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25th Avenue Pit SWSP, (Amendment) Page 5 of 9 <br />May 30, 2017 <br /> <br />• Modeling using the State CU and the Modified Blaney-Criddle method with the Technical <br />Release (“TR21”) crop coefficients. <br />• The total structure daily diversion records were limited to the period of April 1 through October <br />31. <br />• Soil Conservation Service methodology for calculation of effective precipitation. Soils <br />underlying the historically irrigated property with the 138 shares of the Boyd and Freeman <br />Ditch are predominantly Aquolls and Aquents on 0 to 3 percent slopes. Available water <br />content of the soils as reported by National Resource Conservation Service (“NRCS”) Web Soil <br />Survey averages 0.11 inches per inch. <br />• Assumed ditch loss of 20 percent. <br />• Temperature and precipitation data were taken from the Greeley UNC climate stations (“NOAA <br />#3553 and NOAA #3546”). <br />• The farm was flood irrigated. The Applicant proposed a maximum irrigation efficiency of 55 <br />percent for flood irrigated pasture grass. Given the soils characteristics and the water-short <br />nature of the fields and the aerial photography evidence you concluded that 55 percent irrigation <br />efficiency is a conservative estimate. <br />• The modeled crop acreages are shown in Table 2 below: <br /> <br />Table 2-Summary of Crop Acreages Modeled <br />Period Irrigated Area <br />(acres) <br />1950-1960 70.59 <br />1961-1971 74.24 <br />1972-1977 73.90 <br /> <br />• Return flows assumed to be 75 percent surface water and 25 percent groundwater due to close <br />proximity of the historical irrigated lands to the Cache La Poudre River. Ground water return <br />flow was analyzed using Integrated Decision Support Alluvial Water Accounting System <br />(“AWAS”) software based on the Glover methodology according to the parameters summarized in <br />Table 3 below. <br /> <br />Table 3- Summary of Glover Parameters <br />Distance from the <br />Farm to the River (ft) <br />Distance from Boundary <br />to the River (ft) <br />Transmissivity <br />(gpd/ft) Specific Yield <br />955 11,503* 164,132* 0.2* <br /> <br />*Taken from the aquifer parameters decreed for the Flatiron Pits 3, 4, 5 (located within the <br />historically irrigated lands) in case no. 99CW231. <br /> <br />The HCU results are summarized in Table 3. <br /> <br />