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r <br /> Any lake surface that exists on the mine site prior to 1981 is exempt from the <br /> requirements of augmentation. There are a total of 1.6 acres of pre-1981 exposed water <br /> surface on the property which underlies the proposed gravel pit lake. <br /> In addition credit can be taken for historic groundwater consumptive use. Exhibit I lists <br /> the soil types for the subject site. There are 17.3 acres which contain the soil type <br /> 'Aquolls and Aquents, gravelly substratum'. The SCS reports that this soil has the <br /> characteristic of having a very high water table and supports.wetland plants and wetland <br /> wildlife. Based on this information it is concluded that there has been historic <br /> groundwater consumption due to subirrigation. <br /> The consumptive use of native vegetation in wet marshy areas along the Cache La <br /> Poudre River has been identified as 27.4 inches per year in water court in case W-7813- <br /> 74. This same value is assumed for the calculations of the net evaporation at the subject <br /> site. The net evaporation within the 17.3 acres with high water table conditions is equal <br /> to the gross evaporation for the months of March-December, 39.5 inches, minus the <br /> historic consumptive use, 27.4 inches. This equates to a net groundwater use of 14.6 <br /> inches or 1.01 ft. <br /> The total annual consumptive use of water requiring augmentation after the mining <br /> operation is completed is as follows: <br /> DESCRIPTION CONSUMPTIVE USE <br /> Reclaimed Lake Area with out 28.7 acre-feet <br /> Historic C.U. Credit (11.0 acres) <br /> Reclaimed Lake Area with 17.4 acre-feet <br /> Historic C.U. Credit (17.3 acres) <br /> TOTAL 46.1 ACRE-FEET <br /> O ratlonel Consumptive Uses <br /> No wash plant is planned for this site, therefore, no water losses associated with a <br /> washing process will occur. <br /> Water is retained in the material which is excavated from the site. It is estimated that 4% <br /> of the gross weight of the products is water. The volume of material mined is market <br /> driven and will vary from year to year. An average year is expected to produce 117,000 <br /> tons of material. This will consume 3.4 acre-feet of water. <br /> G-3 <br />