HELENA — Water levels at Canyon Ferry Reservoir are slowly starting to rise after one of the lowest pools in recent memory this spring due to the perfect “nonstorm.”
As of Thursday, the reservoir was storing 1.39 million acre feet of water, which is about 498,451 acre feet less than what’s considered the full capacity of about 1.8 million acre feet. According to information from the Bureau of Reclamation’s website, the average amount typically stored at Canyon Ferry on May 15 is about 1.5 million acre feet.
The reservoir usually begins filling in April, after Bureau of Reclamation officials have lowered water levels in anticipation of spring runoff and rains. However, the unseasonable lack of precipitation coupled with a late runoff meant that until Wednesday, reservoir managers had been releasing more water than was coming into the reservoir.
Meanwhile, upstream irrigators also were feeling the pinch from the lack of precipitation, so they were pulling water out of the creeks that feed Canyon Ferry, according to Tim Felchle, the BOR reservation and river operations supervisor.
“This is one of those years that it seems like the spring rains haven’t helped us because there hasn’t been much since the first half of May or even April,” Felchle said. “The irrigation demands also have been really strong upstream of us.
“But we know that inflows in Toston are coming up real nice and the headwaters are starting to flow. It’s just taken awhile to offset the irrigation demands.”
He said the bureau is not keeping the water levels low so a contractor can finish up shoreline stabilization work at the Cave Point picnic shelter and on Cemetery Island. During the past three years, high water levels have eroded the shorelines there and the bureau awarded a $729,470 contract to S&K Environmental of Arlee to install riprap materials along about 1,150 feet of shoreline at the two sites.
Large rocks and logs are being installed around the shoreline, and then will be covered with vegetation like willows and natural grasses. The company is using a large barge to transport materials from the Shannon boat launch site to Cemetery Island.
“They wanted the elevation to be about 3,783 or 3,784, which coincided with their operations,” Felchle said. “They wanted us to hold it down there. We said that would be the low point, but they better hurry up and get the work done. Luckily for them, the inflows stayed low so they could do their work on the dry; they would have to do it in the wet if the reservoir went up.
“So they were being accommodated but we weren’t necessarily drawing the reservoir down for that work to be done. I thought it was going to come up in April but fortunately for them it continued to drop.”
As of Thursday, the water elevation was at 3,781 feet and needs to rise about 15 feet to be considered full.
The low water levels have made it a bit tricky for people to launch boats at some of the ramps. Shannon isn’t being closed due to the construction — although it has been off-limits to the public at certain times, like when the contractor is operating heavy equipment — but the end of the ramp sits at an elevation of 3,783, making it a couple inches out of the water.
“It could be difficult trying to launch a heavy boat off that ramp,” said Shawn Bryant, the assistant reservoir manager.
He noted that for a small fee, people can still launch boats at the northern end of the reservoir at Kim’s and Yacht Basin marinas.
Maryann Axtman, who operates Kim’s Marina with her husband, said they’ve been able to launch smaller boats and pontoons, but with the low flows, larger boats and those with long keels should probably try Yacht Basin. Two docks that were pushed up by ice over the winter like an inverted “V” will remain that way, she added, until the water level increases.
Bryant adds that launching boats on the south end of the reservoir should be fairly easy.
“Usually, even when the water is low Goose Bay’s ramp is in the water,” he said. “Silos is about the same as Goose Bay, sitting at 3,775 at the end of the ramp. Yacht Basin on this end is probably the deepest water ramp.”