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<br />1\ <br /> <br />2) "Water Surface Profile (HEC-2)," <br />Hydrologic Engineering Center, U. S. . <br />Army Corps of Engineers. <br /> <br />3) <br /> <br />"WSPRO, Bridge and <br />Computer Program," <br />Administration. <br /> <br />Hydraulic <br />Highway <br /> <br />Channel <br />Federal <br /> <br />b.. Alternative Methods. An alternative <br />hydraulic methodology may be accepted by <br />the Board provided it has been recommended <br />for general use by a governmental agency <br />or notable scientific body, is well <br />documented and is available to the general <br />user. In the case of a computer program. <br />documentation shall include a published <br />user's manual and a programmer's manual. <br /><;;;../,,~~~;(M;""( <br />4. -r19g9 Ele.:ati9M. Stream <br />~lge Y93P F'nn~ ~QRtours at <br />iRter:als C8rEea~9AdiBg Lv <br />_iaterval shall be shown on <br /> <br />'---.. <br /> <br />stationing aRE! <br />regular ~eEtieal' <br />lL~ map e6stSyr <br />the flooded area <br /> <br />maps. <br /> <br />5. BlockaQe. All culverts and bridges shall be <br />considered for the potential to become blocked <br />by floatiI\g debris. In determining if there . <br />is a potential for blockage, and subsequent <br />reduction in conveyance, old photographs, the <br />history of maintenance during high flows, <br />watershed characteristics such as erodibility <br />of channel banks, amount and type of <br />vegetation along stream, and size and <br />character of the waterway shall be <br />evaluated. Blockage may be accounted for in <br />computer runs by' increasing width of piers, <br />raising streambed elevation or reducing <br />waterway opening by a percentage. Where the <br />potential for blockage can be shown, human <br />intervention (e.g., snagging) shall be <br />considered only if such flood fighting <br />activities are specifically included in the <br />community's adopted emergency response plan. <br /> <br />6. RouQhness Coefficients. Values for the <br />roughness coefficient at valley cross sections <br />shall be based on assumed worst case <br />vegetation conditions along the stream and <br />floodplain. Past flood data, if available, <br />shall be used to verify the adopted roughness <br />coefficients, taking into consideration any <br />alteration in the channel subsequent to the <br /> <br />. <br /> <br />e <br />