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<br />Community Bulletin Page 3
<br />
<br />Gulch, These drawdowns are also likely not noticeable
<br />above the normal background fluctuations of ground wa-
<br />ter in the area,
<br />
<br />Upper South Park Aquifer
<br />Drawdowns in the Upper South Park Aquifer on the
<br />Sportsmen's Ranch gradually build over a 20 year period
<br />to an expected 300 to 500 feet. The drawdowns rapidly
<br />decrease to between five and 20 feet within two miles of
<br />the ranch, There are very few wells in the Upper South
<br />Park Aquifer near the Sportsmen's Ranch that could be
<br />affected,
<br />
<br />Lower South Park Aquifer
<br />Drawdowns in the Lower South Park Aquifer on the
<br />Sportsmen's Ranch gradually build over a 20 year period
<br />to an expected 300 and 800 feet. The wells with the
<br />highest drawdowns are confined by the Link Springs
<br />member of the South Park Formation-a confining layer
<br />that separates the Upper and Lower South Park Aquifers,
<br />The drawdowns rapidly decrease to about 60 feet within
<br />two miles of the ranch, ,Similarly, there are very few
<br />wells located in this aquifer near the Sportsmen's Ranch,
<br />
<br />Overall, only about a dozen wells in the South Park Ba-
<br />sin are likely to see any effects from pumping, Those
<br />impacts are restricted to the areas immediately adjoining
<br />the Park County Sportsmen's Ranch, The City of
<br />Aurora proposes terms and conditions to fully mitigate
<br />the impacts to these wells, A ground water monitoring
<br />network has been proposed to detect and measure poten-
<br />tial impacts of SPCUP operations before they reach a
<br />potentially affected area, Such monitoring can assist in
<br />the careful management of recharge and pumping to
<br />minimize impacts, Where there are impacts, typical
<br />mitigation ranges from payments to offset increased
<br />pumping costs, deepening or replacing a well, or provi-
<br />sion of a substitute water supply,
<br />
<br />Technical and economic feasibility of the SPCUP were
<br />determined based on the modeling, This report also ad-
<br />dresses Aurora's need for the project and its ability to
<br />integrate the project into its overall water supply system,
<br />The feasibility of the project is demonstrated through a
<br />number of surface hydrology, groundwater and engineer-
<br />ing investigations, These investigations evaluated the
<br />constructability of the various project facilities, cost of
<br />the facilities, operational effectiveness, and yield of the
<br />project in terms of the amount of groundwater pumped
<br />from the South Park Aquifers,
<br />
<br />Operational analyses and groundwater investigations indi-
<br />cate that the project could operate efficiently with as few
<br />as 12 wells with capacities of 1,000 gallons per minute
<br />each, The location of these 12 wells, as well as the other
<br />possible well sites and other Project facilities, are shown
<br />on (reverse side) Figure I, Additional wells could be re-
<br />quired pending the result of further field investigations,
<br />groundwater monitoring and groundwater modeling,
<br />
<br />The selected operational scenario requires the creation of
<br />an initial storage capacity of up to approximately 110,000
<br />acre-feet in the South Park Aquifers so that water from the
<br />recharge facilities would infiltrate into the South Park Aq-
<br />uifers, Once storage space in the aquifer is created, re-
<br />charge to the aquifers would balance pumping so that the
<br />average size of the cone of depression (drawdown) would
<br />not increase, This process would insure the long-term sus-
<br />tained yield of the project.
<br />
<br />SPCUP would be particularly effective in providing large
<br />drought year yields, The drought year yield of the project
<br />would be approximately 17,500 acre-feet per year;
<br />
<br />, Total project capital cosHsestimatedto be $39,784;000
<br />with a corresponding capital cost of$7,210 per acre-foot
<br />of average annual yield, The capital. c<;>st per acre-foot of
<br />firm yield would be approximately $4,140, Annual opera-
<br />tion, maintenance and replacement costs would be ap-
<br />proximately $120 per acre-foot.
<br />
<br />Overall, only about a dozen wells ill
<br />the South Park Basin are Iike(v to see
<br />allY effects from pumpillg, Those im-
<br />pacts are restricted to the areas im-
<br />mediately adjoinillg the Park COUII~V
<br />Sportsmen's Ranch.
<br />
<br />The final report in the latest series was an engineering
<br />analysis of the possible effects of an alternate place of
<br />storage of water rights decreed for storage in Columbine
<br />Reservoir to the South Park Formation was also recently
<br />completed, Analyses were performed of the operational
<br />scenarios comparing the original water right configuration
<br />
<br />Continued on page 8
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