2013-11-22_HYDROLOGY - M1977560 - Laserfiche WebLink

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DIVISION OF WATER RESOURCES Paul Bruss November 20, 2013 Page 2 of 4 Evaporative depletions have been calculated using the maximum surface area of the pit, which is 29.9 acres. Depletions have been lagged back to the Arkansas River as requested in the previous SWSP approval letter., A Glover analysis was performed, using the following inputs: Distance from river: 2975 ft (evap.: measured from centroid Dewatering is measured from the edge of pit to river: 3726 feet (dewatering Pond 1) 3357 feet (dewatering Pond 2) 3203 feet (dewatering Pond 3) 2703 feet (dewatering Pond 4) Distance from alluvial boundary: 7675 ft (evaporation) 8126 ft (dewatering Pond 1) 7657 ft (dewatering Pond 2) 8203 ft (dewatering Pond 3) 8303 ft (dewatering Pond 4) Transmissivity: 71,000 gpd /ft Specific yield: 0.2 You have calculated the total lagged depletions to be 102.31 acre -feet (see attached Table 2). REPLACEMENTS Valco will continue to utilize a combination of leased water and historical ditch credits to make replacements to the river. Two new leases were obtained to provide replacement supplies during the 10 -month period of this SWSP from the Department of Corrections ( "DOC ") for 50 acre - feet and the Upper Arkansas Water Conservancy District ( "UAWCD ") for 50 acre -feet. Other replacement sources include Rocky Ford Ditch CU credits and any excess Canon City and Oil Creek ( "CC&OC ") ditch credits not used for replacement water supplies at Valco's Canon City East Pit. Conditions of Approval This substitute water supply plan is hereby approved pursuant to Section 37 -90- 137(11), C.R.S., subject to the following conditions: 1. This SWSP shall be valid for the period of June 1, 2013 through March 31, 2014, unless otherwise revoked, modified, or superseded by decree. Should an additional SWSP be requested, such renewal request must be submitted to this office with the statutory fee of $257 per gravel pit at least 45 days prior to the expiration date of this plan. 2. No more than 47.3 acres (29.9 acres of post -1981 exposure) of ground water may be exposed at the Rocky Ford East Pit during this plan year without first obtaining an amendment to the plan. The above acreage totals include any surface areas in ponds to which de- watering water is delivered. Documentation of pond sizes may be required by the Division Engineer in the form of an aerial photo evaluation or survey by a Professional Land Surveyor during the plan year 3. The Applicant must provide a copy of both lease /purchase agreements mentioned above to the State Engineer's Office and the Division Engineer as soon as possible.