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1 <br />E <br />Cn <br />i 0.1 <br />0 <br />3 <br />CU <br />L <br />0.01 <br />• Measured Drawdown <br />Curve -Fit with STRMAQ <br />1 10 100 1000 10000 <br />Time, t (min) <br />Figure 7 — Comparison of measured drawdown at observation well B2ES during a <br />stream/aquifer analysis test at the Tamarack State Wildlife Area and predicted <br />drawdown by the STRMAQ model considering the influence of finite stream width <br />of the slough channel. <br />Parameter values for both observation wells agree with reported values of aquifer <br />parameters at the site and also with measured streambed conductivity in the slough <br />channel from the falling -head permeameter tests. A number of reports are published that <br />document representative aquifer parameters for the lower South Platte River and the <br />Tamarack site. The USGS (Hurr and Schneider, 1973) published transmissivity and <br />saturated thickness maps of the lower South Platte River alluvial aquifer. Burns (1985) <br />presented a report of a calibrated groundwater flow model at the Tamarack site. Also, <br />several aquifer tests have been performed at Tamarack over the past several years by <br />researchers with the Northern Colorado Water Conservancy District and the Colorado <br />Division of Wildlife (Halstead, 2001). Based on these data sources, Halstead (2001) <br />reports reasonable values for aquifer parameters that match considerable well to the <br />parameter values obtained from the stream/aquifer analysis tests: <br />• Aquifer Conductivity, K: approximately 90 to 200 m -d-1 with an average of <br />130 m -d -1 <br />• Specific Yield, Sy: 0.12 -0.30 with an average of 0.15 <br />11 <br />