Floods & Flood Frequency Schultz House Johnstown, Pennsylvania 1889 Modern Marvels: The Buffalo Creek Disaster • http://www.youtube.com/watch?v=qMcKyLcQWvQ Buffalo Creek Flood: An Act of Man Appalshop Video Clips The Buffalo Creek Flood: An Act of Man chronicles the 1972 disaster which killed 125 people and left 4,000 homeless when a coal-waste dam collapsed at the head of a hollow in Logan County, WV. • Buffalo Creek Flood Part 2 • http://www.youtube.com/watch?v=sn9Fd3TieCs&feature=related • Buffalo Creek Flood Part 3 • http://www.youtube.com/watch?v=fgdFcLvQfe4&feature=related 1 • Flood Banks & on to Surface next to Channel) • = Flow Rises Above Stream Stage Flood Terms Arbitrary • Discharge • = Height of Water Recurrence Interval Floodplain – Datum) Average Given Size or larger= Volume/Time (cfs, cms) (Nearly Level Time Between Events of a (Above • RecurrenceFlood Interval: Frequency Like Rolling Dice • 100 year flood - • 1 percent flood - Better BAD TERM FrequencyFlood Extrapolation Interpolation ? 200 2 Study this on Pages 248-249, Box 10.2, 10th Edition Big Floods Change Flood Recurrence Calcualtions. Many WV Flood Insurance Risk Maps (FIRM) Predate Big Floods of Last 20 years Harpers Ferry, 1870, ~ 60 Deaths One of Many Communities with Long History of Floods Harpers Ferry, 1889 3 Harpers Ferry,1936 Harpers Ferry, Sept. 1996 The Floodplain is Part of the River We should not be surprised when, sooner or later, the river exerts authority over its entire domain! 4 How much did water rise in <10 hours? Guyandotte River Hydrograph Thayer, WV, NPS Photo Mullens, July 2001, J. Carr Photo 5 Itmann Bridge, July 2001 Mullens High Water Marks Mullens Furniture Store, J. Carr Photo 6 The November 1985 Flood: RaincoatsWhy onStudents Kite’s FieldShould Trips Bring Lewis Creek, 3 Nov 1985 November 2, 1985 Cheat, Potomac, Shenandoah & November 1985 Flood in Greenbrier River Basins t ea Ch Greenbrier Potomac Shenandoah 7 Ice’s Ferry Bridge 11 a.m. 5 Nov 1985 Pt. Marion, 5 Nov 1985 (Before the Police Tried to Bust the Geomorphologists) Pt. Marion, PA, 5 November 1985 8 Corps of Engineers Burning Flood Debris from Lake Lynn (= Cheat Lake). White Rectangles: Refridgerators, etc. Normal Flow on Cheat River, Jenkinsburg 5 Nov 1985: 175,000 ft3/s 9 Pyramid Rock Moved, Cheat Canyon Welcome to Albright Albright, WV, Aerial View Scour 10 Albright, WV, 7 Nov 1985 Albright Church Trailer Frame on Albright Power Plant Bridge 11 Cheat Narrows: Squirrel Rock Did Not Move Mattress in Tree Near Squirrel Rock Asphalt Slabs, St. George 12 Household Debris in St. George Ditch House Damage, Parsons Welcome to My Living Room, Parsons 13 CondemnedCondemned House, ParsonsHouse Nursery Bottom, Parsons Scour on Black Fork of Cheat 14 Ramp and Gravel Splay, Black Fork Scour of Floodplain Near Petersburg, WV Photo by Ron Estep, NRCS Double Helix: South Branch RR Photo by Doug Lofon 15 Large Scour Near Petersburg Photo by Bill Gillespie, Nov. 1985 Bent Steel I-Beam, Petersburg Photo by Doug Lofon Riverton EMS Building 16 Germany Valley, 1985 Flood Damage North Fork South Branch Potomac River, Hopeville: Before North Fork South Branch Potomac River, Hopeville Anticline 17 North Fork South Branch Potomac River, Hopeville: After North Fork South Branch Potomac River, Hopeville: After North Fork South Branch Potomac River, Hopeville: After 18 North Fork South Branch Potomac River, Hopeville Rt. 28/55, Near Champe Rocks: Before Rt. 28/55, Near Champe Rocks: After 19 Rt. 28/55, Near Champe Rocks: After Rt. 28/55, Near Champe Rocks: Before Paleo-Channels Lewis Creek, 10 Nov 1985 20 Macomber: Spring 1986 Next Flood Tragedy in the Making Tygart Valley River, Grafton, Bridge Destroyed 10 July 1888 Anybody know story behind this “bridge? The Floodplain is Part of the River We should not be surprised when, sooner or later, the river exerts authority over its entire domain! 21 Flood Problems are People Problems Ignorance of Rivers and Streams Poor (Selective?) Memory of Historic Floods Arrogance of Our Ability to Overcome Nature Greed to Exploit Floodplain Property Lack of Zoning and Planning Sooner or later, the river exerts authority over its entire domain! Ch. 11 After Test 2 Ground Water or Ground-water or Groundwater Hydrology: Study of Water (Implies Surface Water) Hydrogeology = Ground-Water Hydrology 22.