From 168BTHPM:
Doesn't the water have to be moving to need spotters? I have spent a lot of time in TX,, LA, MS and FL after hurricanes and never considered stepping on a dead body to be a hazard, it's the live ones that pose a threat. If someone is enough of a moron to get sucked into a 36" drain and not know it's there they are pushing the limits outlined by Darwin, especially if they are only 30' from a hyper active waterway and the drain is running wide open, 36" drains are not sneaky. The biggest threats I ran across in flooded areas were the snakes, alligators and looters.
To 168BTHPM:
I too have spent many a day in flood waters post hurricane, levee break, heavy rains and otherwise. Actually the water does not have to be moving when you are worried about flooding incidents and submerged obstacles (foot entrapments, drop offs, sunken debris, etc). Upstream spotters and downstream safeties are additional layers of safety if the water becomes dynamic. In the case I cited above, the water was relatively still and the drain was hidden by debris, and brush. The 2 rescue personnel were sucked into the drain when they were approaching the hidden submerged drain, as there was no vortex or other indicators of such. So I disagree with he Darwin, but to each his own. I however will agree with the vector controls about animals, domesticated, human or otherwise.
From Bluegrasspicker:
I have to disagree. I eat drink and breath whitewater. Boating the Big Sandy in northern WV is the most productive thing I've done all weekend, but at least I did it twice. I really meant to get those taxes in. By my perspective those guys were all very, very safe. Granted, with infinite time they should be as careful as they were, but if there were other concerns I'd say grab the guy on the roof (if he wants grabbed, of course) and move onto the next rescue.
I do appreciate your statement regarding sieves. The tell tale sign for me is current in without flow going out. Water goes in, none goes out. I pick that up as ripples or a pillow that looks smaller than it should be with the water going in. The video doesn't show any ripples so I wouldn't think there are sieves.
With that said, I have minimal experience with whitewater outside of natural flows. The storm drain dynamic might be a source of nightmares for me tonight.
To Bluegrasspicker (Bob),
I see your point with the natural flows. In the case I cited it was very similar to the short video that was posted above. Engineered waterways are meant to move water as efficiently as possible, and when flooded, it is difficult to see hidden hazards that are man made and engineered into the waterway. In natural white water the flow tells you where "most" dangers are present, smiling/ frowning holes, strainers, etc. In still water it can be very difficult to discern where manholes have been uplifted, chain link fences are present, shopping carts are sunken, pipes/ drains, and undermining has occurred, etc.
As I said earlier, I am happy to have these discussions via email or pm or by phone. I am always willing to learn more in the opportunity to keep others safe. To the mods, I am sorry for my long postings and apologize for my hijacking of this thread. Now, back to the regularly scheduled programming........