Section 2 Drought Severity Indicators

Outlook map for the United States.

 Weather projections for temperature and precipitation (produced by NOAA or others):

 8 to 14 day

 Monthly outlook

 Three-month outlook

 Six-month outlook

 Actions taken by local, regional and/or state governments or other water suppliers regarding water use

 Drought response actions taken by state water officials

 Water availability conditions and/or drought conditions in the South Platte River basin including cumulative precipitation compared with the 30-year average in the South Platte River watershed.

 Ambient water treatment capacity:

 Algae conditions in each of the reservoirs used by Centennial Water

 Filter run times at the Joseph B. Blake Water Treatment Plant

 Other pertinent water quality or operational limitations

 System demand factors:

 Measured and anticipated landscape irrigation demands as compared to the computed five-year average

 Measured and anticipated evaporation losses as compared to long-term averages

The significance of indicators is dependent on the season. For example, from January through May, snowpack and early spring runoff are important indicators; from April through June, stream flow is an important indicator of likely senior calls on the South Platte River; and from June through December, reservoir storage, water use and precipitation in the South Platte basin are important indicators. Each drought event is unique, and the impact of each drought indicator can vary greatly based on the time of year.

Reservoir storage is the result of multiple factors affecting supply, including weather, snowpack, soil moisture, runoff, water rights, bypass requirements, collection system limitations and water use.

Aggregate reservoir storage in Centennial Water’s surface-water system usually peaks in May or June during the early spring snowmelt. For this reason, forecasted system-wide June 1 reservoir storage is an important indicator for drought response during the runoff season.

System wide reservoir storage is forecasted and closely monitored throughout each year. Forecasts of reservoir storage are updated monthly. Predictions are based on measurements of snowpack, stream flows, bypass requirements, soil moisture, water usage, precipitation and the previous year’s reservoir carryover storage.

Regardless of the water supply situation, Centennial Water staff routinely monitor hydrologic conditions, and this monitoring intensifies during dry periods. If conditions change after a water shortage and response have been declared, the declaration can be lifted, or the level of drought response can be adjusted.

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