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<br />C''") <br />co <br />GO <br />--I <br />~., ) <br /> <br />"--" <br /> <br />collectively were assertedly impacting stream flows <br />on an over-appropriated river system. The only <br />difference was the complexity and size of the San <br />Luis Valley system. The protestants to groundwater <br />regulation argued that the hydraulic connection <br />between the aquifers and the streams was <br />non-existent or at least over-stated in this complex <br />geologic setting. They also pointed to the huge <br />amount of groundwater in storage (supposedly 2 <br />billion acre-feet) and the relatively large benefit <br />in the salvage of evapotranspiration. As a matter <br />of policy, they submitted, well regulation should <br />not be justified in the San Luis Valley. Proponents <br />countered that all the advantages of salvage and <br />utilization of groundwater storage could be realized <br />by the well pumping community in augmentation plans, <br />allowing pumping to continue; the only question was <br />who would bear the cost. <br /> <br />D. <br /> <br />The State's Case <br /> <br />1. Basic Geology - Building on basic published geologic <br />data from the U.S.G.S., the State, through testimony <br />and exhibits, painted the basic geologic situation. <br /> <br />2. U.S.G.S. Published Work - Principally Circulars 18 <br />and 29, derived from basic geology, water level <br />observations, water budget, observed springs in the <br />Conejos River region, and in the case of Circular <br />29, the analog model. See Attachment 2, Table 1, <br />Circular 18. <br /> <br />3. Review of Basic Surface Water Hydrology - Mass <br />diagrams of stream flows and diversions, inflow- <br />outflow and river gain analyses, cropping patterns, <br />snowpack and precipitation patterns. See <br />Attachments 3 and 4, Tables, Net River Gain, Conejos <br />and Rio Grande, for the Conejos River and Rio Grande <br />River, and Attachment 5, Estimate of Factors Causing <br />Decreases in Net River Gain. <br /> <br />4. Review of Basic Data on Groundwater Withdrawals Over <br />Time - See Attachment 6, Mass Diagram Large-Capacity <br />Well Withdrawals. <br /> <br />5. The State's OWn Digital Computer Model of the San <br />Luis Valley Groundwater-Surface Water Situation - <br />Based on the U.S.G.S. analog model and i.ts basic <br />assumptions, but going further to simultaneously <br />look at unconfined aquifer withdrawals and return <br />flows, and increased levels of pumping overall, the <br />State's model showed substantial impacts on the <br />surface streams as well as salvage of <br /> <br />-10- <br />