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<br />Page 41 <br /> <br />2, Runoff (developed) <br />a. Off-site + site for as many design points as requi red <br />1, Separate time of concentration (Tc) for each design <br />point (Rational Method) <br />2, Runoff coeff, or permeability coeff, from Table III <br />3, Existing drainage faciIi ties carrying flows - must <br />include flow for entire tributary area for each <br />design point <br />4, Irrigation ditch flows <br /> <br />3, Detention <br />a, Storage Volumes - 5 year and 100 year; Release Rates - <br />5-year and 100-year. <br />*b. Pond Outlet - Control Structures <br />1, Outlet control structure type <br />2, Use appropriate outlet discharge calculations <br />Include offsite flows <br />3. Consider head at entrance <br />4, Provide excess capacity for grates <br />5. Use restricter plate to reduce inlet area when neces- <br />sary <br />6, Compute outlet velocity and provide energy dissipator <br />if velocity exceeds maximum permissable channel <br />velocity <br />7. Check excess storm water passage effects <br /> <br />*c, Size outlet structures for parking areas <br /> <br />*d. Depths of ponding in parking areas, durations of storage <br />for each storm <br /> <br />*4, <br /> <br />Streets <br />'~a, Compute depths and velocity of flow, for initial & major <br />storm unless flow is less than that allowed by Figure 12, <br />Inlet capacities and depths at inlet, <br />Meet street standards in Table VII, <br /> <br />.c <br />"c. <br /> <br />'~b, <br /> <br />5, Open Channel Flow <br />a. Roughness coefficient <br />b, Trickle channel <br />c, Depth and velocity for initial and major storms <br />d, Channel protection <br />e. Minimum freeboard <br />*g, Hydraulic grade line <br /> <br />*6, Hydraulic Structures - pipes, culverts, inlets, etc, <br />a, Culvert capacity using standard nomographs (Fig 7 to 11) <br />b. Storm sewer capacity at each design section <br />c, Inlet capacity <br />d. Flow depth or headwater depth at inlet <br />e, Drops <br />f. Weirs <br />g. Streets, gutters, and crosspans <br />