Common use of Model Methodology Clause in Contracts

Model Methodology. To develop an understanding of the behavior of the stormwater system, WilsonMiller used the recent version of the Advanced ICPR (ICPR) stormwater model. This tool has been verified for stormwater design and master plan uses throughout Florida. Runoff volume calculations are based on the Runoff Curve Number (CN) method. Hydrological soil group, defined by capacity to hold water, and ground cover conditions within a watershed are used to determine CN values, which, in turn, are used to estimate available soil storage capacity. Runoff volume is then calculated for a specified storm event based on rainfall depth and available soil storage capacity. The rainfall runoff relationship is based on the SCS method. Peak discharge calculations are based on the Graphical Peak Discharge method. The watershed CN, Time of Concentration (Tc), drainage area and rainfall depth are used to determine peak discharge for a specified storm event. The next step was the creation of a simplified numerical representation of the actual primary stormwater system. The primary stormwater management system model schematic is presented in Exhibit 3-4. The schematic shows the delineation of hydrologic units, the model nodes into which simulated runoff is input, conveyance channels and structures, as well as, the storage node. Identification numbers for various system elements are also shown on the schematic. The schematic provides a reference between the actual, physical location and the numerical model.