SUBLETTE COUNTY – A historic winter season of snowfall, coupled with recent warm springtime temperatures, has caused area streams and rivers to run high and breach their banks. There are several low-lying areas surrounding these water sources that have flooded with feet of water as the early snowpack runoff flushes out of Sublette County. Cooler temperatures this week – including a forecast of possible snow today – is expected to help ease streamflows, at least temporarily.
The Green River near LaBarge saw a peak of 18,000 cubic feet per second (cfs) over the weekend between Saturday evening and Sunday morning. The reading exceeds the peak of high water observed back on July 3, 2011, which was another big snow year for the region. The National Weather Service predicted a crest of 18,300 cfs (10.3 feet), which would have been the second largest flow since 1947. The river reached a depth of 10.23 feet just after 10 a.m. on Sunday, putting it into the moderate flood stage range. The record for high water at this site is 10.5 feet.
According to Jim Mitchell of Sublette County Emergency Management, cooler temperatures and area snowfall early this week will drop stream flows temporarily, before another warming trend later in the week will cause rivers to crest once again.
The New Fork River is also causing some flooding, and is currently sitting at 7.42 feet. The river crested at 7.94 feet between Saturday and Sunday, with the record water depth not too far off at 8.3 feet.
The flooding in Sublette County is also impacting smaller area streams such as Faler Creek south of Daniel Junction, where high water was slapping against the girders last Thursday on a bridge on U.S. Highway 189.
The rise in water has impacted side roads throughout the county, such as South Piney Creek Road, County Road 23-222 and BLM road 4203. According to the National Weather Service in Riverton, Whalen Road and County Road 318 near LaBarge have 2.5 feet of water flowing over them.
In addition, high water from Pine Creek in Pinedale has caused some flooding in areas such as Boyd Skinner Park, where submerged pathways meander through the park.
All tributaries and streams along the Green River Basin have crested at this time, and a slower rate of snowmelt is expected through early this week, causing streams to noticeably recede. Beginning on Wednesday, waters are expected to begin increasing in flow and will continue to rise through Friday.
According to WYDOT Resident Engineer Dan McGillivray, he hasn’t seen any flood damage to roadway structures such as bridges as of Friday, June 9. In cases where high water is high enough to run along the underside of bridges, he says the major impact is water being restricted on the upstream side. This can cause water to fan out, flooding low-lying areas in close proximity.
He says it would take a great deal of water pressure to actually lift a bridge and cause considerable damage. Right now, WYDOT is just keeping an eye on the rising water.
“If the water continues to rise, we’ll analyze it,” he said.
According to Bridger-Teton National Forest (BTNF), some local roadways have been closed off from public use due to being washed out. Roads such as South Piney Creek and Thompson Pass in the Big Piney area are currently closed, while Teepee Creek Road near Pinedale also prohibits travel at this time. In LaBarge, BTNF reported that LaBarge Road near the fish barrier is closed, while Minnie Holden Creek at Fontenelle Road is also closed.
Wyoming Game and Fish (G&F) has also temporarily closed several boat and fishing access areas due to damage to boat ramps, access roads and parking areas. G&F stated last week that these areas will remain closed off to the public until water levels drop and crews can get in to conduct repairs.
Some closures around the county include the airport access to the New Fork River and Green River access locations such as McLoughlin, Huston, Sommers, Fear Meadows and Reardon Draw.
G&F also advises people to not float the rivers until they have receded, as bridges and barbwire fences that cross these streams can be hazardous in these conditions.
Local agencies strongly advise against traveling through flooded areas on roadways, as swift currents can easily sweep away vehicles if conditions warrant.
With still a good amount of snow remaining in the mountains surrounding Sublette County, high water is expected to remain a concern.
The National Weather Service in Riverton recently extended its flood warning for the Lower New Fork River and Lower Green River until 11:45 a.m. on Thursday. They advise against any kind of recreation along both the New Fork River and Green Rivers until waters drop considerably.
According to Sublette County Emergency Management, people near any river need to be prepared to move without much notice. Mitchell suggests having a “fly-away” kit at the ready to grab if flooding causes evacuation measures. At this time, Mitchell suggests staying away from water, and for hikers, river crossings are ill advised.