Water falling freely, catch it if you can! Water is an increasingly valuable resource in our densely populated and warmer world. To reduce our demand on the aquifer, rainwater catchment systems can fulfill your outdoor water needs: water to fill a pool, a pond, or to irrigate a garden, and reduce the expense of municipal water or strain on the aquifer.
With containers, size matters. I started with 5 gl buckets along the drip edge of the house. This low tech system provides a handy back-up for post hurricane water needs. The next size up is the 55 gl barrel but I found these tedious and insufficient for my watering needs. Barrels are fine for a small gardens. If you want volume, IBC or international bulk containers are the way to go. IBC are big square plastic with a metal grill wrapped around it. They can hold 250 or 325 gallons and are immensely easier to plumb than the small round barrels.
Upscaling to barrels and IBC requires planning. Your containers should be central to where the water will be used, and mounted up on blocks and gutters siphon water from the roof towards your container. Gutters need to meet THREE criteria: (1) slope to drain towards your containers , (2) angle down and away from the roof to allow debris to wash off and (3) use gutter guards to prevent clogging.
Containers also need to block light to prevent algae growth within the barrels. Some remove the grill, and spray paint the barrels black. I wrapped mine in UV resistant tarp like a pretty gift package. It’s best if you can install your barrels in the shade to keep them cool and out of destructive UV. If you can, situate your barrels away from your house to protect your foundation in case of a leak. Your container will have to be mounted on solid blocks (think weight distribution) in order for it to drain into your sump. A sump is a bucket your water drains into for you to pump it to where it is needed.
Connecting the gutters to the containers is the next step. I prefer to adapt my downspout to a 4″ PVC pipe that drops down to a clean-out, then back up to the top of the IBC to a Y with overflow. Here is where it gets technical and there are a bevy of do-it-yourself resources listed at the bottom of this blog.
I drain my water into a sump, a 30 gl tub , and pump it out to by hose using a sump pump. The most common and heartbreaking mistake I still make to this day is opening the valve then walking away to do something else and forgetting I left the water on. The good news is, there is always more rain to refill the barrels and if I fix part of the hose to a fixed level above the tub, it will only drain to the height I secured part of the hose.
Like the proverbial $250 tomato, the start-up costs and ENERGY to install a rain catchment system had me questioning my sanity, yet I have saved hundreds of gallons from being pulled from the aquifer and billed to my water account. The payback was quick, a couple of years to recoup my costs and the satisfaction of doing my bit to reduce the draw from our aquifer.
Other Resources:
- IFAS Hillsborough County has a handy brochure you can download.
- SWFWMD has a website describing the process.
- Some of the best tutorials I have saved after watching hundreds of tutorials and installing my own system are produced by The Kombucha Company, see their multistep approach.
- Take care of Texas Resources has a good brochure on Harvesting Rainwater
- Useful terms: overflow, diverter, and sediment traps.
OSFR President Joanne Tremblay
joanne.tremblay@oursantaferiver.org
“Giving Our River A Voice”
