1. Watershed Modeling using HEC-HMS and EPA-SWMM ©T. G. Cleveland, Ph.D., P.E. 10 July 2012 Lesson 1

2. Introduction Purpose Organization Resources – Lesson 1; Getting Started

3. Purpose Train engineers and scientists in the use of two professional tools (HEC-HMS and EPA- SWMM) for integrated hydrology and hydraulic modeling. Integrated the two tools can substantially simulate watershed behavior without resort to higher dimensional models, and that integration is focus of the course.

4. Purpose Course is a software-centric training course and assumes the participants have prior experience in hydrology and hydraulics Course further assumes that participants are computer literate and can comfortably function with concepts of files, paths, etc. “By-hand” computations in this course means using a spreadsheet.

5. Organization The course is organized into “lessons” Each lesson typically contains: – Narrative (in the notebook) – Presentation (a powerpoint) – Exercise (“Hands-On” or follow example) – Video (some lesson components have movies) – Readings (I will try to keep readings grouped with lessons, however many will apply across lessons)

6. Organization The course is organized into “lessons” Each lesson typically contains: – Narrative (in the notebook) – Presentation (a powerpoint) – Exercise (“Hands-On” or follow example) – Video (some lesson components have movies)

7. Resources The course will require you to have a laptop computer running the Windows operating system. You will need to download and install: – HEC-HMS – EPA-SWMM – Apple QuickTime viewer – ENGAUGE (optional, but really useful)

8. Resources Course materials are located in a server, the URL is presented in-class A subset will be distributed on a flash drive (you keep the drive)

9. Topics HEC-HMS and SWMM runoff models – the similarities and the big differences. Preparing geographic, hydraulic, and hydrologic data – the dirty work before modeling. – Use of Acrobat, Excel, and other common tools to prepare the time series for straightforward import into the programs.

10. Topics HEC-HMS models – Runoff, storage, unit hydrographs – Routing, design storms, complex catchment Troubleshooting HEC-HMS – DSSVue for irregular time data entry

11. Topics SWMM models of surface runoff and storage. – Relationship of hydraulic response and parametric unit hydrographs. Troubleshooting SWMM. Complex catchment hydraulic modeling. Integrating the two models for cases where SWMM hydrology is inadequate and/or HEC- HMS hydraulics are inadequate.

12. Philosophy The course is built on a training-type model rather than a knowledge-type model Learn by doing – Learning how to drive computer programs – Suggest which vehicle to choose for which terrain, but emphasis will be on how to move from conceptualization to simulation Won’t get much “formal” theory – acquire as necessary

13. Getting Started HEC-HMS is a hydrology program – Has some simplified hydraulics. – Flow is uni-directional. – Model is “link-node” relationship. EPA-SWMM is a hydraulics program – Has simplified hydrology. – Flow can be bi-directional. – Model is “link-node” relationship.

14. HEC-HMS Framework that integrates various hydrologic process models to produce estimates of discharge time series at locations of interest in a watershed. – Comprised of many sub-process models, some are always present, even if they are “null”, some may be absent.

15. EPA-SWMM Framework that links hydraulic component (pipes, reservoirs, pumps, etc.) models. These components are generally well documented physics models. – Simplified hydrology process sub-model as part of the system. – SWMM has a constituent fate and transport model. The hydrologic process sub-models are quite limited as compared to HEC-HMS.

16. Which to use? Using the driving analogy, depends on the terrain (and the driver). HEC has some nice built-in precipitation models. SWMM is crude in this respect, so might use HEC as a rainfall generator for SWMM (Crossover SUV?)

17. Installing Software The remainder of this lesson is a workshop to accomplish the following tasks: – Verify HEC-HMS install – Verify DSSVue Install – Verify SWMM Install – Verify ENGAUGE Install – Verify AppleQuickTime install

18. Documenting Your Work The exercises are “homework” in the sense that I would like you to document success/failure on each. For Verify-Type exercises, produce a letter report with screen captures. Print the letter report and hand-in, I will simply keep it in a file as record of completion. Later exercises will be more extensive, but short reports will be the sufficient documentation.