John,

Due to the amount of gravel in the “soil” at The Proving Grounds rarely can a pond be created that holds water. I’ve created two that have worked well!  One I placed a polypropylene liner in the bottom – on top a two layers of used carpet. The carpet was simply to keep the liner from being punctured by rocks.  This pond has held water for five years!  

I created a second by spreading bentonite clay two to three inches deep across the pond (pond has a 20′ diameter).  This pond has held water also!  It has went dry during a drought (I built it too shallow) but held water once it rained!

The polypropylene cost less per unit area, but that pond produces more algae (pond scum) than the other pond. I’m not sure if this is due to the polypropylene, location, etc.

Enjoy creation,

grant

November 9, 2015