Flooding starts; more comingJun 4, 2017 From staff reports
An official flood warning was issued Saturday for the Wind, Little Wind and Popo Agie rivers after unseasonably warm temperatures complicated an already dangerous runoff season.
Flooding already has been reported on the Little Wind River in portions of the Wind River Indian Reservation. All affected rivers will rise to moderate flood stage by Sunday afternoon, according to weather service forecasts.
In Lander, the Middle Fork of the Pope Agie River was brimming to its banks in several locations Saturday afternoon. The Wind River at Riverton had spread beyond its normal channel, and the Little Wind south of the city was exceeding bank capacity in isolated areas. All were expected to overflow by Sunday and Monday.
Upstream around Kinnear, Crowheart and Dubois, where the channels are narrower, the Wind River was expected to reach moderate to major flood stage as early as Sunday afternoon, with flooding widespread by Tuesday.
Heavy late-season snowpack remains above 9,000 feet elevation in the western Wyoming mountains, National Weather officials wrote in their warning announcement.
Temperatures 15-20 degrees warmer than seasonal norms are expected through this weekend, with continued hot weather through the week.
Mountain temperatures where the snowpack remains will range from 60-70 degrees, while basin temperatures could reach the lower 90s by Sunday afternoon. The warm temperatures will accelerate snowmelt runoff through the middle of the week.
The flood warning has replaced the earlier flood advisory for the Wind River and Popo Agie River. Moderate flooding was expected through the weekend along the Wind River from Dubois downstream to Riverton, and the area around Black Bridge north of Riverton. Additional rises are expected on the river over the next 48 hours.
Current projections have the Wind River cresting late Tuesday or Wednesday around 11.6 feet. This crest would surpass the crests of June 1997 and June 1999, while falling just shy of the record crest of 11.8 feet in July 2011. The Middle Fork of the Popo Agie River at Sinks Canyon is expected to crest around 6.9 feet early Tuesday morning.
Timeline Accelerated snowmelt will cause continued increases in river and creek levels through at least late this week, officials wrote. Very high flows also are expected along the tributaries and main stems of the Wind, Green, Shoshone, and Sweetwater rivers by the end of next week.
People living near flood-prone areas should closely monitor water levels through the end of next week. Mountain streams run the highest in the late afternoon through early evening hours. Foothill communities typically see the highest levels during the late evening and early morning hours.
Do not attempt to cross streams during these times. The swift and cold water easily can carry humans downstream.
Officials recommended residents in low-lying areas of the county ensure their properties are shored up for flooding.
Last month, local emergency service agencies said they will not assist with private mitigation efforts, and will only respond to life safety incidents that threaten the community. Sandbags are available, however.
Residents are responsible for filling the bags with their own sand or fill material, though Fremont County commissioners last month were planning to make some sand available in Riverton, Lander and Hudson.
Anyone who wants sandbags to fortify their property can pick them up during normal business hours -- typically 7 a.m. to 3:30 p.m. Mondays through Fridays -- at the Fremont County Road and Bridge shops at 4421 Skyline Ave. Riverton, phone number 856-8122, and 1580 U.S. Hwy. 287 in Lander, phone number 332-2984.
Fremont County began the spring with 80,000 sandbags available. Distribution is limited to 1,000 -- preferably 500 at a time -- to prevent people from stockpiling materials.
In addition, residents who use Union Wireless can download a Commercial Mobile Alert Service application to receive emergency notifications through an integrated public alert and warning system, and Fremont County has published an evacuation plan on its website to let residents know what to expect if they are asked to leave their homes.
Evacuees should try to stay with friends, relatives, or in local motels if possible, as an evacuation shelter will only be established if necessary. A representative from the American Red Cross said last month that the agency is unlikely to open a shelter unless all hotel rooms are unavailable.
For further information, contact the Fremont County Emergency Management Agency at 856-2374.