WERF SELECT Model
Tool Download
The BMP SELECT Tool is made available to you at no cost as a result of WERF's open access policy. To download the tool, you must register with WERF's website and login. If you are logged-in, please click here to download the tool.
To receive updates to SELECT and other related news, please send an email to jmoeller@werf.org.
A wide array of different BMPs and LID practices are available for application on a developing watershed or for retrofit in developed areas. BMP choices are often based principally on minimizing the capital cost of installation of the BMPs.
SELECT is a simple planning level tool that enables a stormwater manager to examine the effectiveness of alternative scenarios for controlling stormwater pollution and the whole life cost associated with each scenario. Thus, the manager can make more informed decisions on which practices to permit with some confidence that they will meet imposed TMDL limits and also can have some confidence that the capital and O&M costs involved in implementing BMPs are known.
SELECT is encoded within an Excel 2003 spreadsheet, which means that it is intuitive and easy to use for most individuals. The control panel has several functional areas that guide users in setting defaults, inputting user information, and executing the model.
SELECT uses a long-term record of hourly rainfall to drive the model; this hourly rainfall is translated into runoff using a runoff coefficient that is related to the
effective imperviousness of the catchment. This runoff is introduced to the BMP. If there is capacity in the BMP, the runoff is captured; if the BMP is full, the runoff is discharged untreated to the receiving waters. The model calculates total outflow as the sum of what is treated and what is not. SELECT output data includes annual pollutant loads discharged to the receiving water, pollutant load frequency curves with uncertainty estimates, and an estimate of the whole life cost of the BMPs applied in the watershed. BMPs that can be simulated in SELECT include:
- Extended detention
- Bioretention
- Wetlands
- Swales
- Permeable pavement
- Filters
Water quality parameters that can be simulated include:
- TSS
- Total nitrogen
- Total phosphorus
- Total zinc
As time and funds permit, additional BMP and LID practices will be added to the model. If you would like to help expand the current set of BMPs or water quality parameters in the model, please contact Jeff Moeller at jmoeller@werf.org. We are in the process of developing a discussion forum to allow the user community to share feedback, tips, tricks, applications, and enhancement ideas for the tool. Coming soon: SELECT will be made available to the public in an open code format to allow the user community to make modifications and enhancements to the tool. WERF will establish a process to incorporate approved user community developed enhancements so that all may benefit. The latest information and updates on the tool will be posted at www.werf.org/select.