2021-08-17_HYDROLOGY - M2016085 - Laserfiche WebLink

Home Browse Search

NCCI Bennett Gravel Pit SWSP Page 3 of 6 August 17, 2021 offset evaporative and operational depletions under the SWSP. The net effect on the river from dewatering is shown in Table 3 (attached). Total Consumptive Use The total depletions at this site is estimated at 147.4 acre-feet for this SWSP period, which includes 21.8 acre-feet/year of net evaporative loss, 4.8 acre-feet/year of water used for dust control, 12.1 acre-feet/year of water lost with the mined product, and 108.6 acre-feet/year from dewatering. The IDS AWAS stream depletion model was used to determine the lagged depletions from evaporation and operational losses to the South Platte River. The aquifer characteristics used in the model for the alluvial well are: transmissivity (T) = 133,667 gallons per day per foot, specific yield (SY) = 0.2, the distance from the centroid of the gravel pit site to the stream = 1,136 feet, and the location of the parallel impermeable boundary was estimated to be 5,923 feet from the stream. The total lagged depletions for this SWSP period are 153 acre-feet, as shown in Table 3 (attached). Depletions from this operation will accrue to the South Platte River in the NE '/ of Section 12, Township 2 North, Range 66 West, 6tn P.M. Replacements Out-of-priority depletions associated with the mining operation at this site will be replaced using fully consumable water from the City of Fort Lupton ("City"). The fully consumable water will be released to the South Platte River from the City's Waste Water Treatment Plant ("WWTP") or water stored in Perry Pit. The attached Figure 2 shows the location of the WWTP and Perry Pit and the distances in miles to Bennett pit. Transit losses will be assessed at 0.5 percent per mile. The lease provides 96.1 acre-feet of replacement water March 1, 2021 through February 28, 2022, therefore this SWSP will expire on February 28, 2022. Conditions of Approval hereby approve the proposed SWSP in accordance with section 37-90-137(11), C.R.S. subject to the following conditions: 1. This SWSP is approved with the effective date of March 1, 2021 and shall be valid through February 28, 2022 unless otherwise revoked or superseded by a decree. If this plan is not decreed in water court by the SWSP expiration date, a renewal request must be submitted to this office with the statutory fee of $257 no later than December 1, 2022. If a renewal request is received after the expiration date of this plan, it may be considered a request for a new SWSP, in which case a $1,593 filing fee will apply. 2. Well Permit 83515-F has been issued for this pit, and this permit remains valid. The permit allows the use of groundwater for pond evaporation, dewatering, dust suppression, and water lost with mined product. The permit covers up to 11.0 acres of exposed surface area. The average annual amount of groundwater to be appropriated shall not exceed 93.1 acre-feet. Actual depletions cannot exceed these amounts and are limited to those uses specifically approved through this SWSP.