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• • 0 <br />Project: Cripple Creek Geohydrology Date: 4/8/2008 <br />Task: Diatremal Flow Model - With Granite Page 6-1 <br />CONCEPT <br />1. Water enters diatreme by infiltration at some rate from the surface <br />a. Without interception in unaffected areas and mined areas <br />b. With interception in areas of overburden storage (mines, storage areas) <br />2. Water flows to the Carlton Tunnel: <br />a. Water drains rapidly (and at a variable rate) from the diatremal area directly penetrated by the tunnel <br />b. Water drains slowly (and at a constant rate) from the rest of the Diatreme and the granite <br />3. Flow exits from diatreme by a resistive flow conduit to Carlton Tunnel <br />4. Water is stored in the diatreme by build-up of water level <br />PARAMETERS <br />Average Infiltration rate 21.00% 25% pre mining (Maxey and Eakin (1949) for 20" precip) <br />Precipitation 19.58 inches Average 1992-2007 <br />Flow from tunnel 1662 gpm Average 1992-2007, adjusted for changes in 1996 <br />Infiltration area for flow 340850490 sq.ft. Computed from tunnel flow divided by infiltration depth <br />Area of diatreme 200551792 sq.ft. Diatreme outline inc. three outliers, but not deleting inliers <br />Additional granite area 140298698 sq.ft. Computed from area required to obtain flow <br />Average radial dist. increase 1,950 ft By offsetting internal diatreme area . <br />Area of Lobe 88819867 sq.ft. Area of southeast lobe (essentially the disturbed area) <br />Area of constant infiltration 252030624 sq.ft. By subtraction <br />MODEL CALIBRATION PARAMETERS <br />Drain-down head 7000 ft msl Approximate Carlton Drain point <br />Initial head in diatreme 7270 ft msl Estimated from drill hole in Cresson Pipe <br />Flow/unit head 5.5 gpm/foot Calibration parameter <br />Drainable porosity 0.5% Calibration parameter <br />Diatremal pool area 52,550,161 sq.ft. From DB-LEC0-2.xls @ 7250 ft msl <br />Adrian Brown Consultants, Inc.