2015-09-22_HYDROLOGY - M1986079 - Laserfiche WebLink

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Rick Parsons MEtG SWSP September 17, 2015 Page 2 of 8 continue backfilling the site, this SWSP covers the expected depletions assuming the exposed acreage does not grow or shrink in size. Submitted accounting will track the actual exposed acreage and replacements wilt be made accordingly. Depletions Gravel pit mining operations have resulted in a water exposure of 20.83 acres. All water surface area is exposed ground water and there are no areas exposed due to mining activities prior to 1981. The only loss now associated with the gravel pit is evaporative tosses. Gross evaporation at this site is estimated to be 43.9 inches per year based on NOAA NWS -33. Effective precipitation is estimated at 70% of the average monthly precipitation recorded at NOAA Brighton 1 NE climate station and is estimated to be 9.8 inches per year. The anticipated consumptive use for this plan is 59.19 acre-feet for the 20.83 acres of exposed water surface. Because depletions from this site do not impact the river instantaneously the applicant's consultant lagged the depletions to the South Platte River using the Integrated Decision Support group's Alluvial Water Accounting System (IDS AWAS) stream depletion model with the following assumptions: • Distance from the centroid to the river (X) = 1,500 feet • Alluvial aquifer width (W) = 18,500 feet • Transmissivity (T) = 100,000 gallons per day per foot • Specific Yield (S) = 0.2 The stream depletion model shows the stream depletions to hit the river during this SWSP approval period to be 61.82 acre-feet from April 2015 through March 2015. Monthly breakdowns of the lagged depletions are shown in Table 1 b. Replacement Depletions from the site will impact the South Platte River downstream of the Brantner Ditch headgate and upstream of the Brighton Ditch headgate. To make replacements during any time with a downstream call recorded at the Division 1 Office, the applicant has secured Fulton Irrigation Ditch Company (WDID 0200808) shares that will be diverted into the pit. The shares now under the Applicant's control were used on the Polly Mann property and the Tower property. A historical consumptive use (HCU) analysis was performed on these shares. Recharging the aquifer using these shares will allow for winter time replacements. Parkfield Partners, LLC owns 49 shares of the Fulton Irrigation Ditch Company (Stock Certificate No. 3905) which were historically used on the Potty Mann property. In total 150 Fulton Ditch shares were used by Frank Mann on the 133 acre property. The current ownership of those 150 ditch shares are summarized below. Parkfield Partners, LLC is another entity of the applicants Clay and Kent Carlson of Carlson Associates, Inc and Mann Resources, LLC. Clay Carlson has signed an affidavit on behalf of Parkfield Partners dedicating their 49 shares to this SWSP. Polly Mann Property Share Ownership Entity No. of Shares Change Case Parkfield Partners 49 SWSP 0202503 City of Brighton 96 OOCW202 South Adams County WSD 4 01 CW258 City of Thornton 1