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Water stored under direct flow rights is typically released when river flows begin to decline in <br />the later summer. For efficiency purposes, the Association prefers to combine releases of direct <br />flow storage water with direct flow water diverted at their headgates. As required by decree, <br />water stored under direct flow rights must be used within the same season it is stored. <br />Several owners of the Association are also entitled to receive deliveries of water from Santa <br />Maria and Continental reservoirs that was stored under the reservoirs own water rights. Owners <br />request these deliveries from Association representatives who then attempt to combine reservoir <br />water orders with direct flow diversions to improve delivery efficiencies. The Association <br />generally has control over the timing and amount of reservoir water that may be run through the <br />Rio Grande Canal. <br />Use of Groundwater <br />Use of groundwater is an important component of irrigation under the Rio Grande Canal. The <br />transition to intensive groundwater use began in the late 1950s, and today, almost all share <br />owners in the Association have their own groundwater well. This transition to a reliance on <br />groundwater was a result of high variability in surface supplies, and because the service area is <br />typically water short without supplemental groundwater. <br />Most wells within the Canal service area are located in the unconfined aquifer. Several wells <br />located in the area of La Garita and to the north are in the confined aquifer and are artesian. The <br />Association does not keep records of groundwater pumping, but most wells run at rates between <br />1,800 and 2,000 gpm. The State maintains pumping records for wells used as augmentation <br />supplies. <br />There are eight wells in the Canal service area where water levels are regularly monitored. The <br />Association has noticed significant changes (declines) in the water table depth and groundwater <br />supplies over the past 50 years. <br />The practice of using surface water to recharge the unconfined aquifer within the Association's <br />service area was formally recognized as a beneficial use in Case No. W-3979. This method of <br />recharge has been practiced by the Association for many years, and is integral in efforts to <br />maintain water levels. In fact, a majority of the water currently diverted from the Rio Grande is <br />used expressly for this purpose. Many of the land owners within the service area have created <br />pits or basins where surface water can be applied for the purpose of recharge. <br />The decree issued in Case No. 79CW091 allowed for diversions by the Association from the Rio <br />Grande outside of the normal irrigation season (November and December) for winter recharge. <br />The Association participates in the winter recharge program whenever water is made available by <br />the State (when Rio Grande Compact obligations have been met). During these months, diverted <br />water (typically 100 cfs) is sent down the Canal then diverted onto sagebrush lands, dyked lands <br />and recharge pits (often at corners of center pivots). Losses from the Canal itself also facilitate <br />aquifer recharge. The Association continues this practice until freezing conditions prevent it or <br />the State determines Compact delivery requirements require diversions be curtailed. . <br />C:Acdss\RGCanal.doc Rio Grande Canal Water Users Association Interview June 13, 1999 -Page 5 of 7 <br />