From a forecasting perspective, accurate predictions of hydrograph characteristics such as peak magnitude (and volume), peak timing and channel overbank timing on the hydrograph rising limb are critically important. For timely termination of the issued alarm/warning, additional accuracy in the timing of receding flow falling below the overbank level is also desirable. Therefore, five basic hydrograph shape descriptors were considered: peak magnitude, peak volume, start timing, peak timing and end timing. Nonbasic shape descriptors considered included the “inflection” point dividing the hydrograph receding limb into nondriven quick and nondriven slow portions [Boyle et al., 2000]. This point was located using an approximate slope-change-based method, as the time-instant point on the receding limb with the maximum vertical depression from a line segment connecting the peak magnitude and peak end point