Dam Safety 35 years later

Dam failure at Toccoa Creek (Note high water level on the house)

Imagine waking up and hearing news that during the night that a small college was practically gone due to a wall of water. A flash flood of epic proportions. A nightmare with no warning.

35 years ago in Northern Georgia, this actually happened. Just after midnight an unmaintained dam collapsed during heavy rains releasing 176 million gallons of water just above Toccoa Falls College campus. Thirty-nine people lost their lives. Sadly, twenty of those deaths were children.

An innocent mountain creek flowed through the heart of campus. Suddenly water in the creek turned red with Georgia clay, and guards at the college reported a wave of water five feet high. The dam had given away upstream. Water did what it does best – flowed downhill.

Eldon Elsberry, a maintenance worker for the college, was outside near the creek when he saw this wall of water.

The agony was awful. I knew a man’s wife and children were floating away….there were many screams, mostly from children. I stood on the bank and watched people die, but I couldn’t do a thing.” –Eldon Elsberry (Quote from the book Dam Break in Georgia by Neill Foster)

Several hours would pass before the sun would reveal the devastation and ultimately the hope of a brand new day. (I wrote about this in more detail here).

The following is a history of US dam failures with fatalities greater than 25 people (Compiled from a paper by Wayne Graham  titled Major U.S. Dam Failures: Their Cause, Resultant Losses, and Impact on Dam Safety Programs and Engineering Practice in 2009)

[table]
Dam,Failed,Age of Dam,Cause of Failure,Deaths
Mill River Dam MA,1874,9,Seepage and embankment sliding,138
South Fork Dam PA,1889,36,Overtopping from flood,2209
Walnut Grove Dam AZ,1890,2,Overtopping from flood,70-100
Austin Dam PA,1911,2,Weakness in Foundation,78
Lower Otay Dam CA,1916,19,Flood Overtopping,30
St. Francis Dam CA,1928,2,Dam Sliding,420
Buffalo Creek Coal WV,1972,0,Dam face slump,125
Canyon Lake Dam SD, 1972,39,Overtopping from flood,N/A
Laurel Run Dam PA,1977,63,Overtopping from flood,40
Kelly Barnes Dam GA,1977,78,Saturated embankment leading to slope failure,39
[/table]

 

As shown on table above, the 1970’s experienced a large number of dam failures compared to other decades. Within two weeks of the Georgia dam failure the Army Corps of Engineers personnel visited 95 dams in 49 states. Soon the Federal government appropriated 100 million as part of a National Dam Inspection Act.

Time has changed. Improved spillway design safety factors and better emergency planning have all helped to save lives. According to the ASDSO,  every state but Alabama has dam safety regulatory programs. State governments have regulatory responsibility for 80% of the approximately 84,000 dams.

With a growing population often near dams, the topic of dam safety is not sexy but it’s a continued need. Here are some recent dam safety resources of interest:

  • A new information flyer from the Association of State Dam Safety Officials (ASDSO) assists dam owners in understanding the importance of emergency action planning. The flyer was completed in February 2012. See Flyer.
  • INSPECTION AND ASSESSMENT OF DAMS SEMINAR November 13-15, 2012 at the Marriott Atlanta Gwinett Place, Duluth, Georgia. Register here.
  • DHS recently released two documents that describe some of the consequence estimation approaches used in North America, discussing their advantages and limitations. Estimating the Loss of Life for Dam Failure Scenarios and Estimating Economic Consequences for Dams.
  • EMERGENCY ACTION PLANNING FOR DAM SAFETY WORKSHOP, February 27-28, 2013 at the Marriott Downtown Hotel in Kansas City, Kansas. Register Here.