A discussion of low head dam hydrology, and what features make a dam dangerous, and how to mitigate them.
A list of low-head dam related fatalities nationwide:
http://krcproject.groups.et.byu.net/browse.php
A list of dam-related fatalities in Iowa going back over 100 years. Iowa has done a remarkable job removing or modifying low head dams.
http://www.iowawhitewater.org/lhd/fatalities.html
The original video on dam safety: The Drowning Machine