FLOOD POTENTIAL IN THE UPPER COLORADO RIVER BASIN

The following are generalized discussions of the flood potential due to snowmelt in the Upper Colorado River drainage as of March 1, 1997. 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.

COLORADO: The potential for flooding from snowmelt in western Colorado is moderate to high. As of March 1, the snowpack was above to much above average in most areas. The most probable, or 50% exceedance probability, peak flow estimates call for near flood conditions at several points. Flooding may occur at other points along the river where no National Weather Service flood stages exist. Areas of possible concern include parts of the Yampa, Eagle, East and lower Colorado Rivers. However, as of press time, warm temperatures and lack of precipitation are decreasing the flood potential, indicating once again that future temperatures and precipitation are the keys to possible flooding.

WYOMING: The snowmelt flood potential for the Wyoming portion of the basin is higher than normal at this time. The snowpack over this basin is above to much above average with streamflow volumes expected to be above to much above average. Peak flows are also expected to be above normal, with some over-bank flow probable. However, at this time no forecast points are currently expected to exceed flood stage.

UTAH: At this time, the snowmelt flood potential over the Utah portion of this basin is high on the Green River in the vicinity of Jensen, due mainly to high flows expected out of the Yampa River system. Elsewhere the snowmelt flood potetntial is higher than normal. Above to much above average snowpack over most of the basin will lead to high flows on many of the streams in Eastern Utah with over-bank flows probable in some areas. Particular areas of concern include Ashley Creek and Dry Fork draining out of the Uintas and portions of the Strawberry and Duchesne River systems. The flood stage on the Green River near Jensen is expected to be exceeded during this runoff season.

NEW MEXICO: The snowmelt flood potential over the New Mexico portion of the basin at this time is higher than normal. Snowpack for locations upstream of the Four Corners area is much above average. Volume forecasts for southwest Colorado streams draining into New Mexico are much above average. However, no forecast points are projected to exceed flood stage due solely to snowmelt during the spring and summer season of 1997.