####018008014#### FGUS75 KPUB 091945 ESFPUB COC003-009-011-015-021-023-025-027-041-043-055-061-065-071-079-089- 099-101-105-109-119-200700- Water Supply Outlook National Weather Service Pueblo CO 0145 PM MDT Tue April 9, 2024 ...Water Supply Outlook for Southeast and South-Central Colorado as of April 1, 2024... The month of March brought additional, beneficial precipitation to the mountains of southeast and south-central Colorado with 186 percent of normal precipitation observed for the Arkansas River Basin and 176 percent of normal precipitation observed for the Rio Grande Basin. While a few locations in the Arkansas River and Rio Grande Basins saw slightly below normal precipiation, mostly above normal precipitation led to continued improvement in mountain snowpack conditions by the end of March. Water Year-to-date precipitation, as of April 1, 2024, was above normal at 115 percent for the mountains of the Arkansas River Basin and near normal at 98 percent for the mountains of the Rio Grande Basin. Water Year-to-date mountain snowpack snow water equivalent (SWE), as of April 1, 2024, was trending at 117 percent of normal for the Arkansas River Basin and 106 percent of normal for the Rio Grande Basin. The Rio Grande Basin continued its trend of month- over-month improvement from 86 percent of normal snowpack SWE on March 1, 2024 and only 66 percent of normal snowpack SWE on February 1, 2024. Mountain snowpack SWE for Colorado is at or near its typical peak for the accumulation season. Snowpack SWE is currently at or above nornmal at individual SNOTEL stations in the Sawatch Range along the Continental Divide. Snowpack SWE at SNOTEL stations in the La Garita and San Juan Mountains are now trending at above or well above normal while a larger spread of conditions, ranging from 90 to 120 percent of normal, are found at SNOTEL stations in the Sangre de Cristo Mountains. Mountain snowpack SWE for the Pikes Peak Region and Wet Mountains continues to trend over 200 percent of normal. For the Arkansas River Basin, the above normal precipitation observed for the month of March has led to continued improvement to the streamflow volume forecasts for the upcoming runoff season. Forecast locations in the upper Arkansas River Valley continue to trend more favorably due to better snowpack and soil moisture conditions compared to forecast locations for drainages along the east slope of the Sangre de Cristo Mountains. The following are the latest available seasonal runoff forecasts for selected locations in the Arkansas River Basin assuming normal precipitation through the snowmelt season: Location % of Normal Runoff Period Arkansas River Granite 103 Apr-Sep Salida 102 Apr-Sep Canon City 101 Apr-Sep Above Pueblo 101 Apr-Sep Chalk Creek Near Nathrop 108 Apr-Sep Grape Creek Near Westcliffe 74 Apr-Sep Huerfano River Near Redwing 82 Apr-Sep Cucharas River Near La Veta 88 Apr-Sep Purgatoire River Trinidad 76 Apr-Sep These forecasts reflect natural runoff only. Actual observed runoff will likely be affected by upstream water management. The forecasts below are for two locations on the southeast Colorado plains in the lower part of the Arkansas River Basin. These forecasts include projected upstream water management that is expected to impact streamflow. Arkansas River Las Animas 103 Apr-Sep Purgatoire River Las Animas 83 Apr-Sep For the Rio Grande Basin, continued widespread improvement to the streamflow volume forecasts for the upcoming runoff season occured due to benefical, above normal precipitation observed across the basin over the month of March. Foecasts at individual locations on the west side of the San Luis Valley, for drainages of the eastern San Juan Mountains, are trending above 90 percent of normal with the most month-over-month improvement observed for the Saguache subbasin draining from the La Garita Mountains. Widespread improvement also was observed for all locations along the east side of the San Luis Valley, for drainages of the west slope of the Sangre de Cristo Mountains. Runoff projections for most locations are trending closer to normal above 90 percent while the Costilla subbasin remains below normal in the 65 to 75 percent range. Mostly below normal seasonal runoff projections are still influenced by persistent drought and soil moisture deficits throughout the Rio Grande Basin, but slow and steady improvment in hydrologic conditions continues to occur heading into the runoff season. The following are the latest available seasonal runoff forecasts for selected locations in the Rio Grande Basin assuming normal precipitation through the snowmelt season: Location % of Normal Runoff Period Rio Grande River Thirty Mile Bridge 94 Apr-Sep Wagon Wheel Gap 96 Apr-Sep Near Del Norte 93 Apr-Sep Near Lobatos 92 Apr-Jul South Fork Rio Grande River South Fork 91 Apr-Sep Saguache Creek Near Saguache 125 Apr-Sep Alamosa Creek Terrace Reservoir Inflow 92 Apr-Sep La Jara Creek Near Capulin 93 Apr-Jul Conejos River Platoro Reservoir Inflow 93 Apr-Sep Near Mogote 99 Apr-Sep San Antonio River Ortiz 99 Apr-Sep Los Pinos River Ortiz 92 Apr-Sep Ute Creek Near Fort Garland 84 Apr-Sep Sangre de Cristo Creek Near Fort Garland 96 Apr-Sep Trinchera Creek Above Turners Ranch 89 Apr-Sep Costilla Creek Costilla Reservoir Inflow 75 Apr-Jul Near Costilla 67 Apr-Jul Culebra Creek San Luis 99 Apr-Sep This outlook is based on recent observations of snowpack and assumes normal precipitation for the upcoming snowmelt season. If the actual observed precipitation deviates from normal, then the actual observed runoff will likely be different than the forecasts presented in this outlook. This is the fourth of six scheduled outlooks for the 2024 runoff season. Users of this product are encouraged to contact the National Weather Service in Pueblo for continued updates on the water supply situation. Meteorological conditions could develop that would have a significant impact on water supply forecasts. For additional hydrologic products available on the world wide web, visit the Pueblo National Weather Service web site at: weather.gov/pub. Or visit the NWS River Forecast Centers or NRCS that provide daily and monthly water supply forecasts at: cbrfc.noaa.gov/wsup/graph/west/map/esp_map.html nrcs.usda.gov/wps/portal/wcc/home/waterSupply This message is the result of the collaboration between the National Weather Service and the Natural Resources Conservation Service. JML