Lawn Lake Dam Failure ... Summary
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The Lawn Lake Dam failed. “At approximately 5:30 a.m. Mountain Daylight Time,
July 15, 1982, Lawn Lake dam, a 26-foot high earthen dam located at 11,000 ft.
in Rocky Mountain National Park, Colorado, failed. Full breach development was
estimated to have taken 10 minutes. The dam released 674 acre-feet of water at
an estimated peak discharge of 18,000 cubic feet per second down the Roaring
River valley [note: a class 5 rapids run, which is considered very dangerous, is
rated at 5,000 cfs.]. In the Roaring River, the flood wave was described as a
wall 25 to 30 ft. high. Three people were killed, and damages totaled $31
million. The Colorado State Engineer determined that the probable cause of
failure was deterioration of lead caulking used for the connection between the
outlet pipe and the gate valve, The resulting leak eroded the earth fill, and
progressive piping led to failure of the embankment”[i]
It is important to note that the day was clear and sunny. A classic Colorado
summer morning.
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| Original Lawn Lake. The dam is at the far (southeast) end.
Click for a bigger image. |
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Hikers at Lawn Lake just north of the dam. Hagues Peak of the Mummy Range
is in the background |
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The breach in the dam observed by a helicopter passenger with another copter at
the dam. |
Twelve miles east of, and approximately 3,500 feet below Lawn Lake, sat the
resort community of Estes Park, Colorado where, at 8:30 a.m., the floodwaters
from Lawn Lake came through the downtown area at the rate of 8,520 cubic feet
per second.
This map shows the route the water took from the breach in the Lawn Lake Dam all
the way to Lake Estes and Olympus Dam. Click image to enlarge.
Lawn Lake Dam Failure Summary Page 2
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