About CHI


Since 1978, Computational Hydraulics International (CHI) has developed, marketed and supported technically advanced, professional software systems for stormwater management, wastewater and watershed modeling. PCSWMM, our main software offering, has been the trusted spatial decision support system for US EPA SWMM for over 35 years. PCSWMM is flexible, scalable, powerful and affordable, offering high value at an economically sensible price.

Devoted to developing solutions that result in bettering the quality of life through better drainage and water quality improvement, CHI’s innovative technology offers engineers the tools to analyze flooding and facilitate responsible urban and natural drainage planning and design. Our solutions are easily attainable and implemented globally, promoting healthier communities, sustained ecosystems, increased bio-diversity and reduced environmental impact.

CHI is staffed by professional engineers, seasoned educators and software industry professionals armed with a wealth of industry knowledge and application development history. Highly committed to future technology development, CHI continually collaborates with our clients to perpetually improve our technology and develop new applications. Our workshops, annual International Conference on Water Management Modeling (ICWMM) and the papers presented therein are great sources for industry information transfer. Our list serve forums and blog are also excellent networks for free idea exchange. As part of our mandate to continue the development of innovative modeling tools and techniques, CHI's staff have published over 200 technical papers on urban drainage.

Licensed under the Professional Engineers of Ontario, CHI is recognized internationally and has a solid reputation for providing our clients with quality engineering and professional model review services. Computational Hydraulics International integrates experience, knowledge and innovation to ensure efficiency and accuracy, saving our clients time and money.

Understanding a consulting engineer’s point of view, our software provides smart solutions designed to improve collaboration, streamline workflow, reduce project time and save resources, empowering consulting engineering firms to be more competitive, more productive and win more projects.

Backed by partners in the U.S.A., Canada, France, China, Singapore and South Africa, CHI takes pride in delivering professional excellence in innovative technology solutions, trusted consulting engineering services, superior support and better educational services. Our technology is used by more than 5,000 clients, has been successfully applied in over 10,000 projects in more than 85 countries and is the preferred choice for major consulting engineering companies, large cities, conservation authorities and other government organizations throughout North America and around the globe.

Why Choose Us

  • Well established company
  • Staffed by professional engineers, seasoned educators and software industry professionals
  • Experienced, knowledgeable and reputable
  • Trusted in the industry
  • Innovative thinking
  • Technology leaders
  • Dedicated co-operators
  • Promote high standards of quality
  • Dedication to technology and service excellence
  • Committed to future product development

Why Choose Our Software

  • Intuitive, comprehensive systems
  • Accurate and reliable technology
  • Meets the needs of today's industry challenges
  • Customized solutions available to suit your requirements
  • Offers high value with economically sensible pricing
  • Provides a quick return on investment

Mission and Philosophy

Our Mission

CHI has been dedicated to the global development of healthier communities and ecosystems by providing and encouraging best water management software and practices. We feel that the quality of life is highly dependent on the quality of the local water environment. Our mission therefore, is to bring about better ecosystems and environmental planning, design, construction and management of water systems, by developing, distributing and supporting innovative software solutions that are easily attainable for many and can be used by the widest possible user community around the world.

Our Philosophy

CHI believes that urban water systems can be designed in a way that supports environmental goals rather than working against them. Our PCSWMM software technology offers engineers the tools to design urban water systems that are less invasive, less disruptive, closer to the intended natural hydrologic function, and thus encourage higher biodiversity. These tools not only facilitate responsible planning and design; they ultimately lead to healthier human communities.

Our fundamental drive is to expand our engineering concepts and technology from their strong foundation in Newtonian physics to include and embrace Darwinian principles. We believe that the design of sympathetic water systems greatly impacts the quality of life for humankind and all nature. Using intelligent modeling, planners, engineers, and managers can transform drainage infrastructure to create better communities. PCSWMM’s environmental and ecosystem sensibilities foster a wider biodiversity of plants and animals, and inevitably encourage the development of thriving human societies. CHI works with clients the world over to manage the development of water systems and drainage infrastructure through technological solutions that help integrate physical, biological and ecosystem data into very long-term sustainable environments.

Rather than confining thinking to just Newtonian physics, we believe that practitioners ought to direct their attention further up the hierarchy of concerns towards ecology and Darwinian principles. In this view, a sustainable drainage system is an environment supporting a diverse host of life-forms, which adjusts as the population mix evolves – and which ideally is designed to maximize bio-diversity. Planning such a system is challenging, and requires building more complex models that support wider bases for knowledge. For instance, we model the gamut of flow velocities, depths, temperature, pH, turbidity and chemicals and link to aquatic ecosystem models; at a minimum this certainly requires a philosophy of continuous modeling.

On the other hand, traditional engineering and its bedfellows have sought to minimize entropy, using methods that ultimately replace natural habitats with surfaces that are generally abiotic or worse. Changing a traditional mindset is an incredible challenge but we believe it can be well worth the effort. CHI will continue to develop solutions that ultimately result in reducing our impact on the world, bettering our environment and improving the quality of life for all.


Rob James, B.Sc.(Eng), P.Eng.

President & CEO

Rob James has worked for CHI for over 25 years, both as a software developer and as an engineer on a wide variety of urban and watershed drainage management projects. He has taught at over 100 workshops on PCSWMM and EPA SWMM and has headed the development of PCSWMM from its early PC-DOS days to the current PCSWMM releases.

William James, D.Sc., PhD., P.Eng

Founding President

Bill James, University Professor Emeritus of Engineering at the University of Guelph and the founding president of CHI, is an internationally recognized authority on stormwater runoff with over 50 years experience in research, teaching and consulting. He has published 20 books, over 200 technical papers and has presented professional courses throughout Canada, the U.S. and overseas. Dr. James has supported SWMM from its earliest distribution, developing the first PC version in 1984.

Capsule Resume

Recent CV

Influents Magazine (Winter 2014) interviews Bill James


In order to bring about better ecosystems and healthier communities through the improved planning, design, construction and management of water systems throughout the world, we understand the importance of developing partnerships.

When you partner with CHI, you take the right step towards improving the quality of the local water environment, and generating business success for you and your clients. For more information and/or to enquire about partnership opportunities, please email us at info@chiwater.com.


Located in Laval PQ, AquaVidya is a firm specializing in urban hydrology, stormwater modeling and water resources planning. The firm is renowned for its analyses of hydraulic problems, and has been involved in projects all over the world, from Northern Quebec to Costa-Rica, from Grenada to Algeria and from Western Africa to Russia.

AquaVidya provides training on PCSWMM and EPA SWMM5, has promoted the sale of our software for over 20 years and is a valued CHI partner.

AquaVidya contact:
Gilles Rivard (grivard@aquavidya.com)
Telephone: 1-450-689-2967
Website: www.aquavidya.com

cba Specialist Engineers

Located in Johannesbug, South Africa, cba Specialist Engineers operates as a centre of excellence, offering specialist services through the expertise of it's sole member, Chris Brooker, and through forming strategic alliances with like minded professional engineers.

Over the course of each year cba provides training on PCSWMM and EPA SWMM5 at multiple locations across South Africa.

cba Specialist Engineers contact:
Chris Brooker (cbrooker@iafrica.com)
Telephone: +27 (0) 11 465-0510
Website: www.cbaspecialisteng.co.za


Hydropraxis is a consulting company located in Montpellier, France. The organization specializes in sanitation and drinking water, flood risk management, environment and sustainable development, waste clean energy, alteration and restoration of rivers and civil engineering.

As a valued CHI partner, HydroPraxis distributes, supports and provides training for PCSWMM EU (an adapted version of PCSWMM) in Europe and French speaking countries around the world.

HydroPraxis contact:
Nelly Peyron (npeyron@hydropraxis.com)
Telephone: +336 79 42 05 70
Website: www.hydropraxis.com


Founded in 1999, Lonwin has been successful to provide engineering solutions and services in many water related industries.

CHI and Lonwin entered an official partnership in 2014. As the exclusive CHI partner in China, Lonwin promotes, distributes, trains and supports PCSWMM for the Chinese market.

Lonwin contact:
Shu Wang (shupcswmm@126.com)
Telephone: +86 022-24102119-8868
Website: www.pcswmm.cn

Onno Fortuin Consulting

Opening in 2008, Onno Fortuin Consulting located in Western Cape, South Africa specializes in Mining and Environmental Engineering. They provide consulting services with a focus on environmental and surface water engineering.

Since then they have had the opportunity to apply PCSWMM and EPA SWMM5 in a wide variety of advanced mine surface water modeling applications and help CHI conduct training sessions across South Africa.

Onno Fortuin Consulting contact:
Onno Fortuin (onno@consultme2.co.za)
Telephone: +27 (0) 53 831-1675


CHI is proud to serve the Canadian, US and International engineering community. Our mission to bring about better environmental planning, design, construction and management of urban drainage systems, through developing, distributing and supporting the best possible modeling software.

With clients ranging from the largest cities, multi-national corporations and government agencies to universities, local consulting firms and municipalities, we provide software and education services to thousands of clients in over 85 countries and on every continent.

CHI offers a friendly, creative and challenging work environment where each team member is appreciated. We understand that it is with the knowledge and hard work of our employees that we continue to grow and realize our goals.

If you are interested in a position with CHI, please send us your resume and references by e-mail to info@chiwater.com. Please note that only those candidates selected for an interview will be contacted.

CHI is an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race, colour, religion, sex, national origin, disability status, protected veteran status, or any other characteristic protected by law.

Full time Water Resources Engineer (or EIT)

CHI is seeking an enthusiastic individual to join our growing team of water resources engineers. Job duties and responsibilities will include:

  • Developing, running and analyzing EPA SWMM5 and PCSWMM models including 1D and 2D water quantity and quality modeling
  • Working with geospatial data in CAD and GIS systems
  • Working under the direction of a team of engineers and software developers
  • Providing engineering consulting services on a variety of projects, both in Canada and around the world
  • Report writing and preparing technical documentation
  • Assisting with water management modeling training and instruction, including webinars and workshops (both local and those involving travel)
  • Assisting with research and development, including technical research, and validation of new tools
  • Providing software support services, including answering technical questions, diagnosing and resolving problems with client models
  • Supporting other CHI activities and initiatives including, administrative duties, annual conference, journals, etc.

The ideal candidate will have the following qualifications:

  • Master’s degree in Civil/Environmental/Water Resources Engineering
  • 1-5 years of engineering experience
  • Practical experience using EPA SWMM5 and its related user interfaces
  • Experience using other modeling software (e.g., HEC-RAS)
  • Advanced computer skills, with proficiency in CAD and GIS applications
  • Excellent written and verbal communication skills
  • Ability to work independently as well as with a team
  • Competency and ability to work on multiple projects, resolve conflicting priorities, and complete assignments in a timely, efficient manner

The successful candidate will receive a competitive compensation package. This position will provide the following opportunities:

  • Gain experience in a wide variety of advanced stormwater, wastewater and watershed modeling applications using state-of-the-art modeling and analysis tools
  • Learn about leading edge methodologies and approaches to solving water resources problems and designing infrastructure that minimizes the environmental impacts of development
  • Work with a closely-knit team that is committed to collaborating with our clients and water resources professionals around the world to continually improve our technology and develop new applications
  • Ongoing professional development through conference attendance and training participation

Part time/Full time Web Developer

We have a Web Developer position available for someone with creativity and motivation.


  • Design, develop, expand and maintain CHI website


  • A computer science degree
  • At least 2 years programming experience
  • Experience with ASP.NET in C#, SQL server, Javascript, JQuery, CSS and HTML5
  • Ability to work independently as well as with a team

Health and Safety

CHI is committed to providing and maintaining a work environment which is safe and where risks to the health of its employees and visitors are minimized. In addition to promoting good practices in health and safety, CHI endeavours to create an environmentally-responsible workplace. Protection of both staff and the environment is a core value of CHI.

In fulfilling this commitment, CHI management will provide and maintain a safe and healthy work environment in accordance with industry standards and in compliance with legislative requirements, and will strive to eliminate any foreseeable hazards which may result in personal injury/illness, accidents, or property damage.

CHI recognizes that the responsibility for health and safety is shared. As such, all employees are equally responsible for identifying, assessing, and minimizing health and safety risks within the work environment, including:

  • taking reasonable care for their own safety and that of others who may be affected by their acts and omissions;
  • using office equipment and furniture safely;
  • undertaking only tasks for which appropriate authorization and/or training has been given;
  • co-operating with the management to ensure a healthy and safe workplace;
  • bringing to the immediate attention of the management any safety matters of concern;
  • reporting all accidents, incidents and workplace hazards;
  • following the appropriate fire and emergency procedures in the office building; and
  • taking due diligence during field/client visits, including travel to and from the field/client sites.

All CHI employees are required to understand their obligations, participate actively and take responsibility in order to maintain CHI's excellent health, safety, and environmental performance. With the cooperation of all staff, we can continue to enjoy a safe and healthy work environment.

Terms of Use

Welcome to CHI's family of websites (chiwater.com, pcswmm.com, icwmm.org, chijournal.org and openswmm.org). If you continue to browse and/or use these websites you are agreeing to comply with and be bound by the following terms and conditions of use which, together with our privacy policy, govern Computational Hydraulics Int.'s interaction with you in relation to these websites.

Your use of CHI's websites are subject to the following terms:

  • The content of these websites is for your general information and use only and is subject to change without notice.
  • Neither we nor any third parties provide any warranty or guarantee as to the accuracy, timeliness, performance, completeness or suitability of the information and materials found or offered on these websites for any particular purpose. You acknowledge that such information and materials may contain inaccuracies or errors and we expressly exclude liability for any such inaccuracies or errors to the fullest extent permitted by law.
  • Your use of any information or materials on these websites is entirely at your own risk. CHI shall not be liable for any consequences. It shall be your own responsibility to ensure that any products, services or information available through these websites meet your specific requirements.
  • These websites contains materials which is owned by or licensed to CHI. This material includes, but is not limited to, the design, layout, look, appearance, content and graphics. Reproduction is prohibited other than in accordance with the copyright notice, which forms part of these terms and conditions.
  • Through these websites you are able to link to other websites and content which are not owned by CHI. We have no control over the nature, content and availability of those sites. The inclusion of any links does not necessarily imply a recommendation or endorsement of either their content or the views expressed within them.
  • All trade marks reproduced in these websites are the property of their respective owners.
  • Unauthorised use of these websites or the content therein may give rise to a claim for damages and/or be a criminal offence.
  • Every effort is made to keep these websites up and running smoothly. However, CHI takes no responsibility for, and will not be liable for, any website being temporarily unavailable due to technical issues.

Privacy Policy

Online Privacy

You take online privacy seriously, and so does CHI. It's our way of sustaining your trust in our company as well as in our products and services.

Non-Personal Information

In general, you can visit the CHI website without telling us who you are or revealing any personal information about yourself, however our web servers may collect and store information about your visit on an anonymous basis. This information may include the time and length of your visit, your interaction with our sites, and the site you visited just before coming to ours. We may also store your IP address, browser type, and country of origin. We use this information only to measure site activity and to develop ideas for improving our sites. Under no circumstance will this information be provided to any third party.

Personal Information

CHI may ask you to register and provide information that personally identifies you, such as name, e-mail address, mailing address or phone number ("Personal Information"). This will occur in certain circumstances, including for example, when you download trial software, sign up for newsletter services, download updates, purchase products or services, contribute content to our forums, access technical support, or join a limited-access service. We use your Personal Information for three primary purposes:

  • To enable you to find or gain access to information, products, services, or to post attributable content on our websites.
  • To help us personalize the content or navigational choices presented to you in order to make your future experiences on our web site as efficient as possible.
  • To allow us to inform you of product updates, new content, new products and services, as well as upcoming events that may be especially pertinent to you.

Under no circumstance will your Personal Information be provided to any third party.

What Information Do We Collect?

For registered users or purchasers of a product or service, the type of information we collect and maintain on our secure Personal Information server falls into three categories.

  • The first is general information about you such as name, billing address, e-mail address, company name, etc. We do not store credit card information as part of your Personal Information.
  • The second is information about which products or services you have purchased or registered for.
  • The third is historical information regarding your use of our products and services.

These three categories of information enable us to customize the presentation of our online content for you and is used for the sole purpose of improving your experience when using our products and services. Once again, under no circumstance will this information be provided to any third party.


Cookies are small pieces of information that are stored by your browser on your computer's hard drive. Our cookies do not contain any personally identifying information. They only contain a secure identifying code that we use to match you to your Personal Information whenever you return to our sites. Your Personal Information is never directly connected to nor stored on your computer, but is accessed when we identify your cookie to provide you with a more personalized experience when visiting our site.

CHI reserves the right to alter our privacy principles as business needs require. Any alterations to these principles will be posted here.

Contact us

For more information or for a quote on any of our products and services, please contact us.

Computational Hydraulics Int.
147 Wyndham Street North, #202
Guelph, Ontario, Canada
N1H 4E9

Email: info@chiwater.com
Tel: 519-767-0197
Toll Free: 888-9PCSWMM

CHI HQ - The Old Wellington Hotel Building

Regular business hours are Monday to Friday from 8 a.m. to 4:30 p.m. EST.

Current local time in Guelph: Saturday, March 25, 2017 5:34 AM.

To view a map of our location, click here.