Next, I dug a trench around the perimeter of the patio and filled it with lots of rebar and concrete. On this footing of concrete, I built a wall of limestone 3 feet high. In this wall I put some limestone fossils which I found around our property. All of the limestone was free for the asking from the garbage piles leftover from houses being build! I also got permission to get scrap rock that I used to fill-in the patio. In addition to the scrap rock, I plumbed up four 55 gallon barrels to gather rain water from the patio. You can see them buried here. I put layers of decking material over the barrels to make sure that any weight would be distributed over the barrels.

Each barrel has 1) an inlet for water, 2) an up-riser pipe to let out air, and 3) an outlet pipe that siphons water from the bottom of the barrel.