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Aggregate Industries South Platte Combined SWSP January 30, 2019
<br />Plan IDs 3614, 4773, 3624, 4772, 4616, 3437, 3376, 3650, 3668, and 5475 Page 6 of 21
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<br />A stream depletion model using either the Glover method, or Stream Depletion Factor (SDF)
<br />method (for the Brighton Pit) was used to calculate the lagged depletions to the river. The Glover
<br />method uses four aquifer input parameters for each site as follows: 1) X - distance (ft) from centroid
<br />of exposed groundwater to river, 2) W - distance (ft) from the aquifer boundary through the well to
<br />the river channel, 3) T - transmissivity of the alluvial aquifer (in gallons per day per foot) between
<br />the well and the river, and 4) S - specific yield (0.2 was used for all wells). The parameters used in
<br />the model 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 2019” sheet.
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<br />Replacements
<br />Lower Poudre River
<br />Replacement Sources
<br />Projected
<br />2019 Yield
<br />(acre-feet)
<br />Comments
<br />Whitney Ditch 174.45 13.5 shares
<br />Bucklen Pit 61.83 Annual lease of excess augmentation credit
<br />Greeley Irrigation Company 39.56 Lease of 3 shares
<br />Note: Projected 2019 yield may vary from previous estimates of net yields due to the computed return flow
<br />obligations based on the previous year’s actual water deliveries.
<br />Whitney Ditch
<br />Aggregate owns a total of 13.5 shares in the Whitney Ditch Company. The subject 13.5 shares
<br />were changed in case no. 90CW23 from irrigation use to industrial mining, dust suppression,
<br />reclamation, irrigation, augmentation under the plan for augmentation described in the decree, and
<br />piscatorial purposes. The use of the subject shares for replacement purposes in this SWSP was not
<br />decreed in case no. 90CW23; however, the Applicant has proposed to use the subject shares for
<br />replacement purposes pursuant to this SWSP in conformity with the requirements of case no.
<br />90CW23.
<br />The decree entered in case no. 90CW23 relied on a ditch-wide analysis of the Whitney Ditch
<br />developed for and decreed in case no. 08CW65. Based on a study period of 1950 through 1995, the
<br />Court found that the average annual gross river diversion was 10,600.2 acre-feet per year or 33.13
<br />acre-feet per share. The ditch-wide analysis determined that the overall average consumptive use
<br />was 4,400.9 acre-feet per year or 13.75 acre-feet per share for 320 shares, assuming a system loss of
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