Kelly Barnes Dam Failure, Toccoa, GA, November 6, 1977. 139 killed
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PROFESSIONAL & TECHNICAL EXPERT SERVICES
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- Dam Safety
Distribution of Tennessee's 660 regulated dams.
Tennessee Dam Safety Facts
o Tennessee’s Safe Dams Program, which followed enactment of the Safe Dams Act of 1973, is administered by the Tennessee Department of Environment and Conservation (TDEC).
o Tennessee regulates non-federal “dams” defined as being 20 feet or more in height or having an impounding capacity of at least 30 acre-feet. However, dams less than 6 feet, regardless of impoundment volume or dams impounding less than 15 acre-feet, are not regulated for safety.
o Currently, Tennessee has approximately 1240 dams of which only about 660 are regulated for dam safety. The remaining 580 dams (47%) are exempted from state dam safety regulation, licensing, and inspection, regardless of height or impounding capacity, because they are
- Used for conservation, recreation or agriculture by only the owner and which are closed to the general public. These are called "farm ponds" and can be any size, condition or hazard category, such as having the potential to cause loss of life and/or property damage in event of failure.
Also exempted from state regulation are dams
- owned or operated by the Federal government, such as TVA, Corps of Engineers, DOE and USFWS (about 96 dams)
- or licensed by the Federal Energy Regulatory Commission (FERC) (3 dams).
o Tennessee’s Safe Dams Program, which followed enactment of the Safe Dams Act of 1973, is administered by the Tennessee Department of Environment and Conservation (TDEC).
o Tennessee regulates non-federal “dams” defined as being 20 feet or more in height or having an impounding capacity of at least 30 acre-feet. However, dams less than 6 feet, regardless of impoundment volume or dams impounding less than 15 acre-feet, are not regulated for safety.
o Currently, Tennessee has approximately 1240 dams of which only about 660 are regulated for dam safety. The remaining 580 dams (47%) are exempted from state dam safety regulation, licensing, and inspection, regardless of height or impounding capacity, because they are
- Used for conservation, recreation or agriculture by only the owner and which are closed to the general public. These are called "farm ponds" and can be any size, condition or hazard category, such as having the potential to cause loss of life and/or property damage in event of failure.
Also exempted from state regulation are dams
- owned or operated by the Federal government, such as TVA, Corps of Engineers, DOE and USFWS (about 96 dams)
- or licensed by the Federal Energy Regulatory Commission (FERC) (3 dams).
Distribution of 580 exempted (unregulated) "Farm Ponds" by Tennessee County (June 2015)
o Of the 580 exempt unregulated dams, about 68 dams (11%) are classified as “High Hazard,” meaning they have the potential to cause loss of life.
o Of the 660 regulated dams, about 150 (23%) are classified as “High Hazard."
o Over 80% of Tennessee’s non-federal dam failures since 1973 have been exempted unregulated dams.
o As of May 2015, 12 regulated dams remain deficient because they do not meet Tennessee's dam safety standards. It is unknown how many unregulated private dams are deficient.
o About 40% of Tennessee’s dams are at least 50 years old. By 2020, 55% will reach at least 50 years.
o Of the 660 regulated dams, about 150 (23%) are classified as “High Hazard."
o Over 80% of Tennessee’s non-federal dam failures since 1973 have been exempted unregulated dams.
o As of May 2015, 12 regulated dams remain deficient because they do not meet Tennessee's dam safety standards. It is unknown how many unregulated private dams are deficient.
o About 40% of Tennessee’s dams are at least 50 years old. By 2020, 55% will reach at least 50 years.
Distribution of the Corps of Engineers National Inventory of Dams (NID) in the U.S.
National Dam Safety Facts
o The 2016 Corps of Engineers National Dam Inventory (NID) lists 90,580 federal and non-federal dams in the U.S. See NID-dam definition sketch below.
o All states, except Alabama, regulate the safety of about 70% of the listed 90,580 NID dams. Almost 4 % of these dams are owned by federal agencies. The FERC regulates over 3000 dams in its dam safety program.
o All federal bureaus and agencies, who own, construct, operate/maintain or regulate dams are required to follow comprehensive Federal Guidelines for Dam Safety.
o The 2016 Corps of Engineers National Dam Inventory (NID) lists 90,580 federal and non-federal dams in the U.S. See NID-dam definition sketch below.
o All states, except Alabama, regulate the safety of about 70% of the listed 90,580 NID dams. Almost 4 % of these dams are owned by federal agencies. The FERC regulates over 3000 dams in its dam safety program.
o All federal bureaus and agencies, who own, construct, operate/maintain or regulate dams are required to follow comprehensive Federal Guidelines for Dam Safety.
NID-dam definition based on height, impdmt. capacity & other.
o The average age of the nation’s dams is 56 years. Many were built with older technology and are not expected to withstand current predictions of floods and earthquakes.
o The American Society of Civil Engineers (ASCE), in its 2016 Report Card for America’s Infrastructure, rated U. S. dams as "poor" (D).
o About 4,000 dams have been determined to be “deficient” and not capable of meeting current structural or hydraulic standards. Over half, or 2170 of the state regulated deficient dams, are classified High Hazard and have the potential to cause loss of life in event of failure.
o ASCE's 2017 Infrastructure Report Card reports that over 15,500 dams in the U. S. are classified as High Hazard.
o It is estimated in the 2017 ASCE Infrastructure Report Card that an investment of nearly $45 billion is required to repair aging, high hazard potential dams. The Association of State Dam Safety Officials (ASDSO) estimated in December 2012 that the total cost to rehabilitate all the nation’s non-federal dams to almost $54 billion.
o American Rivers reports that 1384 dams have been removed in the U.S. from 1912 through 2016. 72 were removed in 2016.
DAM SAFETY LINKS