Table 4.1 below in Table 14.4 (MSMA, 2000) gives the recommended loss models for used in the Time-Area Method.
Table 4.1: Table 14.4 (MSMA, 2000)Recommended Loss Models and Values for Hydrograph
Note: Hydrological Soil Group corresponds to the classification given by the U.S Soil Conservation Service. Well drained sandy soils are “A”; poorly drained clayey soils are “D”. The texture of the layer of least hydraulic conductivity in the soil profile should be considered. Caution should be used in applying values from the above table to sandy soils (Group A).