The town will normally accept two methods for hydrology computations, the Rational Method and the Clark Unit Hydrograph Method. The Rational Method may be applied to watersheds less than 160 acres in area where detailed hydrograph operations are not necessary. The Rational Method may be applied by use of hand computations or appropriate available computerized methods. The Clark Unit Hydrograph Method or the FLO-2D Method shall be applied for all watersheds greater than 160 acres in area, unless prior approval of an alternative method is received in writing from the Public Works Department. The COE HEC-1 Flood Hydrograph Package (1991) (HEC-1) is the preferred computer program for application of the Clark Unit Hydrograph Method. Other methods may be used, with prior written approval from the Public Works Department.
(Res. 1637, passed 2-28-02; Am. Res. 2871, passed 9-17-15; Am. Ord. 872, passed 9-17-15)