Those Dammed Lakes - Hydro-Environmental Analysis: Freshwater Environments - page 313

FIGURE 10.38 The 1995 Folsom Dam radial gate failure. (From USBR, Best Practices and Risk
Methodology , Chapter 16, U.S. Department of the Interior, Bureau of Reclamation, 2009.)
FIGURE 10.39 The 2010 Delhi Dam failure in eastern Iowa. (Republished from KRCG.com. © 2010
SourceMedia Group, Cedar Rapids, IA. With permission.)
Of the 84,130 dams in the NID 2009 database hazard rating, 13,991 are listed as high-hazard
dams and an additional 12,662 as intermediate-hazard dams. A high-hazard dam is one where there
is a high probability of loss of human life if the dam fails. The failure of an intermediate-hazard
dam may result in loss of human life but will more likely result in signiicant property or environ-
mental destruction.