My mom runs a rescue and we have come across a common problem in the 12 years that this rescue has been going.

Male dogs, neutered or not, pee directly into their water buckets. And its not because the water bucket just happens to be in the area where they pee. They run over to them, and pee into them. They will also pee into the small swimming pools we have out for the dogs during the summer. I do know that male dogs have a tendency to mark their territory, but this is kind of ridiculous. We are constantly rinsing out and scrubbing water buckets because of this. Our solution, all water buckets are tied up very high so that no boy dogs can pee in these buckets.

Does anyone know anything about this behavior?

I'm a cat person, so don't know much about dog behavior. I'm sure a dog person will be along in a few hours to address your question.

Shreve Stockton adopted a male orphan coyote two years ago in Wyoming (dailycoyote.net) and noticed he likes to pee into still or running water. She trained him to pee in the empty not-running shower, right at the drain, at the times when the winter weather was too blizzardy to let him out.

I'm wondering if all (male?) canine-type animals like to pee into still or moving water. I Googled a bit, but didn't find an answer. I'll alert a dog expert to read your question.

Unfortunately I haven't heard of a dog doing this...
I do have a few theories though, perhaps it is the less dominant dogs that are urinating in the water to actually mask their scent so that it is only the dominant dog in the pack who's scent is being marked on actual objects like trees and grass.

Dogs always have a leader, the leader is their owner in most cases but with a bunch of rescues they would more than likely work out a hierarchy amongst themselves.

Like I said, just a theory ;)

I have seen these boys line up to pee in the same bucket of water. I have also seen two dogs stand on either side of the bucket and pee into it. And this process could go on for minutes at a time.

You could perhaps try providing a flatter pan of water in the middle of their pens to urinate in...
I am unsure of the setup your mom has but the shelters here are concreted pens, it shouldn't be too hard to pressure spray around the pan to get rid of any 'spills'

You could try licky bottles for them, not just the kind you get for rabbits, you can get extra large ones for dogs.

http://www.mrfooshihtzu.com/BellaMrFooWaterBottle.JPG

The dogs run free on our acre lot. Only the grumpy ones are put into kennels and our escape artists are tied out on a chain. We have water buckets in almost every corner of the yard. These monster would grab those licky bottles and chew them into chards. The buckets are all chewed up on the lips and some can't even hold a full amount of water because of the cracks.

I was just curious if anyone has ever seen or heard of this bazaar behavior in male dogs