Estimate how much water the barrier contains behind it in the lake.
If the barrier faulted, what do you think would happen? Consider; how much water would escape, and what kind of power is the escaping water equivalent to?
To estimate the volume of Garabaldi lake I multiplied the average lake depth by the lake area:
119 m x 9940000
= 1 182 860 000 m3 or approximately 1000 000 000 000 L
( If 1 cm3 = 1 mL and 1000 mL = 1 Land 1 m = 1 cm then 1 m3 = 100 L )
https://en.wikipedia.org/wiki/Garibaldi_Lake
If the barrier faulted I believe that most of the water of Garibaldi Lake would flood into Squamish. However, because the lake is 119 m deep I think that some of the water would stay in the lake, but most would flow out of it. The escaping water’s power would be:
If a cubic meter of water at 4 degrees Celsius is equal to 1 ton or 1000 kilograms then:
1 182 860 000 m3 = 1 182 860 000 tons
“The potential energy at 1,400 metres elevation, of 1 trillion litres of water, is 200 times the energy released by the bomb on Hiroshima”. Said Dr. Quane, a researcher of Garibaldi lake.
http://www.squamishchief.com/news/garibaldi-lake-a-ticking-time-bomb-1.1753732