Colorado Water Conservation Board, August 2015 Drought Update

Colorado Water Conservation Board, August 2015 Drought Update

Colorado remains largely drought free despite decreased precipitation in late July and early August. This is in part due to moderate summer temperatures over the same time period. Drier conditions in recent weeks have led to declining soil moisture levels, but overall evapotranspiration rates are below average for the season, and pasture conditions are reportedly good. Water supplies continue to increase and statewide storage is the highest we have seen since 2000. Water providers are reporting system-wide storage levels greater than 90 percent of capacity. Demand is also lower than this time last year.

State wide water year-to-date precipitation is 99 percent of average, up 19 percent since May 1st. Precipitation to-date in August is 79 percent of average following multiple months of above average precipitation.

July temperatures were below average resulting in the coolest July in over a decade (2004). August temperatures have been warmer, but the western slope continues to be below average.

In the San Miguel, Dolores, Animas and San Juan river basins August precipitation to-date is 118 percent of normal, exceeding average total August precipitation in just the first two weeks of the month. Coupled with abundant accumulation in the two previous months this region is seeing greatly improved conditions.

Reservoir Storage statewide is at 117 percent of average as of August 1st. The Arkansas has the highest levels in the state at 153 percent of average. John Martin Reservoir in the lower Arkansas is experiencing its highest storage levels since 2001. The Upper Rio Grande has the lowest storage levels at 92 percent of average; this is also the only basin with below average storage.

The Surface Water Supply Index (SWSI) is abundant across much of the South Platte and Arkansas, and near normal in the remainder of the state. The state has recently complete a automation tool for the index and a revised detailed monthly report can be found at http://water.state.co.us/DWRDocs/Reports/Pages/SWSIReport.aspx

El Niño has gained strength over the last few months and continues to be forecasted as a strong event, if not a “Super El Niño.” The last “Super El Niño” was in 1997 when Colorado experienced above average precipitation. Short term forecasts favor mountain precipitation over the plains with localized storms statewide. The following precipitation levels are for southeastern Colorado communities.