Abstract:The RUNOFF block of EPA's storm water management model (SWMM) was used to simulate the quantity and quality of urban storm water runo from four relatively small sites (i.e. 5 . 97±23 . 56 ha) in South Florida, each with a speci®c predominant land use (i.e. low density residential, high density residential, highway and commercial). The objectives of the study were to test the applicability of this model in small subtropical urban catchments and provide modellers with a way to select appropriate input parameters to be used in planning studies. A total of 58 storm events, measured by the US Geological Survey (USGS), provided hyetographs, hydrographs and pollutant loadings for biological oxygen demand (BOD 5 ), total suspended solids (TSS), total Kjeldahl nitrogen (TKN) and lead (Pb), and were used for calibration of the model. Several other catchment characteristics, also measured or estimated by USGS, were used in model input preparation. Application of the model was done using the Green±Ampt equation for in®ltration loss computation, a pollutant accumulation equation using a power build-up equation dependent on the number of dry days, and a power wash-o equation dependent on the predicted runo rate. Calibrated quantity input parameters are presented and compared with suggested values in the literature. The impervious depression storage was generally found to be the most sensitive calibration parameter, followed by the Manning's roughness coecients of conduit and overland¯ow, the Green±Ampt in®ltration parameters and, ®nally, the pervious depression storage. Calibrated quality input parameters are presented in the form of regression equations, as a function of rainfall depth and the number of antecedent dry days. A total of 16 independent rainfall events were used for veri®cation of the model, which showed a good comparison with observed data for both hydrographs and pollutant loadings.

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Runoff depth and pollutant loading (Biological Oxygen Demand [BOD5], Total Suspended Solids [TSS], Total Kjeldahl Nitrogen [TKN] and lead [Pb]) computations of urban stormwater runoff from four small sites (i.e., 14.7–58.3 ac) in South Florida were performed using the Soil Conservation Service (SCS) hydrology method and empirical equations developed by the U.S. Environmental Protection Agency (EPA). Each site had different predominant land uses (i.e., low density residential, high density residential, highway and commercial). Quantity and quality data from 95 storm events at these sites were measured by the U.S. Geological Survey (USGS), and used for calibration of the methodology to derive appropriate input parameters. Calibrated input parameters were developed for each land use to test the applicability of the methodology in small sub‐tropical urban watersheds, and to provide hydrologists with a way to select appropriate parameter values for planning studies. A total of 16 independent rainfall events were used for verification of the methodology. Comparisons of predicted versus measured data for both hydrographs and pollutant loadings were performed.

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The Miami-Dade Water and Sewer Department (MDWASD) is the 5 th largest water and sewer utility in the United States. MDWASD, inclusive of the municipalities it serves, has a very complex wastewater collection and transmission system consisting of over 2000 pump stations, 1000 miles of force mains, and 4000 miles of gravity sewers. A Peak Flow Management Study, which includes the construction of a hydraulic computer model of this system, was mandated as part of an EPA settlement agreement. As part of this agreement, MDWASD was required to install supervisory Control and Data Acquisition (SCADA) telemetry on all of the pump stations it owns. Presently, SCADA is installed on 85% of the stations. MDWASD has recognized the benefit of SCADA as a long-term, data collection, system. This data proved useful when MDWASD reviewed major storm events during 1998 and 1999 to quantify rainfall dependent infiltration and inflow (RDII) and to determine the relationship between rainfall and RDII. This paper presents the MS Access application developed to quantify the individual pump station's RDII response. Spreadsheet applications were first employed but the volume of data overwhelmed the spreadsheet capacity. MS Access was chosen because of its availability and ease of use. Novice MS Access users can implement this application and customize it at will. Once RDII is quantified in a digital database format, a myriad of relationships can be developed. The biggest advantage to this application to the engineering community is that the RDII can be quantified, related to rainfall, and documented for pre-and post-rehabilitation analyses.