Austin Dam, Texas

from Wikipedia, the free encyclopedia

Map: USA
marker
Austin Dam, Texas​
Magnify-clip.png
United States

The Austin Dam (also Austin Dam , McDonald Dam or Granite Dam ) was a dam on Colorado in Travis County in Texas , USA. It broke on April 7, 1900 during a flood. At least 8 people drowned.

The dam

The dam of the Austin Dam was a gravity dam from granite -masonry and 1890 bis 1892 / 1893 next to the old city of Austin has been the capital of Texas built. It was 60 feet (about 20 m) high and 1200 feet (about 332 m) long. It was 16 feet (4.8 m) wide at the top and 50 feet (15 m) wide at the bottom. The inside of the masonry consisted of limestone with a cladding of large granite blocks on all sides. The wall had been built so that it could be overflown over its entire width up to 16 feet (4.8 m) high; so high were the abutments on the sides. The foot of the wall was therefore strongly rounded.

The dam had a hydroelectric power station that was used to generate electricity . She also supplied Austin with water. The reservoir was called Lake McDonald and was the first major reservoir in Texas.

Half of the reservoir was silted up by sediment deposits. The dam wall was more heavily stressed by the additional earth pressure than by the water pressure alone, which indirectly led to the rupture later.

storm

Before the disaster, there was a two-day long storm with heavy rainfall in the Lubbock and Amarillo plateaus . The Colorado , Brazos, and Guadalupe Rivers swelled. The towns of Austin and Bastrop were surprised by the floods. The Colorado rose to 60 feet (20 m) and became a mile (1.6 km) wide. Austin's pride and joy, the 181-foot (54 m) long three-deck steamship "Ben Hur", was also destroyed in the flood.

catastrophe

In Austin, the rain began on April 6th at 4:30 am and lasted 24 hours. It had stopped on the morning of April 7th, and residents watched the water flow 11 feet (3.3 m) above the top of the wall. At 11:20 a.m., an explosive sound was heard and felt, and two large pieces of the dam were moved 60 feet (18 m) downstream. The breach can be seen in photos and could be 100 or 200 m wide. The flood hit the power station and flooded the lower floors, where five workers and three boys drowned. Houses and farms further down the river were flooded. Austin was without electricity for a long time, without light, and five weeks without water. The electric tram took months to return to service. One report puts the death toll as five plus three, others as seven to ten or even dozen. The first number refers to the dead in the power station directly at the dam, the higher number to the victims further below. It may also include general flood victims who cannot be traced back to the dam breach.

root cause

The cause of the break was the sliding of the wall as a result of excessive horizontal forces. The flowing water on the air side washed out and hollowed out the ground until the friction of the weight of the wall on the ground was no longer sufficient to hold the wall in place.

Aftermath

The dam was to be rebuilt in 1912 . However, the work was not finished. After the work was stopped in 1915 , the construction site was destroyed again by another flood. 1938 / 1939 a new dam was built on the site, which today Tom Miller Dam 's and Lake Austin forms. The new wall is 1,590 feet (477 m) long. Its coordinates are: 30 ° 18 'North, 97 ° 47' West. The once wild Colorado is now tamed by five other dams.

The 7. April 1900 remains Austin remembered as "The Day the Dam Broke" (the day on which the dam broke).

See also

literature

  • The Great Dam Across the Colorado River, at Austin, Texas. Scientific American, Vol. LXVII. - No. September 13, 24, 1892
  • Donald C. Jackson: Great American Bridges and Dams, John Wiley & Sons, New York (USA), ISBN 0-471-14385-5 , 1984; P. 330.

Web links