Check out what these guys did at Ladybower Reservoir :
http://www.flickr.com/photos/natwilson/ ... 249910699/
Here's a vid of the plug holes flowing:
http://fiveprime.org/hivemind/Tags/ladybower,reservoir
crazy, huh? Just watching that vid gives me the creeps.....
There's another reservoir like this in Calafornia called Lake Berryessa similar set-up