One of the areas that has been prone to flooding the past the Hwy. 135 bridge over the Gunnison River near Garlic Mike’s. (Photo by Jacob Spetzler) [/caption]
If temperatures warm too quickly, the Upper Gunnison River Basin’s high snowpack could lead to flooding in some areas as the snow begins to melt.
On Monday, April 17, Gunnison County Emergency Services hosted a multi-jurisdictional meeting to discuss spring runoff and the possibility of flooding in the Gunnison Valley as temperatures rise. Although the upcoming weather forecast is favorable and no cause for alarm, local officials and law enforcement made sure plans are in place and sandbags are available in the case of rapid snowmelt.
Snowpack for the Gunnison Basin sat at approximately 160% of normal on April 9 with more snow on the way. After an exceptionally wet winter, rapid warming has the potential to overfill streams and rivers — putting low-lying areas at risk as the snow finally starts to melt away.
Temperatures above freezing overnight at higher elevations for several days can lead to expedited snowmelt, National Weather Service (NWS) Hydrologist Erin Walter said during a weather briefing at the start of the meeting. But transitioning into the middle of the week, she said the basin will see the influence of a low pressure system carrying snow and cooler temperatures.
“This downward turn in temperatures is what we want to see for snowmelt,” Walter said. “If we saw a ridge of high pressure over us and all of these temperatures climbing for a prolonged period of time, that's when we need to be on high alert.”
The weather outlook in the short-term is still favoring an uneventful melt. Walter said the NWS isn’t predicting any serious warmups through the end of April, with slightly below normal temperatures and above normal precipitation in the forecast.
Particularly at the low- and mid-elevation, the snowpack is significantly above normal for this time of year, said Colorado Basin River Forecast Center Hydrologist Ashley Nielson.
“March was wet and cold, as I’m sure everyone was aware of,” she said. “We held onto snow below 9,500 feet and also accumulated snow. That can be important in terms of high water as we move through the season. Some of the snow we maybe should have already gotten rid of is still around.”
Nielson encouraged local officials to keep an eye on the peak flow forecasts for the surrounding rivers and streams, which predicts what the maximum daily streamflow will be through the end of July. With a high snowpack, peak flow forecasts throughout the majority of the area are greater than the 90% percentile, she said. On April 17, flows at the Ohio Creek were the third highest in over 20 years and the ninth highest in 100 years at East Almont gauge.
According to Streets and Refuse Superintendent Jason Kibler, the City of Gunnison is fully staffed and has access to loaders and backhoes in case flooding occurs. Although the city and county have sandbags, Gunnison County Emergency Manager Scott Morrill encouraged residents to purchase their own at Ace Hardware, Tractor Supply and Western Lumber.
In the case of an emergency, it ensures staff have enough sandbags to protect public infrastructure such as the wastewater treatment plant and the city’s well system. Although this is second to life safety, if a landowner is having problems with high water on the property or flooding, “that’s on them,” Morrill said.
“They need to do the prep work,” he said.
Gunnison County Operations Manager Sparky Casebolt said the department has been keeping a close eye on flood-prone areas. He said staff’s number one concern is Slate Creek, which is running high and has the potential to block off access to Marble along County Road 3.
Montrose and Delta counties are experiencing minor flooding. In Gunnison County, law enforcement will begin monitoring the rivers and creeks with 24-hour coverage starting at the beginning of next week.
While some of the areas have predetermined flood stages or river gauges that can be monitored remotely, others don’t and require a closer eye, Morrill said.
“A lot of it is just going to be visual monitoring,” he said. “If we start seeing water really getting high, it's checking some of these places and making sure that we're still in good shape.”
According to Morrill, the last time Gunnison County experienced serious flooding was 1996. Areas that have been problematic in the past are the bridge on Hwy. 135 near Garlic Mike’s, the Dos Rios areas and low-lying areas in West Gunnison along the river such as the Senior Care Center.
Morrill encouraged residents who live in a floodplain, but lack flood insurance to sign up early due to a 30-day waiting period. Even if homeowners sign up this week, it will be the middle of May — and close to peak runoff — before it goes into effect, he said.
Morrill told the Times he hasn’t seen any warning signs of flooding in the immediate area yet. Recently, the weather has been warming during the day enough to start melting some of the snow, but still getting cold enough at night that it freezes.
“What we don’t want to do this early in the season is get into that 24-hour melt,” he said. “That's what really causes problems when we still have a large snowpack.”
(Bella Biondini can be contacted at 970.641.1414 or bella@gunnisontimes.com.)
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