Wet detention pond - Channel protection / water quality outlet configuration
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Design methodology
1-yr 24-hr "Kerplunk" (K124) 1-yr 24-hr routed (R124) 1/2 Pre-development 2-yr 24-hr peak "Kerplunk" (R224) 1/2 Pre-development 2-yr 24-hr peak routed (R224)
Orifice diameter (inches) 10.5 6.9 10.0 11.6
Oriface elevation (ft) 105.0 105.0 105.0 105.0
Surface area at orifice elevation (ac) 0.6 0.6 0.6 0.6
Peak discharge per design event (cfs) 6.4 2.1 5.8 5.8
Peak water elevation per design event (ft) 107.9 108.2 108.7 108.5

Note that the routed method for the 1-year design (R124) is much less than the kerplunk method (K124) due to the more constricted orifice.