Innovative Percolation Modeling for Floodplains

Innovation in traditional watershed modeling methods are necessary to address ever evolving risk assessment strategies for floodplains. With warming climates, storm events in coastal areas such as Florida are becoming more prevalent in frequency and intensity. This requires more sophisticated estimation of hydrological parameters used for calculating rainfall excess associated with storm events. Rapid transition in land uses that come with development also require a flexible approach to estimating rainfall excess which can then be responsive to changes in land cover characteristics. The authors have applied active percolation in modeling in a watershed project with significant areas of Type A hydrological group soils. Results indicate that models utilizing more physical based rainfall excess methods coupled with percolation in dry depressional areas and in dry retention pond systems results in a significant difference in floodplain extent where the soil conditions favor infiltration. These results are considered more reasonable and defensible, better reflecting observed conditions in these areas and more easily adaptable to future changes in land use.