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Statistics for simulating structural stormwater runoff best management practices (BMPs) with the Stochastic Empirical Loading and Dilution Model (SELDM)


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Granato, G.E., Medalie, Laura, and Spaetzel, A.B., 2021, Statistics for simulating structural stormwater runoff best management practices (BMPs) with the Stochastic Empirical Loading and Dilution Model (SELDM): U.S. Geological Survey data release,


This data release documents statistics for simulating structural stormwater runoff best management practices (BMPs) with the Stochastic Empirical Loading and Dilution Model (SELDM)(Granato, 2013). The U.S. Geological Survey (USGS) developed SELDM and the statistics documented in this report in cooperation with the Federal Highway Administration (FHWA) to indicate the risk for stormwater flows, concentrations, and loads to be above user-selected water-quality goals and the potential effectiveness of mitigation measures to reduce such risks. In SELDM, three treatment variables, hydrograph extension, runoff volume reduction, and water-quality treatment are modeled by using the trapezoidal distribution and the rank correlation with the [...]


Point of Contact :
Gregory E Granato
Originator :
Gregory E Granato, Laura Medalie, Alana B Spaetzel
Metadata Contact :
Gregory E Granato
Publisher :
U.S. Geological Survey
Distributor :
U.S. Geological Survey - ScienceBase
SDC Data Owner :
New England Water Science Center
USGS Mission Area :
Water Resources

Attached Files

Click on title to download individual files attached to this item.

“Hydrograph extension statistics in tab delimited format”
16.6 KB text/plain
“Volume reduction statistics in tab delimited format”
42.39 KB text/plain
“Water-quality ratio statistics in tab delimited format”
1.09 MB text/plain
“Minimum irreducible concentration statistics in tab delimited format”
622.89 KB text/plain
“Read me text file for SELDM import tables”
5.41 KB text/plain
“SELDM flow reduction and hydrograph extension import file see SELDMimportReadMe”
9.84 KB text/csv
“SELDM water-quality import file see SELDMimportReadMe.txt”
22.29 KB text/csv
“Microsoft Excel spreadsheet to calculate trapezoidal statistics”
42.34 KB application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
“Macro enabled Microsoft Excel spreadsheet to calculate water-quality ratios”
96.75 KB application/
“ASCII text metadata file”
9.29 KB text/plain


The purpose of this data release is to document the individual site statistics used by Granato and others (2021) to calculate BMP category statistics and to archive the spreadsheet tools used in those analyses. The individual site statistics also are provided so that analysts may use their own professional judgement to select statistics that are most representative of a particular site of interest. However, practitioners may need to combine statistics from multiple sites to represent a site of interest because sample sizes are small and monitoring artifacts are present in many BMP datasets and previous studies have not demonstrated predictive correlations between BMP design characteristics and BMP performance statistics.


These statistics were prepared by the U.S. Geological Survey (USGS) in cooperation with the U.S. Department of Transportation Federal Highway Administration (FHWA) Office of Project Development and Environmental Review. These Statistics were calculated by using version 1.2.0 of the Best Management Practices Statistical Estimator (BMPSE) (Granato, 2014; 2020) and the Microsoft Excel® spreadsheet tools FitTrapezoidToBMP01v1.0.3.xlsx and FitConcentrationRatiov1.1.0.xlsm. The data used for these analyses were derived from the December 2019 version of the International Stormwater BMP Database ( The International Stormwater BMP Database was developed by Wright Water Engineers, Inc. and Geosyntec Consultants for the Water Environment Research Foundation, the American Society of Civil Engineers/Environmental and Water Resources Institute, the American Public Works Association, the Federal Highway Administration, and U.S. Environmental Protection Agency. In some cases, however, the data used in this analysis are different from the data found in the December 2019 version of the International Stormwater BMP Database because the author worked closely with Jane Clary, the Project Manager of the BMP database to resolve a number of issues that were identified during the process for extracting, checking, and manipulating the data to do this analysis. The data were extracted from the International BMP Database and imported into the Best Management Practices Statistical Estimator (BMPSE) developed by Granato (2014). The statistics were calculated by using the source code that is documented within the BMPSE database (Granato, 2020). The USGS and the FHWA reserve the right to revise these statistics pursuant to further analysis and review. These statistics have been used by the USGS and is released on condition that the USGS or the FHWA may not be held liable for any damages resulting from their use. Information and numerical methods used in this study are attributable to the cited works. Copyright protection under Title 17 is not available for any work of the U.S. Government (17 USC §105).

Additional Information


Type Scheme Key
DOI doi:10.5066/P9X3ECTD

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