Judy A Horwatich
Over the last 20 years, Judy Horwatich aided local, state, and federal agencies determine the effects that rural and urban runoff has on the environment. Her early career concentrated on agricultural runoff to determine the effectiveness of best management practices on reducing sediment and nutrients to the streams. Her work now focuses measuring the quantity and quality of nonpoint source runoff in urban environments. Judy has assembled 30 years of local, state, and national urban runoff studies and incorporated them into the Source Loading and Management Model (SLAMM). She continues calibrate and verify this model concentrating on Wisconsin parameters. This effort allows Public and private engineers to use WinSLAMM to determine realistic pollution reduction credits for their area of concern. Her recent body of work includes evaluation of several proprietary and non-proprietary stormwater management practices that include hydrodynamic separators, stormwater filters, high-efficiency street cleaners, rain gardens, biofiltration cells and swales, grass swales, and filter strips.
B.S. in Civil and Environmental Engineering, University of Wisconsin-Madison, 1993
- Long-term calibration of Source Loading and Management Model (SLAMM) for the State of Wisconsin
- Evaluation of proprietary stormwater device that have been installed at various source areas
- Assessment of filtration and infiltration systems that were designed using the State of Wisconsin Technical standards
- Utilization of GIS to evaluate the relationship between landuse and water quality
Professional Licenses and Certifications
State of Wisconsin Professional Hydrologist
Science and Products
WinSLAMM (Source Loading And Management Model): An urban area nonpoint source water-quality model for Wisconsin
The WinSLAMM model is used to identify sources of pollutants in urban stormwater runoff and to evaluate management alternatives for reducing pollutants. USGS studies provide stormwater flow and pollutant-concentration data for calibrating and verifying WinSLAMM for use in Wisconsin.
The effect of particle size distribution on the design of urban stormwater control measures
An urban pollutant loading model was used to demonstrate how incorrect assumptions on the particle size distribution (PSD) in urban runoff can alter the design characteristics of stormwater control measures (SCMs) used to remove solids in stormwater. Field-measured PSD, although highly variable, is generally coarser than the widely-accepted PSD...Selbig, William R.; Fienen, Michael N.; Horwatich, Judy A.; Bannerman, Roger T.
Effects of best-management practices in Bower Creek in the East River priority watershed, Wisconsin, 1991-2009
Hydrologic and water-quality data were collected at Bower Creek during the periods before best-management practices (BMPs), and after BMPs were installed for evaluation of water-quality improvements. The monitoring was done between 1990 and 2009 with the pre-BMP period ending in July 1994 and the post-BMP period beginning in October 2006. BMPs...Corsi, Steven R.; Horwatich, Judy A.; Rutter, Troy D.; Bannerman, Roger T.
Parking lot runoff quality and treatment efficiencies of a hydrodynamic-settling device in Madison, Wisconsin, 2005-6
A hydrodynamic-settling device was installed in 2004 to treat stormwater runoff from a roof and parking lot located at the Water Utility Administration Building in Madison, Wis. The U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, the City of Madison, cities in the Waukesha Permit Group, Hydro...Horwatich, Judy A.; Bannerman, Roger T.
Highway-runoff quality, and treatment efficiencies of a hydrodynamic-settling device and a stormwater-filtration device in Milwaukee, Wisconsin
The treatment efficiencies of two prefabricated stormwater-treatment devices were tested at a freeway site in a high-density urban part of Milwaukee, Wisconsin. One treatment device is categorized as a hydrodynamic-settling device (HSD), which removes pollutants by sedimentation and flotation. The other treatment device is categorized as a...Horwatich, Judy A.; Bannerman, Roger T.; Pearson, Robert
Parking Lot Runoff Quality and Treatment Efficiency of a Stormwater-Filtration Device, Madison, Wisconsin, 2005-07
To evaluate the treatment efficiency of a stormwater-filtration device (SFD) for potential use at Wisconsin Department of Transportation (WisDOT) park-and-ride facilities, a SFD was installed at an employee parking lot in downtown Madison, Wisconsin. This type of parking lot was chosen for the test site because the constituent concentrations and...Horwatich, Judy A.; Bannerman, Roger T.
Water Quality, Hydrology, and Response to Changes in Phosphorus Loading of Nagawicka Lake, a Calcareous Lake in Waukesha County, Wisconsin
Nagawicka Lake is a 986-acre, usually mesotrophic, calcareous lake in southeastern Wisconsin. Because of concern over potential water-quality degradation of the lake associated with further development in its watershed, a study was conducted by the U.S. Geological Survey from 2002 to 2006 to describe the water quality and hydrology of the lake;...Garn, Herbert S.; Robertson, Dale M.; Rose, William J.; Goddard, Gerald L.; Horwatich, Judy A.
Effects of best-management practices in Otter Creek in the Sheboygan River Priority Watershed, Wisconsin, 1990-2002
The U.S. Geological Survey and the Wisconsin Department of Natural Resources began a comprehensive, multidisciplinary evaluation-monitoring program in 1989 to assess the effectiveness of the Wisconsin Nonpoint Source Program. Hydrologic, water-quality, habitat, and fish data were collected at Otter Creek from 1990 to 2002 with the pre-BMP (best-...Corsi, Steven R.; Walker, John F.; Wang, Lizhu; Horwatich, Judy A.; Bannerman, Roger T.
Effectiveness of a pressurized stormwater filtration system in Green Bay, Wisconsin: a study for the environmental technology verification program of the U.S. Environmental Protection Agency
A pressurized stormwater filtration system was installed in 1998 as a stormwater-treatment practice to treat runoff from a hospital rooftop and parking lot in Green Bay, Wisconsin. This type of filtration system has been installed in Florida citrus groves and sewage treatment plants around the United States; however, this installation is the first...Horwatich, J.A.; Corsi, Steven R.; Bannerman, Roger T.
Effects of best-management practices in the Black Earth Creek Priority Watershed, Wisconsin, 1984-98
The Wisconsin Department of Natural Resources and the U.S. Geological Survey began a comprehensive, multidisciplinary evaluation-monitoring program in 1989 to assess the effectiveness of the Wisconsin Nonpoint Source Program. Hydrologic and water-quality data were collected at Brewery and Garfoot Creeks in 1984 and 1985 (pre-best-management...Graczyk, David J.; Walker, John F.; Horwatich, J.A.; Bannerman, Roger T.
Influences of watershed, riparian-corridor, and reach-scale characteristics on aquatic biota in agricultural watersheds
Multivariate analyses and correlations revealed strong relations between watershed and riparian-corridor land cover, and reach-scale habitat versus fish and macroinvertebrate assemblages in 38 warmwater streams in eastern Wisconsin. Watersheds were dominated by agricultural use, and ranged in size from 9 to 71 km2. Watershed land cover was...Stewart, J.S.; Wang, L.; Lyons, J.; Horwatich, J.A.; Bannerman, R.
The SLAMM model is used to identify sources of pollutants in urban stormwater runoff and to evaluate management alternatives for reduce pollutants. These files provide stormwater flow and pollutant-concentration data for calibrating and verifying SLAMM for use in Wisconsin (WinSLAMM).