Rivers with lowhead dams

[Joao]

Do you know any river with dangerous lowhead dams that was removed or addapted for rafting or kayaking?

We are working in a lowhead dam Portugal to make it suitable for kayaking and rafting.
We have some examples and technical issues that we got from University of Illinois, Hydrosystems Laboratory, but any more suggestions would be apreciated.

More information:
http://www.dnr.state.oh.us/water/dsafety/lowhead_dams/
http://www.dnr.state.oh.us/watercraft/facts/dams.htm
http://www.vtchl.uiuc.edu/our-work/publications/hes/HES-050.pdf

[mario.julia4]

Recreation on rivers and streams is a safe, wholesome outdoor activity. However, low-head dams can be a threat to an unwary boater, swimmer or wader. Of all the things you may encounter on a river or stream, the low-head dam is one of the most dangerous. In fact, if an engineer designed an efficient, unattended, self-operated drowning machine, it would be hard to come up with anything more effective than a low-head dam under certain flow conditions.

There about 250 dams in the Commonwealth that meet the statutory definition of run-of-the-river dams. These dams are supposed to be marked under the law. However, as many as 2,000 Pennsylvania dams can show the dangerous hydraulic characteristics of low-head dams under certain flows. What's more, a dam that may look safe can suddenly become very dangerous if flows change suddenly, such as during periods of high water or after storms. The dam can become a monstrous death trap when river levels are up. If river travel is something you plan for this year's recreation, whether canoeing, kayaking, swimming or cruising, be familiar with the river's dangers.

[Joao]

At 16th January we had the first drowning accident during rafting trip, caused by the low-head-dam. 8+guide got caught at the boil, 2 didn't escape and got out after drowned. 1 was lucky to be reanimated, the other went down the strong stream and recovered without life.
In spite of big efforts to change the dam, constructions and studies held during 3 years, it was not enough to prevent the hydraulic effect with all levels of water. Engineers said that they wouldn't adapt the construction for high levels of water because it would affect the stability of the dam it self (crap...). What they didn't expect was that in such short time after so many years comercial rafting being done there, the accident happened.

Is there any real study done with a real transformation of a low-head-dam?