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Aggregate Industries South Platte Combined SWSP April 13, 2018
<br />Plan IDs 3614, 4773, 3624, 4772, 4616, 3437, 3376, 3650, 3668, and 5475 Page 5 of 20
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<br />Depletions
<br />The depletions resulting from evaporation, water lost in mined product, dust control and
<br />concrete batching at each site are shown in Table C below:
<br />Table C – Depletion Summary (all amounts in acre-feet)
<br />Site Name Evaporation Water Lost in
<br />Mined Product Dust
<br />Control Concrete
<br />Batching Total Lagged
<br />Depletions
<br />Lagged
<br />Dewatering
<br />Depletions
<br />Impacting
<br />the Riverb
<br />Total
<br />Lagged
<br />Depletions
<br />Jeronimus Pit 15.00 0 0 0 15.00 15.91 0 15.91
<br />Hazeltine Pit 0 0 0 0 0 3.26 76.63 79.89
<br />Brighton Pit 13.67 0 0 0 13.67 15.40 2.90 18.29
<br />Tucson South Pit 5.47 0 0 0 5.47 5.47 0 5.47
<br />Wattenberg Pit 14.65 64.52
<br />(2,192,161 tons) 1.98 0 81.15 83.65 25.60c 109.26
<br />Platte Valley Pit 200.43 0 12.36 6.73 219.52 219.39 0 219.73
<br />Distel Pit 0a 0 1.54 0 1.54 1.59 0.09 1.68
<br />Tull Pit 2.58 26.99
<br />(916,876 tons) 0.99 0 30.56 16.55 0d 16.52
<br />W.W. Farms Pit 100.44 0 0.99 2.30 103.73 105.35 0d 105.25
<br />F-Street Pit 71.79 0 0 0 71.79 71.79 0 71.79
<br />Total -- -- -- -- 542.43 -- -- 643.79
<br />a Evaporation is replaced by the City of Longmont under their augmentation plan decreed in water court case no. 09CW271.
<br />b Lagged Dewatering Depletions, as shown in the table, are from past dewatering operations that have ceased but continue
<br />to impact the stream system.
<br />c Lagged dewatering depletions are from a temporary cessation of dewatering operations that occurred in January 2018.
<br />d So long as the pit is continuously dewatered, the water returned to the stream system is considered to be adequate to
<br />offset depletions attributable to the dewatering.
<br />A stream depletion model using either the Glover method, or Stream Depletion Factor (SDF)
<br />method was used to calculate the lagged depletions to the river. The Glover method uses four
<br />aquifer input parameters for each site as follows: 1) X - distance (ft) from centroid of exposed
<br />ground water to river, 2) W - distance (ft) from the aquifer boundary through the well to the river
<br />channel, 3) T - transmissivity of the alluvial aquifer (in gallons per day per foot) between the well
<br />and the river, and 4) S - specific yield (0.2 was used for all wells). The parameters used in the model
<br />for each site are listed in Table D below.
<br />Table D – Aquifer Characteristics
<br />Site Name T (gal/day/ft) X (ft) W (ft) SDF (days)
<br />Jeronimus Pit 100,000 1,600 23,000 -
<br />Hazeltine Pit 100,000 1,200 23,000 -
<br />Brighton Pit - - - 10
<br />Tucson South Pit 75,000 1,600 4,600 -
<br />Wattenberg Pit 80,000 1,200 5,500 -
<br />Platte Valley Pit 150,000 1,400 7,400 -
<br />Distel Pit 50,000 700 5,300 -
<br />Tull Pit 50,000 4,900 9,300 -
<br />W.W. Farms Pit 120,000 900 8,750 -
<br />F-Street Pit 120,000 2,600 5,000 -
<br /> The consumptive use and lagged stream depletions from each site are summarized in the
<br />attached “South Platte Combined Substitute Supply Plan Accounting 2018” sheet.
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