2012-12-04_HYDROLOGY - M1986079 - Laserfiche WebLink

Home Browse Search

Rick Parsons M &G SWSP December 3, 2012 Page 2of5 Depletions Gravel pit mining operations have resulted in a water exposure of 27.57 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 losses. 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. 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 44.79 acre -feet. 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 head gate and upstream of the Brighton Ditch head gate. 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 for irrigation season replacements and a lease of reusable effluent from the Greeley WWTP (WDID 0302312) for winter time replacements. August 2012 - October 2012 Platte River Farms owns 12 shares of Fulton Irrigation Ditch Company stock (Certificate No. 3157) and has dedicated those shares to this plan. Additionally 39 shares of Fulton Irrigation Ditch Company stock owned by Maxine Tower have been leased by the applicant for use in this plan for the remainder of the 2012 water year. It is anticipated these same 39 shares will be leased for the 2013 water year as well. These 51 shares were historically used to irrigate properties near Brighton Road and E -470 approximately three miles north of the M &G pit. These properties have been dried up as a result of a mining operation that completed prior to 1981 and have since then been leased to other share holders in the interim. The Applicant has obtained a dry-up documentation for the shares owned by Parkfield Partners and by Maxine Towers which (1) documents the land to be dried up for August 2012 through October 2013, and (2) confirms these shares were not used for irrigation during the 2012 irrigation season, nor leased to others or used for other purposes during the 2012 irrigation season. Starting in August 2012 and for the remainder of the 2012 irrigation season, South Adams County Water and Sanitation District (SACWSD) is allowing the applicant to run the 51 shares controlled by the Applicant through their augmentation station located near 104 Ave (WDID 0202942). The SACWSD augmentation station discharges to the river at a point above the Brantner Ditch headgate. The Brantner is not reasonably expected to place a call and sweep the river for the remainder of the 2012 irrigation season. Therefore, the credits associated with the subject shares are expected to make it to the point of depletion directly west of the pit. The Applicant plans to rehabilitate the Fulton laterals serving the pit so that for the 2013 and future