Summary of Select Water Storage and Flow Conditions

• File Number: 8461.450
• Description: EAC/RCC
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 4/19/2000
• Author: Rick Brown, Randy Seaholm
• Title: Summary of Select Water Storage and Flow Conditions
• Water Supply Pro - Doc Type: Correspondence

Reservoir Storage
A summary of the status of select reservoir storage and reservoir capacity is provided in
Figure 3. Generally, these major South Platte reservoirs are near allowable storage
capacity. It should be noted that 3ackson Reservoir likely will not store additional water
due to maintenance activities. Figure 7 shows reservoir storage for Colorado with the
South Platte basin estimated to be slightly ahead of normal storage patterns at 111 percent
of average.
Snow Pack
State wide snow pack for Colorado as of Apri12000 is shown in Figure 8. Overall snow
pack for Colorado is 90 percent of average. Specifically, for the South Platte basin snow
pack is 90 to 110 percent of average.
Figure 9 shows the Snow Water Equivalent (SWE) in inches for the South Platte basin.
As of Apri17 the SWE for the South Platte basin was approximately 13 inches, which is
99 percent of average.
The Surface Water Supply Index (SWSI) is an indicator of mountain-based water supply
conditions developed by the Natural Resource Conservation Office and the Colorado
State Engineers Office. The SWSI is based on snow pack, reservoir storage, and
precipitation for November through April. During the winter, snow pack is given the
most emphasis, except on the South Platte where reservoir storage is given the most
weight. During the summer actual stream flow conditions begins to replace snow pack.
The SWSI for Colorado as of March 1, 2000 is shown in Figure 10. The SWSI for the
South Platte basin is 1.6, indicating an average too slightly above average water supply.
III. SUMMARY
As of Apri12000 water supplies in the South Platte basin appear to be shaping up for an
average water year. Almost all water related indicies are at or slightly above average.
However, as always precipitation and temperature in the spring and summer will have a
significant impact on the rate of the snow pack melt, and the actual quantity of our water
supplies. Monitoring of these factors is important throughout the summer and fall to
document changes in current projections.
Finally, a summary of a recent meeting of Colorado's Flood Task Force indicates that the
current summer outlook is for hotter and dryer conditions than normal. However,
monsoonal cooling in July- September may moderate the predicted summer outlook.
2