FLOOD POTENTIAL IN THE LOWER COLORADO RIVER BASIN

The following are generalized discussions of the flood potential due to snowmelt in the Lower Colorado River drainage as of March 1, 2000. 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.

 

ARIZONA: The potential for snowmelt flooding in Arizona is low at this time. Snow water equivalent values as of March 1 ranged from 5% to 10% of median in the Gila, Little Colorado and Salt river basins. Storms during the first few days of March caused the snow water equivalent to increase to 35% of median in the Salt River Basin, to 40% of median in the Little Colorado River Basin and to 60% of median in the Verde River Basin. Runoff volumes for March through May are forecast to be much below median and no individual sites are expected to exceed flood stage.

 

NEW MEXICO: The potential for snowmelt flooding on the upper Gila River and on the Little Colorado River drainage in New Mexico is low at this time. Snow water equivalent values as of March 1 were 10% of median in the upper Gila River Basin. The March through May runoff volumes are forecast to be much below median with no individual sites forecast to exceed flood stage.

 

UTAH: The potential for snowmelt flooding along the Virgin and Santa Clara rivers is not high at this time. Nearly twice the average monthly precipitation fell over the Virgin River Basin during February. This increased snow water equivalent values from 35% of average on February 1 to 90% of average on March 1. Runoff volumes for the April to July period are forecast to be near 55% of average with no individual sites expected to exceed flood stage.