That's a great deal of water.

In August 2005 we went to see the Imatra Rapids. They're harnessed for hydropower, but every now and then the gates are opened. It's an amazing show of power:

Pic: 22:15: The gates of the dam are still closed.
Pic: 22:20: Somebody turned on the lights. (and I used the flash on my camera).
Pic: 22:25: The water begins.
Pic: 22:26: ... moving on ...
Pic: 22:26: ... and on ...
Pic: 22:27: ... and on, completely covering the stones now.
Pic: 22:28: Still going strong. And I've turned off the flash on my camera. Should've done that much earlier.
Pic: 22:32: A nice view of the gates with the water at maximum level.
Pic: 22:34: the same view, but from the bridge.
Pic: What bridge, you ask? Here's a pic, taken about 5 minutes before that ^ pic.
Pic: 22:35: a view to the other side.
Pic: 22:36: still going strong.
Pic: 22:42: things are slowing down.
Pic: 22:42: the right-hand gate closed.
Pic: 22:43: the left-hand gate is almost closed.
Pic: 22:43: no more water.

It took surprisingly long for the water to drain away from the riverbed, after that last photo.