Here is an Open field rain barrel system I made. This consists of 4 55 gal drums. One of the barrels if cut lengthwise. The center barrel has a 6 inch dia hole cut into it. There is PVC piping connecting the three barrels near the bottom. The caps for each barrel are on but are not closed tight, to allow air out as they fill. The center barrel has a valve which I had connected a garden hose. I put a screen over the cut out on top to keep the bugs out. The whole system is place inside fencing. I used conduit through the top barrels secured to the fence posts. As the center barrel fills it will automatically fill the other two barrel because of the PVC pipes.
Step 1: Pavers or Patio Blocks.
Place pavers or patio blocks big enough to place your three barrels.
Step 2: Fence Posts and Fencing
Place post in post holes, cemented if this will be permanent. Place post at the ends of the 3 barrels and between the 1 and 2. Add fencing as shown.
Step 3: Place Barrels.
Drill holes into the bottom edge from PVC pipes, Use threaded PVC pipe fittings.
Place the barrels in the fence, with the center barrel having a 6 inch dia opening cut into it. Cover the opening with a kitchen colander or window screen.
Step 4: Add Half Barrels.
Place half barrels on top as shown. Drill holes in the half barrels, and the posts, so a piece of conduit or threaded rod can be put through it to secure the barrels.
Step 5: PVC Pipes
Add 3/4 inch PVC pipe to the bottom of each barrel. Use a four way coupling in the center so a faucet can be added.
Step 6: Finish Project.
Enjoy your rain collection system.