DES 602 - Discussion Questions
These questions are intended for discussion at the end of each appropriate training module as
time permits, and in module 23 as preparation for the final examination for the training course.
1. What is meant by the term “time of concentration”?
2. How is the intensity of rainfall computed?
3. How do the concepts of “probability” and “frequency” relate in the context of hydrology?
4. What factors influence the ponded width of water on a roadway?
5. What is meant by the term “contributing area”?
6. How does roadway cross slope influence ponded width?
7. How does roadway longitudinal slope influence ponded width?
8. Describe the meaning of each term in the Rational Equation Q=Cd*Cr*I*A
9. How do improved flow paths influence time of concentration?
10. How do improved flow paths influence computed intensity?
11. How does urbanization influence runoff?
12. What geometric factor connects ponded depth in the gutter to ponded width in the roadway?
13. What is an IDF curve?
14. What restrictions exist on the use of the Rational Equation?
15. What factors influence inlet spacing?
16. What is the “n” in Manning’s equation?
17. What is the meant by the slope term in Manning’s equation?
18. What factors influence inlet type (sag or inlet-on-grade)?
19. Name 3 differences between inlets on grade and sag inlets.
20. Which inlets are most commonly used on TxDOT projects with curb and gutter?
21. How does longitudinal grade affect inlet performance?
22. How does longitudinal grade affect inlet length?
23. Why would you want to design for carryover?
24. What conduit shape is most efficient for storm sewers?
25. At what d/D ratio (depth/diameter) does a circular pipe flowing partially full reach peak
discharge?
26. What are the lines called that join inlets to the downstream nodes in a system?
27. What are the lines called that carry accumulated flow in a system?
28. What two things (at a minimum) do storm sewers transport?
29. When would you need a hydrograph for storm sewer design?
30. What does a pump performance curve show you?
31. What factors should you consider in the selection of an outfall location?
32. Why might you consider constructing an inverted siphon?
33. What standard sheets does a designer need to have on hand when designing a storm sewer?
34. How should energy and velocity be managed as water proceeds downstream in a storm sewer?
35. Where should the trunk line of a storm sewer system normally be located?
36. What factors may influence the location of a storm sewer trunk line?
37. In which direction should conduits be constructed?
38. At what maximum angle should conduits join with a junction box?
39. What is the purpose of the angle restriction on conduits joining with boxes?
40. What hydraulic feature should match or drop when crossing a junction?
41. What physical feature should match or drop when crossing a junction?
42. What is needed before you can design and construct a storm sewer off of TxDOT ROW?
43. What environmental concerns might there be for the construction of a storm sewer?
44. What safety concerns might there be for the construction of a storm sewer?