Dam it.

[ltfire]

What did they do with the water while they built the Hoover Dam? For that matter, same question for any dam. Diversion?

[enipla]

From the specials I’ve seen on the Hoover/Glen Canyon dam. They diverted it through HUGE tunnels to either side of the dam.

Amazing stuff.

[Squink]

From the Hoover Dam Faqs:

The river was diverted around the dam site through four 50-foot diameter tunnels, two on each side of the river drilled through the canyon walls. The tunnel, with a total length of 15,946 feet, or about 3 miles, were excavated to 56 feet and lined with 3 feet (300,000 cubic yards) of concrete. The tunnels could carry over 200,000 cubic feet - more than 1.5 million gallons - of water per second!