Frequency Methodology for Evaluating Urban and Highway Storm-Water Quality Control Infiltration BMPs

Abstract

Time domain continuous simulation models using simple or detailed process models are routinely used to analyze storm-water control options. The interest in decentralized controls has generated the need to develop tools that can evaluate performance when response times are very short and may even be shorter than the available precipitation data. The effect of storage is much less in infiltration based systems so simpler frequency domain approaches can be useful. A simple, but reasonably reliable, model has been developed on the basis of system response time and frequency analysis using long-term precipitation data. In the model, the performance of a storm-water management facility is related to the loading rate of storm water onto the facility. Performance is estimated using long-term precipitation data, catchment information, and storm-water management facility specification. The developed frequency model provides a simple and relatively accurate way to estimate the overall performance of infiltration best management practices (BMPs) over a range of storm events. It can be calibrated using local field data and a more detailed time domain process simulator and then used to provide a macrolevel evaluation model that can be used to find the overall optimal control strategy.