We're dedicated to urban watersheds

and their ecology.



The Urban Watersheds Research Institute (Institute) is a Colorado based 501(3)(c) non-profit corporation created in 2005.  It is dedicated to the sustainable environment and water resources of urbanized and urbanizing communities.  Our focus is on water resources technology, its development and its transfer to practitioners and public in order to benefit the urban watersheds ecologies. The Institute is also a licensed State of Colorado charity, eligible for not only Federal tax exempt donations but also by the State of Colorado. The Institute focuses on achieving its goals through:

promoting research

conducting seminars, technical training classes and workshops

participating and helping to organize conferences

participating in various urban water resource related activities


Topics of most immediate concern to the Institute include:

Urban water resources,

Storm water system modeling technology,

Storm water quality and quantity management and design,

Floodplain management and flood damage mitigation,

Restoration of degraded rivers, streams, lakes and other receiving waters,

Urban ecology protection,

Community needs, including aesthetics and function,

Long-term economic sustainability.


We ask for your support of our mission by sharing your thoughts and ideas with us, attending our sponsored classes/seminars/workshops and other events.  We also appreciate any financial contributions you make to this Institute to help us pursue these goals.

You may contact us by email at info@uwtrshd.com.


Retired. Former Manager, Fresno Flood Control District, Fresno, CA


Vice President & Chief Scientist

Eastern Research Group, Inc.

Lexington, MA



Water Resources Engineering

Dallas, TX


Attorney at Law, Denver, CO


The Board of Advisors helps the Urban Watersheds Research Institute with its long-term planning and policy formulation. Its members volunteer their time without compensation. The Institute is grateful for the service and dedication of all the board members.


Professor Emeritus, Colorado State University, Ft. Collins, CO


Retired. Former President, Sellards and Grigg, Inc., Lakewood, CO


President, Wenk Associates, Denver, CO



Formally Manger of Master Planning, Urban Drainage and Flood Control District


University of Colorado Denver



Orlando, FL


The Board of Directors is responsible for the fiscal wellbeing of the Urban Watersheds Research Institute and the organization’s policies as a non-profit 501(3)(c) corporation and as a registered charity in the State of Colorado. All Directors serve on the UWRI Board without compensation.



Executive Director,
ational Association of Flood and Stormwater Management Agencies, Washington, DC



Wright Water Engineers, Inc.



Formally Executive Director of the Urban Drainage and Flood Control District


The Technical Steering Committee was established to help the Institute with its technical pursuits in training and research.  All Committee Members are licensed professional engineers and volunteer their time without compensation. The Institute is grateful for their service and dedication.

Front row: Jim Guo (Vice President UWRI), Amanullah Mommandi (Colorado Dept. of Transportation), Ken MacKenzie (UWRI Board Member), Besharah Najjar (PE, Adams County), Ben Urbonas (President UWRI), Andrew Earles, committee chair (Wright Water Engineers). Back row: Chris Carlson (City of Loveland), Scott Struck (GeoSytech), Mark Glidden (CH2HMill), Bill McCormick (City of Aurora), Basil Hamdan (PE, City of Fort Collins), Dan Bare (private consultant), Jim Wulliman (Muller Engineering Company), Robert Krehbiel (Matrix Engineering and representing CASFM), Shou-Ching “Eric” Hsu, P.E (Parsons Brinckerhoff), Saeed Farahmandi (City and County of Denver), Denny Welker (no longer member of committee). Members not shown in picture: Gerald Blackler, PE, PhD (Enginuity), Brad Robenstein (Douglas County), Jeannie Rossillon (Jefferson County)




Executive Director

Urban Drainage and Flood Control District

2018 Schedule of Continuing Education





Feb 15


Mar 29 & 30


   Apr 26 & 27
















































   May 10 & 11
   Jun 28 & 29







     Jul 26 & 27

     Aug 24

    SEP 20 & 21

   Oct 25 & 26











Overview of WQ Regulations and Compliance)

Regional Statistical Hydrology
Stormwater Detention Systems

Intro to EPANET Water Systems Distribution Model

Hydrology Using HEC HMS

FIRM Map Revisions and Maintenance

Selection & Design of Filtration BMPs/LIDs

Intro to EPANET Water Systems Distribution Model

Use of SWMM for Drainage Design and Planning




List of 7 Instuctors



Strasser & Grayman







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Most of these classes are sponsored in part by the Urban Drainage and Flood Control District which allows the Institute to reduce the registration fee for them.  In addition, member of the Colorado Association of Stormwater and Floodplain Managers (CASFM) and of the Rocky Mountains American Public Works Chapter (RM-APWA) receive an additional discount. Most classes, unless otherwise noted on the individual class description, in 2017 are held at the training facility of Leonard Rice Engineers, Inc. in Denver. Significant additional discounts are available for early registrations. In addtion, for all classes related to water distribution system, members of AWWA receive a sifnifican discount. 

For detailed information about each class just click on the class name which will take you to website containing full a description.

Refund Policy: Full refund will be made if class is canceled by the Institute. Full refund will be given, less an admistrative handling fee, if requested by the student more than 10 days before start of class. No refund will be given if requested by student 10, or fewer days before start of class. There is no time restriction to substitute another student for the one originally registered. The Institute is not responsible for any other costs.


Since 2005 the Institute has conducted and promoted research in support of finding sustainable stormwater runoff management practices.  Many of these have been done in partnership with the Urban Drainage and Flood Control District (UDFCD), a special regional government covering the Denver metropolitan and adjacent areas. The following is a list of most of these efforts:


  1. A $10,000 grant to UDFCD to help fund a $97,000 effort to develop whole life-cycle effectiveness of stormwater BMP's. The work is being performed by Colorado State University under an agreement with the District. Colorado State University is using the total amount of the funds as one of the local matches for a major research project funded by the Water Environment Research Foundation.
  2. A $10,000 grant to UDFCD to help fund a Phase I of a research project by University of Colorado Denver to determine what can be mixed with sand and in what proportions to produce more affordable plant growth media for rain gardens (bio-retention cells, porous landscape detention) that will sustain robust plant growth, maintain high stormwater infiltration rates and provide good water quality treatment. Emphasis is on materials that may come from urban waste streams such as high quality compost, shredded paper, etc.
  3. A $10,000 grant to UDFCD to help fund Phase II of the research project by the University of Colorado Denver described above. This phase begins to extend the research work to field installations.
  4. A $10,000 grant to UDFCD to fund phase III of the research project by University of Colorado Denver described above. This phase extends the field investigations.
  5. The Institute entered into agreement in 2011 with to UDFCD to contribute $15,000 towards research project to study on-site runoff storage for landscape irrigation use by property owner. The District will match this contribution and expects to increase its share in 2012. The study will investigate the performance, needs and economics of capturing runoff from building roofs for reuse as lawn sprinkling water in a semi-arid climate.
  6. With help and input from UDFCD, the Insitute develoedp a continuous simulation model to estimate water quality capture volume for the sizing of stormwater runoff BMP and LID facilities. In 2017 it released an updated version of the model.  
  7. The Institute continues to develop design and analysis aids for engineers to manage stormwater runoff and its impacts.  In addition, the Institute has used the whole-life effectiveness software and the BMP/LID sizing software to analyze the effectiveness, economics and whole-life costs of implementing various options for managing stormwater runoff in several regions of United States.
  8. In 2014 partnered with UDFCD to fund the completion of a Pathogens in Stormwater report by the Urban Water Resources Council of the Environment and Water Resources Institute of ASCE. This funding permitted the completion of this very state-of-the-practice report that was in progress for several years and is now available through ASCE.

Links to Related Professional Organizations,
Conferences, Activities, and Items of Interest:

Papers Resulting from UWRI's Research Funding and Activities:


The software on this page is available for downloading at no charge.  Please be aware of the DISCLAIMER language that you agree with when you install and use any and all software and products available from Urban Watersheds Research Institute (UWRI). To help us continue with the development of user oriented software and other products in the field of stormwater management and the management of urban watersheds, we ask you to make a donation by sending us a check made out to UWRI, at mailing address: Urban Watersheds Research Institute, 3225 Summer Wind Ln., #2308, Highlands Ranch, Colorado, USA

WQ-COSM Version 2.0 User Manual (2013-04) PDF, 260KB

Water Quality Capture Optimization and Statistic Model WQ-COSM_v2.0 (2013-04) ZIP of the MSI, User Manual, Spreadsheet Files, 1.9MB

Description of the WQ-COSM Computer Model to Generate a Water Quality Capture Volume for Stormwater BMPs, Ben Urbonas, James C.Y. Guo and Ken MacKenzie 2011 (PDF 511 KB)

Blackler, G. and Guo, James C.Y.(2013).  Paved Area Reduction Factors under Temporally Varied Rainfall and Infiltration, ASCE Journal of Irrigation and Drainage Engineering, Vol. 139, No. 2, February 1, 2013.

Blackler, G. and Guo, James C.Y., (2012). Field Test of Paved Area Reduction Factors using a Storm Water Management Model and Water Quality Test Site, Vol. 17, No. 8, Journal of Irrigation and Drainage Engineering, © ASCE, ISSN 0733-9437/(0). IRENG-6569, August.

Guo, James C. Y. Cheng, Jeff, Wright, L.(2012).  Field Test on Conversion of Natural Watershed into Kinematic Wave Rectangular Planes, ASCE J. of Hydrologic Engineering, Vol. 17, No. 8, August.

Kocman, S. M.,Guo, J. C.Y. and Ramaswami A. (2012). Waste- Incorporated Subbase for Porous Landscape Detention Basin Design, ASCE Journal of Environmental Engineering, doi:10.1061/(ASCE)EE.1943-7870.0000391

Guo, James C.Y., Blackler, E G, Earles, A, and MacKenzie, K (2010).  Effective Imperviousness as Incentive Index for Stormwater LID Designs, ASCE J. of Irrigation and Drainage Engineering, Vol 136, No12, Dec.

Guo, James C.Y., Kocman, S and Ramaswami, A (2009).  Design of Two-layered Porous Landscaping LID Basin, ASCE J. of Environ Engineering, Vol 145, Vol 12, December.

Guo, James C.Y. and Urbonas, B. (2009).  Conversion of Natural Watershed to Kinematic Wave Cascading Plane,  ASCE J. of Hydrologic Engineering, Vol 14, No. 8, August.

Other Papers Involving UWRI's Participation
or of Professional Interest

Breaking Down the Barriers to Low Impact Development in Colorado, Andrew Earles, Derek Rapp, Jane Clary, and Janice Lopitz, 2008

Blue-Green Fingerprints in the City of Malmö, Sweden, Peter Stahre, June 2008

Using Rainwater to Grow Livable Communities, Sustainable Stormwater Best Management Practices (BMPs) by Water Environment Research Foundation

Can Stormwater BMPs Remove Bacteria? Jane Clary, Jonathan Jones, Ben Urbonas, Marcus Quigley, Eric Strecker, and Todd Wagner, 2008 (PDF, 229KB)

Full Spectrum Detention to Control Stormwater Runoff, Ben Urbonas and James Wulliman, 2007 (PDF, 88.4 KB)

Stormwater Runoff Modeling; Is it as Accurate as We Think? Ben Urbonas, 2007 (PDF, 397KB)

Full Spectrum Detention 2005-01-01 Concept Paper, James Wulliman and Ben Urbonas, 2005 (PDF, 260KB)

Learning from Nature: Reducing Urban Stormwater Impacts, James Wulliman and Paul Thomas, 2005 (PDF 4.7 MB)

Stormwater Wetlands and Wet Ponds on How to Keep Mosquito Populations at Bay William, F. Hunt, 2005 (PDF, 189KB)

Stormwater Best Management Practices, Mosquitoes and West Nile Virus, Monte Deatrich and Warren S. Brown, Tri-County Health Department, 2004 (PDF, 517KB)

Effectiveness of BMPs in Semi-Arid Climates, Ben Urbonas, 2003 (PDF, 401KB)

Observation on Atmospheric Dust Fallout in Denver, Ben Urbonas and John Doerfer, 2003 (PDF, 236KB)

Stream Protection in Urban Watersheds Through Master Planning, Ben Urbonas and John Doerfer, 2003 (PDF, 311KB)

Stormwater Sand Filter Sizing and Design - A Unit Operation Approach, Ben Urbonas, 2002 (PDF, 132KB)

Overflow Risk Analysis For Storm Water Quality Control Basins, James C.Y. Guo, 2000, (PDF, 444KB)

Synthetic Runoff Capture and Delivery Curves For Storm Water Quality Control Designs, James C.Y. Guo and Ben Urbonas, 2000 (PDF, 546KB)

Parameters to Report with BMP Monitoring Data, Urbonas, 1994 (PDF, 844KB)

Synthetic Runoff Capture and Delivery Curves For Storm Water Quality Control Designs, James C.Y. Guo and Ben Urbonas, 2000 (PDF, 546KB)

Two Decades of Stormwater Management Evolution – Presented in Brazil, Ben Urbonas 1999 (PDF, 1.35MB)

Design of Low Tailwater Riprap Basins For Storm Sewer Pipe Outlets, Michael A. Stevens and Ben Urbonas, 1996 (PDF, 283KB)

Finding a "Maximized" Water Quality Capture Volume by Runoff Capture Ratio, J.C.Y Guo, and Ben Urbonas , 1994 (PDF, 726KB)

Stormwater BMPS and Technology, Ben Urbonas, 1993 (PDF, 175KB)

Effect of Raingage Density on Runoff Simulation Modeling, Ben Urbonas, Michael Paul Jansekok and James C.Y. Guo, 1990. (PDF, 1.2 MB)

Sizing A Capture Volume for Stormwater Quality Enhancement,  1989 (PDF, 166KB)

Potential Effectiveness of Detention Policies, Ben Urbonas and Mark Glidden, 1981 (PDF, 165KB)

Reliability of Design Storms in Modeling, Ben Urbonas, 1979 (PDF, 665KB)


Between 2005 and 2008 the Urban Watersheds Research Institute has provided each year two $2,000 college scholarships to undergraduate engineering students at accredited Colorado Universities and between 2009 and 2012 two $2,500 scholarships. These were awarded through the Stormwater and Floodplain Managers’ (CASFM) and the American Public Works Association (APWA), Colorado Chapter’s scholarship committees. The awarding of these scholarships has been temporarily suspended due to other demands on the Institute’s fiscal resources.