History of Dams & Dam Failures

History of Dams

• Earlier Adventures of Dam Constructions

  • The oldest dam is called Jawa Dam and it found in the country Jordan

    • This dam was built in the 4^th millennium BCE and it was responsible for holding back the water of a small stream

  • There is evidence that another dam was built near Cairo, Egypt around 2700 BCE, it was called the Sadd el-Kafara. This dam was a gravity dam, meaning that it used its weight to resist the water load
    • This wall was made of rubble masonry walls on the outsides and filled with 100,000 tons of gravel and stone
    • A limestone cover was placed on the outside to resist erosion and wave action
    • The dam failed a few years later due to overflow. The dam was not water tight and water flowed through it quickly which allowed the water to erode it away
  • The next dam known dam was built in 2000 BC called the Nimrod's Dam in Mesopotamia
    • It was an earth dam; they are like gravity dams except it is made from soil
    • The dam was watertight, with a core wall and filled with an impervious center usually made of clays.
  • Due the large size and the amount of building materials that were required to build a dam, the arch dam was created to reduce the materials used
    • The first ever known arch dam was in the 1280 AD in the Mongol period called the Kebar

• How Dams were Constructed between 1850-1900

  • In the second half of the 19^th Century, there was a increase in population in California due to the gold rush
    • Since water was used for mining, the residence wanted to market on the water usage, and they built dams to help them
    • The dams were small, and their purpose was to direct the water to the mining areas. They were mainly constructed with earth and rocks
  • Soon after that, the technology improved, and it allowed for California to build a bigger concrete dam
    • The Lower Crystal Springs Dam provided a significant example of a concrete gravity dam that set a precedence for future dam design. It was built in the 1888 near the San Andreas Fault. This dam was able to withstand the 1906 San Francisco earthquake with little to no damage.
  • The constant Arch design also came about in the 19^th Century once again to reduce the material that needed to be used. It was possible due to new engineering and technology advancement
    • It used its shape to withstand the water pressures unlike the gravity dam that resistance it by its weight
    • However, even though new advances were discovered, the stresses that occur on the arch dam were not fully understood, so most of the arch dam’s resembled gravity dams with broad cross sections

Dam Failures

In the United states alone there has been over a hundred dam failures. Below are some examples that have occurred over the years. These dam failures are the ones that have contributed greatly to the legislation of dam construction.

• St. Francis Dam Collapse, 1928

  • The collapse of this dam was the second-greatest disaster in California history at that time.
  • It was estimated that 400 to 600 people died due to this collapse.
  • This collapse was inevitable since from day one there were leaks within the structure
  • The wall span 396 meters of concrete in the San Francisquito Canyon
  • It held 12 billion gallons of water; it was a year’s supply for the entire city about 80 km to the south
  • There were even inspectors who inspected it and vouched for its safety when it was leaking the morning of the collapse
  • This failure had encouraged the state of California to create safety legislation according to the construction of dam, something that was not present before this incident
    • However, some states still did not include legislation in relation to dam construction until the 1970’s

• 1970’s Dam Collapses

  In the 70’s alone, there were 5 dam collapses in the United States. It was not until the collapse of the Toccoa Falls, Georgia in 1977 did the President Jimmy Carter direct the US Army to inspect the nation’s non-federal high-hazard dams. This phase 1 program lasted form 1978-1981 and the finding of this program was responsible for establishing a dam safety programs that the most states would have to obeyed by. This program was called National Dam Safety Program.

All information about previous collapses in the United States along with dam regulation can be found at:

https://damfailures.org/