I built two small water holding holes a year ago just off a dip in a woods road that are the size of a pickup truck bed. They are in the shade on a ridge and only a took a little time for a dozer that was there logging so it was free. They hold water at all times although we haven't been in a drought yet. I dreamed of a 1 acre pond but found my soils weren't good enough for that. Ridges have surprisingly good water holding soils. Some people say deer don't need water but others say it helps, I see deer and turkey tracks in the mud but don't know if it is a significant improvement.