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<br />The physical characteristics of watersheds need to be identified to adequately determine the <br /> <br />hydrologic aspects indigenous to the basin, The physical characteristics of streams include the <br /> <br />orientation, slope, channel width, vegetative cover, contributing area, and developed versus <br /> <br />undeveloped conditions, The shape and gradient of the basin can typically be characteristic of <br /> <br />specific regions of the state. Basin characteristics inc:lude criteria which establish slope values <br /> <br />as a classification tool for steep, moderate, and flat gradients for each basin, <br /> <br />Policv statement: It is expected that there will be variations in the CSM rates for Colorado <br /> <br />hydrologic investigations. These differences need to be qualified and documented in a <br /> <br />hydrologic analysis presentation. Currently available land-use planning documents are to <br /> <br />be considered for establishing developed vs. undeveloped conditions. The availability of <br /> <br />such documents can be determined from the local planning and zoning organization. Inthe <br /> <br />absence of documents projecting future watershed characteristics, the futurle basin <br /> <br />characteristics should be based on a nominal increase in impervious land areas over existing <br /> <br />conditions. <br /> <br />5.2 Flood Control Detention Storage Facilities <br />Drainage basins and their runoffs can be impacted by man-made detention facilities and naturally <br />occurring impoundments. The naturally occurring impoundments ate described as non-tributary <br />areas and are discussed under a separate element. Facilities or structures that retard mnoff may <br />be designed for flood control or incidental flood storage. <br />5.2.1 Allocated Flood Control Storage <br />Facilities which are designed for flood control have a level of flow reduction to be <br />considered during flood events, These facilities may be located either onsite or upstream <br />of the study area. To control a flood event these facilities must designated for flood <br />control and be under government control and have a responsible entity in charge of <br />maintenance and outlet works control and documentation, ~ <br />Policv statement: The level of flood flow reductions to be considered for government <br />owned/controlled is to be based on the operations of its outlet works and .level of <br />flood protection. Should the flood control level of these facilities be re-allocated, the <br /> <br />3 <br />