Gary Rensi's pond in Monroe, Michigan, is a constantly evolving. He always wanted a pond and a waterfall in his yard, and once he began building them, he never really stopped. He began by gathering boulders and rocks to form a foundation for the pond, which took a few years. With the help of a tractor, he placed every boulder and rock himself. Total cost of his project: $5,000. Although Gary admits that his pond takes quite a bit of time to maintain, he continues to add more shrubbery, plants, and flowers each year.