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M-2001-107 - NCCI Pit #1, 112 (c) Amendment Application Adequacy Review 01 Response, 1113012007 -2- Case 2 - Lined water storage reservoir with no surface diversions other than precipitation and evaporation. The approximate water balance for a lined water storage reservoir was found to be the following: • Groundwater inflow: 27 gpm • Groundwater outflow: 0 gpm • Precipitation: 70 gpm • Evaporation: 97 gpm In this case the reservoir would experience a net loss of 213 ac-ft per year and would be empty in approximately 11 years. It would then remain empty. Case 3 - Lined water storage reservoir with no surface diversions other than precipitation and evaporation, and a 100 foot long liner breach on the up gradient side of the reservoir. The approximate water balance for a lined water storage reservoir with liner breach was found to be the following: • Groundwater inflow: 96 gpm • Groundwater outflow: 0 gpm • Precipitation: 70 gpm • Evaporation: 166 gpm In this case the reservoir would experience a net loss of 102 ac-ft per year and would be empty in approximately 23 years. It would then remain empty. A steady state case with a liner breach occurring on the down gradient side of the reservoir was not estimated because during this case the reservoir would remain virtually empty because of the small amount of inflow through the liner and due to precipitation, with a relatively large outflow due to evaporation and into the groundwater aquifer through the liner breach. The actual operation of the proposed lined water storage reservoir will not fall into one of the 3 steady state cases shown above. The reservoir will be operated as either an exchange or augmentation water storage reservoir. This indicates that when the end user either removes water from the river at an upstream location, or causes a depletion to the river's normal recharge flows at an upstream location, they will remove water from the reservoir and return it to the river to offset the upstream effects to the river. The water removed from the reservoir is then replaced when the water rights along the river permit. It is estimated that during normal operations of the reservoir a minimum of one-half to the entire reservoir storage volume will be removed and replaced during the course of one year's operation. Because one-half to the entire volume of water stored in the reservoir is replaced each year, it is not likely that evapoconcentration will be a concern. Also, should a liner breach occur, the breach will be immediately repaired to maintain the impervious barrier around the perimeter of the reservoir. Rule 4 Performance Warranties and Financial Warranties 1) The Division is in the process of evaluation the adequacy of the proposed Financial Warranty, and will advise Applicant if any changes are needed as soon as our evaluation is complete. NCCI will address any questions or comments the Division has regarding the proposed financial warranty when they are received. 4:1 1400 W 122"d Avenue - Suite 120 • Westminster CO 80234 - Ph: 303-457-0735 - Fax: 303-920-0343