This teaching PPT was used to introduce the physics behind dams and the consequences of the Johnstown, PA flood.

6. Flash Floods and Dams Preview for Johnstown

12. Embankment Dam: Forces Water pushes against the embankment dam, but the heavy weight of the dam pushes down into the ground and prevents the structure from falling over. “ Building Big, Dam Basics”. PBS.org. 4/1/08 <http://www.pbs.org/wgbh/buildingbig/index.html>

13. Embankment Dam New Waddell Dam Maricopa County, Arizona Photo, U.S. Bureau of Reclamation

19. Scenario: Dams don't last forever. Hot and cold weather makes them crack. Water erodes their foundations. They create environmental problems. Eventually, every dam must be repaired, removed, or replaced. You are a consulting dam engineer, and today, four dams need your attention. It is your job to advise the dam owners whether their dams must be repaired, taken down, or simply left alone. Listen to what the supporters and opponents of each dam have to say. Like all dam engineers, you must weigh the pros and cons before you make your final decisions. Good luck! “ Building Big, Dam Challenge”. PBS.org. 4/1/08 <http://www.pbs.org/wgbh/buildingbig/index.html>

23. Original Design Smoter-Frank, Walter. “The Cause of the Johnstown Flood: A new look at the Historic Johnstown Flood of 1889.” Civil Engineering . May 1988, 63-66. http:// smoter.com/flooddam/images/culvert.jpg

24. Reconstruction Smoter-Frank, Walter. “The Cause of the Johnstown Flood: A new look at the Historic Johnstown Flood of 1889.” Civil Engineering . May 1988, 63-66. http:// smoter.com/flooddam/images/culvert.jpg

25. South Fork Dam http://www.nps.gov/archive/jofl/image3.gif National Parks Service

26. http:// www.jaha.org/FloodMuseum/Dam.jpg

27. http://www.shadedrelief.com/birds_eye/more_images/townsend/johnstown3.jpg

29. South Fork Dam and club house. c1889 Courtesy Library of Congress

31. Looking west on Main Street. c1889 Courtesy Library of Congress

35. Cambria Company's store looking towards Kernville. c1889 Courtesy Library of Congress

36. General view of Johnstown looking towards Kernville. c1889 Courtesy Library of Congress

37. Close up of previous view. c1889 Courtesy Library of Congress

38. Club House Press looking south. c1889 Courtesy Library of Congress

39. Club House and Morrell Institute. c1889 Courtesy Library of Congress

40. View showing relief camps. Wood, Morrell & Co.'s store and office from Prospect Hill. c1889 Courtesy Library of Congress

41. Close up of relief camps from previous photo. c1889 Courtesy Library of Congress