The pull on the water might actually be pretty insignificant. Much will depend on the amount of water going into the reservoir. If you know that the pull is not worth worrying about, it's neither brave, nor stupid. If you don't know whether the pull is significant, it's just plain old stupidity. Bravery requires someone to know the danger and still do something in spite of it. Being blissfully unaware of a danger that might go along with an act means that there's no bravery involved.