Colorado Water Supply Conditions Update

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? RIO GRANDE BASIN , Basinwide Conditions Assessment • The SWSI value of -3.7 indicates that for December the basin water supplies were well below normal. The Natural Resources Conservation Service reparts that January 1 snowpack is 19% of normal. Flow at the gaging station Rio Grande near Del Norte was 215 cfs, as compared to the long-term average of 188 cfs. The Conejos River near Mogote had a mean flow of 34 cfs (65% of normal). Storage in Platoro, Rio Grande, and Santa Maria reservoirs totaled 124% of normal as of the end of December. Alamosa received 0.03 inches of precipitation during the month, 0.41 inches below normal. For the year 1999, Alamosa's total precipitation of 7.58 inches was very near the annual average. Alamosa's temperature averaged 42.8° during the month, the highest December average in over 20 years. Outlook Stream flow in the basin should be slightly below average for the next few months. Lack of significant precipitation will bolster dust storms when the wind picks up. Administrative/Management Concerns Colorado exceeded the Rio Grande Compact delivery obligation to New Mexico and Texas in 1999 by approximately 5,000 acre-feet. This amount was very close to hitting the target considering the unusual year the basin experienced. Early forecasts of a drought due to Iow snowpack changed dramatically as late spring snow storms and heavy summer rains reversed the early trend. A very dry autumn forced stream flow back to normal levels. 7he result was about 910,000 acre-feet indexed at the Rio Grande near Del Norte gaging station. Stream flow in an average year totals 655,000 acre-feet. The impact of the rain was not felt as strongly in the Conejos River drainage. Indexed flow on the Conejos River near Mogote totaled 223,000 acre-feet in 1999, compared to an average of 241,000 acre-feet. Closed Basin Project delivery to the Rio Grande totaled 20,400 acre-feet. Ail project canai deliveries met water quality standards. Public Use Impacts Snowfall at the beginning of January helped a bit, but the basin is getting another poor start on snowpack this year. 5 Jan-00 fi31;E.SB,I(ATNE ?/qRS 35.ooo 3o.aoo zs.ooo m m V ? ?,000 N O1 N O ?o 15,000 m a m N ? ??,OOD 5.000 0 RoCYande Ftatao Sartaveria BAeg. 12131 Cantf?ts 012131/99 C.aY0n1s