be in late September or October, water will be able to flow back into Fresno Reservoir, weather permitting.
However, Davies says it will take at least 10 days for water from the St. Mary System to reach Fresno, and it wouldn’t be enough water to bring the Reservoir back to near full pool.
“It might bring it up several feet if we were able to go to full canal capacity. That equals about 600 cfs, that’s about 1,200 acre feet. There’s some losses, so we might gain between 800 to 1,000 acre feet a day. And right now, we’re projecting to go down to about (15,000 acre feet). And full pool is 91,000 acre feet…Optimistically, we’re hopeful just to be able to move water at all. But we won’t be able to fill up the reservoir.”
Stay tuned to New Media Broadcasters in the coming days and weeks for updates on this developing situation.
This story has been updated after receiving clarification from the Bureau of Reclamation. Fresno Reservoir is projected to reach a low elevation of 2,548 feet (27 feet below full pool), which is 15,000 acre feet.
