FLOOD POTENTIAL IN THE EASTERN GREAT BASIN

The following are generalized discussions of the flood potential due to snowmelt in the Eastern Great Basin drainage as of May 1, 1998. Discussions are segregated by state. It is important to understand that the potential for flooding may increase dramatically if snowmelt accelerates rapidly due to above normal temperatures or if significant rain events occur.

UTAH: The potential for flooding due to snowmelt runoff is higher than usual for this time of year for much of the eastern Great Basin. This is due primarily to wet and cool weather during much of April that increased the snowpack and delayed the onset of snowmelt.

Areas of greatest concern include City Creek near Salt Lake, the western slopesof the Wasatch Mountains from Bountiful north to Ogden, streams draining into the Tooele Valley, and the Beaver River drainage in southwest Utah. Snowpack in these areas ranges up to near 200 percent of average. High flows near bankfull are likely this spring. City Creek is expected to peak just below flood flow.

Higher than usual flood potential exists also for the Sevier River basin. Snowpack is highly variable in this area, depleted at low elevations and generally ranging from 80 to 150 percent at mid and higher elevations. Although high flows are possible, flood problems due solely to snowmelt runoff are not anticipated at this time.

 

 

IDAHO: The potential for snowmelt flooding in the Great Basin of Idaho is lower than usual for this time of year. Currently the snowpack is near average over the Bear River Basin of southeast Idaho. Seasonal runoff volumes are expected to range from 85 to 100 percent of average. Flood problems due solely to snowmelt runoff are not anticipated at this time

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