State Drought and Precipitation Update from NRCS, National Resources Conservation Service

Late April and early May storms brought increased precipitation in the northern portion of the state and continued cool temperatures helped to maintain snowpack. However, storms largely missed the southern half of the state, which is experiencing increasingly severe drought conditions. Storage remains below average throughout most of the state and water providers are preparing for continued drought conditions throughout the spring and summer.  

Governor Hickenlooper activated the Municipal Impact Task Force on May 10th in response to dry conditions is portions of the state, below average reservoir storage and continued water restrictions by municipal water providers.  

 As of the May 14, 2013 US Drought Monitor, 100% of Colorado continues to experience some level of drought classification. There have been improvements along the northern Front Range and northeastern plains while conditions have declined to the south. D0 (abnormally dry) and D1 (moderate) conditions cover 28% of the state; while D2 (severe) covers 47% and D3 (extreme) accounts for an additional 9%. 16% of the state is now experiencing exceptional drought (D4), a slight increase from last month. 

Spring snow storms brought significant gains in the snowpack to the Colorado and South Platte River basins, which both achieved near normal peak accumulation with 94 and 105% of the average peak snowpack, respectively. The Yampa/ White basin also had a near normal peak at 91% of normal. All three basins experienced later than normal peaks, by nearly two weeks. All other basins had less than normal peak snow accumulation. The lowest peak snowpack, as a percent of normal, was in the Upper Rio Grande basin (68%) while the Southwest basin had 74% of average. The Arkansas and Gunnison had similar peak snowpack accumulations of 73 and 76% of average respectively.*  

Despite recent gains in snowpack, municipalities and water providers are still responding to drought conditions with watering restrictions. The CWCB drought response portal www.COH2O.co continues to help individuals determine the restrictions in their specific community. Northern Colorado Water Conservancy District continues to hold the C-BT quota at 60%.  

As of the first of May, statewide reservoir storage is at 74% of average. The highest storage levels are in the Yampa/ White River Basin, at 107% of average, while the lowest storage in the state is the Arkansas River basin at 52% of average. All other basins range from 54% to 88% of average. Last year at this time the state was at 112% of average reservoir storage.*  

Streamflow forecasts for the spring indicate below average streamflow across the state. The Colorado and South Platte have the highest streamflow forecasts ranging from 70-100% of normal, with forecasts better in the headwaters than downstream. Forecasts in the Colorado downstream of Glenwood drop to 62-68% of average. The lowest forecasts in the state are in the Upper Rio Grande, with flows ranging 24 to 54% of normal. The Southwestern basins and the Arkansas also have low forecasts ranging from 30-68% of normal.  

Surface Water Supply Index (SWSI) values remain negative despite improvements in the north. Below average reservoir storage and low streamflow forecasts contribute to these values and data reflect conditions on May 1, 2013. The US Drought Monitor illustrates current drought conditions across Colorado. Most of the state continues to experience severe drought conditions, although improvements occurred along the northern Front Range and on the northeastern plains. The southern part of the state has seen conditions deteriorate over the last month. 

Despite recent gains in snowpack, streamflow forecasts remain below normal across the state, in part due to dry soil conditions. If these forecasts prove to be true, it will affect how much reservoirs are able to fill. 

The long term experimental forecast for July through September of this year is projecting above normal moisture for the northeastern plains of the state (left). Additionally, the Climate Prediction Center at NOAA is forecasting persistent drought conditions across western portions of the state, with some relief possible on the northeastern plains. 

Precipitation Totals for May 2012, compared to May 2013 for southeastern Colorado are as follows: 

                                               May 2012                                   May 2013 

Eads                                          0.39                                            2.24
Haswell                                    0.28                                             0.35
Holly                                         0.31                                            1.07
John Martin Dam                    0.14                                           0.17
La Junta                                     0.67                                           0.22
Crowley                                     0.32                                           0.52
Lamar                                         0.22                                           0.37
Las Animas                                0.33                                            0.09
Springfield                                 0.53                                            0.76
Trinidad                                      1.18                                            0.51
Walsh                                          1.11                                            0.46