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RIO GRANDE BASIN Basinwide Conditions Assessment The SWSI value for the month was 3.7. The Natural Resources Conservation Service reports that March 1 snowpack is 1690/0 of normal. Flow at the gaging station Rio Grande near Del Norte averaged 183 cfs (101 % of normal). The Conejos River near Mogote had a mean flow of 58 cfs (111 % of normal). Flow to the state line was 1050/0 of normal. Temperatures were low enough during February to hold off any significant melt of the abundant snowpack. Weather conditions in the San Luis Valley were colder and wetter than normal during February. Alamosa received 0.57 inches of precipitation during the month, 0.36 inches above normal. This precipitation kept a layer of snow on the Valley floor and temperatures cold. Storage in Platoro, Rio Grande, and Santa Maria reservoirs totaled 1090/0 of normal as of the end of February. Outlook Heavy snowfall continued throughout February in the upper Rio Grande basin. The current snowpack in the basin is the highest early March level since 1979. Recent NRCS stream flow forecasts are calling for 1350/0 (Sangre de Cristo Range) to 201 % (Rio San Antonio drainage) of average runoff this year. Expected runoff at the Rio Grande near Del Norte gaging station is 160 percent of normal and 165 percent of average for the Conejos near Mogote. There is a very good chance all reservoirs in the basin may fill with the exception of Sanchez Reservoir and those with storage restrictions: Terrace and Continental. Platoro Reservoir will be for flood control operations this spring. Administrative/Manaqement Concerns Local officials are beginning the process of preparation for high runoff and potential flooding. Sandbags have been ordered and stream channel clearing and headgate maintenance are a serious concern. Depending on the severity of the melt-out, runoff levels might easily exceed the last high runoff year, 1995. The 69th annual meeting of the Rio Grande Compact Commission will be held at Apodaca Hall in Santa Fe, New Mexico on March 27, 2008 at 9 a.m. The public is invited to attend. The 2008 annual meeting of the Costilla Creek Compact Commission will be held at the Clarion Inn of the Rio Grande in Alamosa on May 8, 2008 at 10 a.m. The public is invited to attend. Public Use Impacts Winter sports enthusiasts reliant on snowcover enjoyed the bounty of a very snowy month. Mar-08 RIO GRANDE BASIN SNSI HISTORY I- W S W ::J ....J <C > 0 >< w o z - -1 >- 0:: o -2 -3 -4 Jal1-gg Jan-DO Jan-D1 Jan-D2 Jal1-03 Jan-04 Jal1-05 Jal1-00 Jal1-07 Jart-OO rvDNTH / YEAR RIO GRANDE NR DELNORTE, FLOW BY WATER YEAR 180,000 160,000 ~ 140,000 LL cb ~ 120,000 ~ 100,000 ---l LL ~ 80,000 i= :s 60,000 :J ~ B 40,000 20,000 o O:i Nov Dee Jan Feb rvlarch -----8-- WET (1987) ~ DRY (2002) ---fr-- A VG -* 2008 REPRESENTATIVE RESERVOI RS 30,000 25,000 Q3 ~ 20,000 U co ai ~ 15,000 o U5 Q) ~ 10,000 :J 5,000 Rio Grande P1atoro Santa rvlaria III Avg. 2128 Contents I!JJ 2129/08 Contents 5