C150016 feas study - Laserfiche WebLink

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A. Statement of Need for the Project 1. The City of Idaho Springs is undertaking this project to rehabilitate the Idaho Springs Reservoir Dam and to restore the storage capacity of the reservoir. 2. The original Idaho Springs Reservoir Dam is approximately 90 years old. Rehabilitation plans developed in 1976 were not completed. Repair plans developed in 1979 were not completed. The reservoir outlet valve was replaced in 1996/1997. 3. The Idaho Springs Reservoir, located on Chicago Creek, provides storage far reliable raw water supply to the City of Idaho Springs and the City service area. A map of the reservoir location and drainage area is included as Figure 1. 4. The Office of the State Engineer, Dam Safety Branch, has progressively restricted the capacity of the reservoir due to the deteriorated condition of the dam, evidence of seepage, and structural damage of the spillway. The most recent (June 1997) State Engineer's Report is included in Appendix 1. The Idaho Springs Reservoir is currently restricted to a water surface elevation 7 feet below the spillway crest. The Office of the State Engineer considers this the "safe storage level" based on existing conditions. The corresponding storage level (based on the Idaho Springs Reservoir Capacity Determination dated December 1996) is 120 acre feet (AF). The original storage capacity is a water surface elevation set at the spillway crest. The corresponding starage volume based on the Capacity Determination is 227 AF. The Capacity Determination is included in Appendix 2. Rehabilitation of the Idaho Springs Reservoir Dam is needed is provide downstream safety and to restore the water storage capacity of the structure. 5. Restoration of the water storage capacity of the Idaho Springs Reservoir will provide the City with potential additional income from water sales. B. Description of the Project Sponsor, and the Project Service Area 1. The City of Idaho Springs is a Statutory City formed in accordance with CRS 31- 1-203. The City is located in northeastern Clear Creek County, at the intersection of Interstate 70 and State Highway 103. 2. The service area for the City of Idaho Springs consists of the City and the residents of Soda Creek, Chicago Creek, Stanley Road, Virginia Canyon, and the Lowe property east of the City. The City also provides water for Clear Creek County Emergency Services for the immediate area of the City. 3. The City's existing raw water supply facilities consist of a raw water intake on Chicago Creek for supply to the water treatment plant. The City maintains treated water storage for 1 average day demand and emergency fire flow. The current restricted capacity of the Idaho Springs Reservoir provides for approximately 60 days of average demand.