getut,
In 1999 we had another bad drought year here in Texas, such as we're having here now. That large tank was the only place my cattle had to water, and usually the shotgun fire will run the cattle away from the tank itself. Additionally, the trees on and around the tank dam provide shade cover for the cattle too on very hot days. I guess I'd have to answer you by saying that no, I wouldn't have allowed them to hunt had they asked in advance. Besides, 100 yds is too close to my house for people I don't even know to be shooting at birds flying this direction, and that direction.
Had they asked in advance to hunt at the opposite end of my property, I'd probably have said OK, but they never gave me that chance.