TMDL model description and overview
TMDL model description and overview
Link to this table
| Model | Model description | Applicability for Permit Compliance and Reporting |
|---|---|---|
| P8 | P8 is a physically-based water quality model which simulates the generation and transport of sediment and associated pollutants from urban watersheds. The model is capable of predicting sediment particulate removal of five (5) particle sizes (including one soluble fraction) and associated pollutants at a variety of BMP types. | P8 is an acceptable model for demonstrating compliance with TSS and TP WLAs. |
| MIDS calculator | The MIDS Calculator is an Excel-based stormwater quality tool used to estimate runoff and pollutant removal at a variety of stormwater BMPs. The model was originally developed by the MPCA to assist designers and regulators evaluate conformance to MIDS performance goals for development-scale models. The MIDS Calculator is an empirical model which predicts pollutant removal based on correlation to P8 results and design-standard BMP removal rates from literature. | MIDS calculator is an acceptable model for demonstrating compliance with annualized TSS and TP WLAs for simplified study areas. Specifically, the tool is limited in its ability to evaluate bypass from undersized BMPs and predict pollutant removal through non-volume reduction BMPs in series. |
| MPCA Simple Estimator | The MPCA Simple Estimator is a spreadsheet-based tool that utilizes the Simple Method to estimate land use based pollutant loading from urban watersheds. The empirically-based model estimates pollutant removal from nine (9) BMP types based on design-standard BMP removal rates from literature. | The MPCA Simple Estimator is an acceptable model for demonstrating compliance with annualized TSS and TP WLAs for simplified study areas. The tool is not capable of evaluating bypass from undersized BMPs or pollutant removal through BMPs in series. |
| WinSLAMM | WinSLAMM is a water quality model originally developed for the USGS to evaluate nonpoint pollution in urban areas. The model predicts pollutant loading from a variety of land use and impervious area types and calculates pollutant reduction at a variety of control devices (BMPs). Pollutant reduction at control devices is based both on experimental field results (empirical) and tracking of particulate settling and filtration (physically-based). | WinSLAMM is an acceptable model for demonstrating compliance with TSS and TP WLAs. |