Although there’s much to celebrate with this season’s snowpack and predicted runoff, those living near ditches, creeks and in flood-prone areas should not underestimate flood risks.
“We’re looking for a big runoff,” Bob Hurford, Division 4 water engineer with the Department of Water Resources, told a healthy-sized crowd Monday, March 20, at a State of the River meeting in Montrose. Although the meeting focused heavily on the Colorado River — which is woefully undersupplied in the face of over-demand — Hurford also directed attention to the Uncompahgre River, the Gunnison River and its North Fork.
SnoTel sites above these waterways and their reservoirs show big-time snowpack, with the gauge at Columbine Pass sitting at 262% of normal and more than 41 inches of snow water equivalent on the Uncompahgre Plateau, Montrose County Emergency Manager Scott Hawkins said Tuesday.
“And it’s going to come down,” Hurford said Monday, referring to the 41 inches. He called snowpack on the plateau “crazy,” and reminded attendees of localized flooding in 2019, another big snowpack year.
That year, the snow began melting off at the end of April — quickly — swelling Happy Canyon Creek, Spring Creek, Dry Creek and others. When Happy Canyon Creek overflowed its banks, it flooded the Heritage Estates community and other locations in Montrose County.
“We had flooding locally,” Hurford said Monday. “Don’t take this lightly. This is really serious this year.”
The county is preparing and is working on a public education campaign too, Hawkins said.
“We definitely have the potential to get a decent amount of flooding this spring,” he said. “ … We are nervous a little bit.”
He said temperatures are expected to stay below normal coming into April, but that will not help in May, which usually brings with it a rapid warmup that spurs an also-rapid runoff.
Last year, thirsty soils absorbed much of the runoff from the above-average snowpack, which meant less coming into reservoirs and natural streams. The past summer brought heavy monsoons, however, and seemingly ceaseless storms this winter have left soils much wetter.
“It’s just going to come off. We’re concerned about that. There is enough snow in the San Juan mountains right now to completely fill Ridgway Reservoir,” Hawkins said.
The information Hurford shared bears that out.
He said the Colorado River Basin Forecast Center had predicted 127,000 acre feet for Ridgway Reservoir as of Monday — the reservoir’s average is 95,000 acre feet. (An acre foot is 1 foot of water covering 1 acre of ground; visualize a foot of water covering a football field.)
The reservoir was already sitting at about 70,000 acre feet, leaving only 14,000 acre feet before it will be full “and there’s 127,000 acre feet of water sitting up there on those (mountains),” Hurford said. “It’s got to come down and it’s going to come down pretty fast.”
He said the Uncompahgre Valley Water Users Association might soon ramp up release rates to make room for the runoff.
“You will see the Uncompahgre start to fill up, especially coming through town. It’s not from stream runoff. It’s what’s coming through the reservoir and what they’re releasing to make room,” Hurford said.
Hawkins said Tuesday the UVWUA has indeed ramped up releases, taking the reservoir down to about 68,000 acre feet, with a May goal of about 60,000 acre feet.
The UVWUA’s manager was not available for comment Tuesday afternoon.
Hurford also discussed conditions in the Gunnison River Basin.
“Great snowpack this year. The other component is we had a really good monsoon season last year and we kind of had an OK one in 2022. But the years prior to that … (had) really dry soil conditions,” he said, in explaining that the basin’s biggest storage pot, Blue Mesa Reservoir, did not fill despite the better snowpack and inflow in 2022, because of how dry the soil was.
The Colorado River Forecast Center predicted 810,000 acre feet for Blue Mesa this season, a prediction Hurford termed “a little generous” despite better soil conditions. “But it’s still great news and it’s really good for water supply conditions,” he said.
Hydrological conditions this year are categorized as “average wet.” Hurford does not expect Blue Mesa to fill all the way, but is estimating 150,000 acre feet more than what was predicted at the end of January.
Peak flow targets for the Lower Gunnison this spring are expected to be maintained at 14,000 cubic feet per second over two days, then half-bankful flow of 8,000 cfs for 20 days.
“That’s a lot of water, folks,” Hurford said.
Paonia Reservoir is predicted at 167,000 acre feet. It typically fills at about 81,000 acre feet. “That’s double. This is big. Paonia Reservoir will fill and spill any year, even a bad year. There will be a lot of water coming down through there,” Hurford said.
In Montrose County, efforts are underway to open a sandbag distribution site, Hawkins said. The exact details are being worked out, he said, but the county intends to fill and have available sandbags that people can pick up for no charge. The county also wants landowners to keep ditches free from debris, to the extent it is possible.
Hawkins said the county is eyeing Happy Canyon Creek, which as a natural drainage is managed by the Army Corps of Engineers. The county is also looking at Spring Creek, the Uncompahgre, Cimarron Creek an Silverjack Reservoir. “Silverjack will spill,” Hawkins predicted.
“The Gunnison River Basin is not at record high, but it’s high,” he said. “I think there’s a lot of concern for Delta. Delta’s going to get it worse than we are.”
Hawkins’ department met recently with Hurford, water commissioner Scott King, Montrose County Road and Bridge Department, county commissioners and the Montrose County Sheriff’s Office to discuss the runoff situation.
“We need the water,” Hawkins said, giving nod to “impressive” readings on SnoTel gauges and noting localized flooding has already occurred in the region, including Dolores, in Montezuma County.
“There’s a lot of snow in the Southwest corner of the state. Our snowpacks are record high in some areas,” Hawkins said. “A quick spring warmup could cause potential flooding.”
