Utilization of I-280 Highway Embankment as an Impounding Structure to provide a 93 Acre Recreation Lake Development : Black Hawk Creek: Sections 25 and 36, T78N, R2E, Scott County Iowa, Volume II: Hydrology and Hydraulic Studies, September 1966

(1966) Utilization of I-280 Highway Embankment as an Impounding Structure to provide a 93 Acre Recreation Lake Development : Black Hawk Creek: Sections 25 and 36, T78N, R2E, Scott County Iowa, Volume II: Hydrology and Hydraulic Studies, September 1966. Transportation, Department of

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Abstract

The general purpose of these studies is to determine the suitability of the area for one or more i mL1oundments, the capability of the watershed to support a recreational water surface area of the desired size, the flood potential of t he wat er shed, and t he hydraulic structures which will be required to convey flood discharges around or through the dams proposed in this recreational development. The impounding reservoirs must be capable of storing sufficient volume and holding a fairly constant water level to yield the desired water surface area needed to enhance but door recreation and permit uninterrupted use for water-borne sports. The valley soil s in each impoundment area must be sufficiently impervious to prevent undue see page and loss of water through the foundation of any proposed dam. The watershed should be of a size to yield sufficient runoff in drought periods to prevent undue lowering of the water surface from evaporation and transpiration processes. The flood potential of the watershed needs to be estimated in relation to downstream flood plain developments, the hazard posed to those developments by construction of a dam and impoundment, and the possible loss of investment in t he dam and appurtenant structures if rare, exceptionally severe floods do occur. Hydraulic structures must be designed to satisfy the assigned safety criteria, for the hazards involved. These problems will be studied in turn in this report.