This is a plan revision with a color overlay. The orignial plan was for a larger swimming pool which ran into budget constraints. The stream drops 27" over 22 feet which allows for cascading water before entering the pond basin where it gets pumped back via the skimmer box (symbol S/GFC on plan) up to the mouth of the stream (upper right hand corner.) [USDA Hardiness Zone 7b, Chattanooga, TN.]