DWR_4151809 - Laserfiche WebLink

r J i COLORADO WATER SUPPLY CONDITIONS REPORT June 14, 1990 Precipitation is for the month of May. Both high elevation and low elevation precipitation data are included. Reservoir storage and snowpack conditions were measured on June 1, 1990. Reservoir Basin Storage Precipitation Snowpack South Platte 110% 84% 83% Arkansas 78% 127% 83% Rio Grande 60% 114% 56% Gunnison 90% 98% 36% Colorado 79% 64% 61% Yampa/White N/A 97% 55% San Juan/Dolores 87% 94% 34% *Precipitation and snowpack data as a percentage of normal *Reservoir storage as a percentage of storage on June 1, 1989 The Surface Water Supply Index (SWSI) developed by this office is used as an indicator of water supply conditions in the state. It is based on reservoir storage, streamflow, and precipitation for the summer period (May 1 - December 1) and reservoir storage, snowpack, and precipitation for the winter period (December 1 - May 1) . Weight factors are applied to each of the measured hydrologic components in computing the SWSI values. These computations are based on the probability of non-exceedence of individual components; that is, the probability that a measured value is equal to or less than the historic average. During the summer period, streamflow is the primary component in each basin except the South Platte. The following SWSI values were computed for each of the seven basins on June 1, 1990: Change from Basin SWSI Value Mav 1, 1990 South Platte +0.3 +1. 1 Arkansas -0.7 +0.1 Rio Grande -1.7 +1 .2 Gunnison -1.4 0.0 Colorado -2.5 -0.8 Yampa/White -3.8 -1 .2 San Juan/Dolores -2.1 +0.4 SCALE -4 -3 -2 -1 0 +1 +2 +3 +4 Severe Moderate Below Near normal Above normal Abundant drought drought normal supply *Data provided by the Soil Conservation Service, Snow Survey Office (Denver) , U.S. Department of Agriculture and the National Weather Service