- WinSLAMM Version 10.3.4 released!
- Credit cards now accepted for software purchase (posted 12/5/2017)
- ArcSLAMM and ArcSLAMM+ are available! ArcSLAMM can be
accessed via the
University of Northern Iowa's GeoTREE Center website. GeoTREE
ArcSLAMM+ is available here.
- Regional parameter files (for most of North America) and
additional standard land use
files updated. See the Select
Documentation page for details. (posted 10/31/2012).
PV & Associates, LLC is a small business that develops
water quality software program — WinSLAMM.
The program is continually updated as new research data
The program was originally developed as outgrowths of early
stormwater research conducted during the 1970s for the US EPA and
other agencies. We
realized that the monitored data did not correspond to many assumptions
that were the basis for available stormwater quality models, and
therefore decided to create a program that better reflected
research results and was more focused on stormwater quality management
than on drainage design.
is supported through software sales and has also
been supported by organizations such as the Environmental
Protection Agency (EPA), Ontario Ministry of the Environment,
Environment Canada, Wisconsin Department of Natural Resources (WDNR)
and the United States Geological Survey (USGS). For a complete
list of organizations that have supported model development, see the
WinSLAMM History page on this website.
Current Release: v 10.3.4
WinSLAMM (Source Loading and Management Model for Windows) is the only
Urban Stormwater Quality Model that evaluates runoff volume and
pollution loading for each source area within each land use for each
rainfall event. It does not lump impervious areas together nor
does it lump all the areas in a single land use together.
Evaluation at the source area level allows stormwater quality
professionals the ability to target the highest loading areas and
recommend improvements to reduce runoff volume and pollution loading
from those areas.
WinSLAMM is the leading model for evaluating LID Practices and Green
Infrastructure. USEPA's definition of Green Infrastructure is "systems and practices that use or mimic
natural processes to infiltrate, evapotranspirate (the return of water
to the atmosphere either through evaporation or by plants), or reuse
stormwater or runoff on the site where it is generated."
WinSLAMM the only model that evaluates stormwater pollution at the
source area level - were runoff is generated.
WinSLAMM utilizes small storm hydrology - the concept that the
majority of the runoff volume and pollutant loadings in urban areas is
a result of the small and medium rainfall events.
WinSLAMM can model a growing list of stormwater control measures
including infiltration/biofiltration basins, street cleaning, wet
ponds, grass swales, filter strips, porous pavement, catchbasins,
water reuse, and various
WinSLAMM can be used to answer questions such as:
- How effective are stormwater control
reducing runoff and pollutant loadings?
- What are the most cost-effective solutions for meeting urban
stormwater quality objectives?
- What type of, and how big should, stormwater control measures be?
Since its origination in the 1970’s, the
program’s use has extended across North America and overseas.
WinSLAMM is based largely upon Dr. Robert Pitt’s
studies conducted in the United States and Canada and by research
studies conducted through the WDNR and the
Various practitioners, municipalities, and watershed groups at the
regional and local level have used WinSLAMM to address a variety of
urban stormwater issues:
- Developing TMDL implementation plans
- Identifying management practices to achieve pollutant reductions
under a municipal separate storm sewer system (MS4) stormwater permit
- Determining optimal green infrastructure strategies for reducing
volume and peak flows to combined sewer systems
- Evaluating site specific post-construction stormwater management
- Developing a phased BMP installation plan using the cost
Because the majority of WinSLAMM development is not funded by grants,
the improvements and support do not stop when the grant runs out.
This means the user will always have access to help when its