DWR_4151798 - Laserfiche WebLink

RIO GRANDE BASIN Basinwide Conditions Assessment: The SWSI value of +1.5 indicates that the current SURFACE WATER SUPPLY INDEX conditions are above normal. This is the highest SWSI value in 3 o- the state. This represents a significant improvement from 4- conditions on April 1, 1990, when the SWSI value was -2.8. . ,_ Snowpack measured on April 1, 1991,was 111%of average. The - j � ,�aC month of March was an excellent snow period for the San Juan - ' " 1... `. and Sangre De Cristo mountains surrounding the Rio Grande ' — inn "ji' basin. Snow water equivalency is approximately 21 inches. ' a ' •. Precipitation measured 184% of verage for the month and is -,- ' . `i ; I'� 130% of average for the water year. Streamflow conditions on 2 -2- the Rio Grande and its tributaries in the San Luis Valley were -5- average for the month. Flow at the key gaging station, Rio _. , Grande near Del Norte, averaged 220 cfs for the month as `""" `""'° J""" '""" AI.' """ JAN22 J""" '""'° Jaw r6w► 1114 compared to the historic monthly average of 251 cfs. Flow at the key compact gaging station,Conejos River near Mogote,averaged 64 cfs. Above average storage occurred in basin reservoirs in March, but overall storage is still only 90% of average. Rio Grande Reservoir increased storage(usable)from 11,100 acre-feet RID GRANDE NR. DELNORTE on March 1st to 12,700 acre-feet on April 1st. Terrace Reservoir ,xi "WISP � ''`"� over the same period increased its storage (usable) from 6,800 195 .` acre-feet to 7,800 acre-feet. Soil moisture conditions are good. 146 1 130 __„.„.....,„„...> Outlook: 9 ,o If warm spring winds do not deplete the snowpack prior a 'oo to runoff, streamflow in the basin should provide an adequate !� W , water supply for the 1991 irrigation season. Adequate storagei ...7° ' capacity exists for above normal runoff. Streamflow forecast is 5. a lowest in the Saguache Creek drainage above Saguache at 103% of average and is highest in the San Antonio River at 153% of 5,5 average. Streamflow for the Rio Grande mainstem at Del Norte °°` "°" °'° har`" H is forecast to be 118%of average. Recharge of the ground water ° '"`T + °"''`'°"' 0 .G . „" should be significant with increased diversions occurring in high recharge areas. This will help to maintain sustained pumping rates in the unconfined aquifers. Rio Grande Basin Reservoir Supplies Administrative/Management Concerns: l°17 f The entire combined flow of the Conejos River and Rio ;: Grande was delivered to the stateline duringthe month of March „ / � to satisfy 1991 compact obligations. Water users agreed to i ,Y \ maintain this period of no diversions through April 15, 1991. A g- total of 64,000 acre-feet has been delivered this water year to the aI / stateline. The Closed Basin Project contributed 6,700 acre-feet of .. -/Z\ , that amount as of April 1, 1991. Compact deliveries made now �� i� will reduce the amount of water which will need to be delivered 1-\\ 3 duringthe irrigation season. It appears that because of the 'A g PP higher than normal.runoff projections, that the Rio Grande and ° _./A,, i\ Conejos index flows will be approximately 700,000 and 420,000 °"`°"° """""" acre-feet respectively. This will require a delivery obligation of ® ""0' ""Car ® V31"Canc.,. just over 200,000 acre-feet for each-river system in 1991. Public Use Impacts: This year's snowpack and expected runoff will provide a number of possibilities for not only the irrigators but also for recreational activities as well. Fishing opportunities in the reservoirs in the basin, as well as the streams and rivers, should be excellent throughout the season. This will be a welcome change after the last three years of much below normal runoff in the Rio Grande basin. 5