I like ducktapeguy's thinking.

I often drive over flooded roads (still-water usually caused by beavers, up to about 30" deep) and I always walk through the new ones first to check for hidden hazards. This will reduce the risk of crossing flooded areas and prevent you from taking a serious heckling from your co-workers for getting stuck and needing a tow out!

As already mentioned, stakes along the edge of the flooded road help gauge changes in water depth and also direct you to stay on the road-bed. Twice I have rescued people who have dropped off the road-bed into the same lake while launching a boat, it is not that the water is dangerous (no current and about 5 feet deep) but that it is a 16km walk out to the highway.

I caught a group of grown men one time throwing big rocks (about 1 foot in dia.) into a large deep murky puddle on a Hydro access road, to discourage other people from traveling into the public area where they were hunting/fishing. It was difficult not to laugh as they waded into the slop to remove the rocks, so an unknowing person driving through the flood did not injure themselves or there property.

Another nasty trick is to pour paint or stain into a stagnant puddle, every vehicle that drives through it after that gets an unwanted paint job.

You do not see things like this often but when you do it can really upset you, most people have much more respect in the woods.

Mike