Capture free water from your roof - 1" of rain = 600 gallons from average roof
A 1,000 sq ft roof collects about 600 gallons from 1 inch of rain. Most places get 30-50 inches of rain per year. That's thousands of gallons of free water literally falling from the sky that you're sending straight to the storm drain.
| Item | Approx. Cost | Buy |
|---|---|---|
| 55 gallon food-grade barrel | $20 | Amazon |
| Spigot/valve | $8 | Lowe's Amazon |
| Overflow hose (garden hose) | $5 | Lowe's |
| Fine mesh screen | $3 | Lowe's |
| Downspout diverter kit | $4 | Lowe's |
Search Craigslist, Facebook Marketplace, or call local food processing companies. Pickle/olive barrels are common. Must be food-grade plastic (look for HDPE marking). Clean thoroughly.
Drill a hole 3-4 inches from the bottom. Install spigot with rubber washers inside and out. Use Teflon tape on threads. Position spigot on the side facing away from the house for easy hose access.
Drill another hole near the top (2-3 inches below rim). Install a bulkhead fitting or hose adapter. Attach garden hose to direct overflow away from your foundation. This is critical - barrels fill up fast.
Cut a hole in the top of the barrel to accept your downspout (usually 3-4" diameter). Cover this opening with fine mesh screen secured with zip ties or wire to keep out mosquitoes and debris.
Cut your existing downspout where you want water to enter barrel (usually 2-3 feet up). Install diverter kit that directs water into barrel. When barrel is full, water automatically flows down original downspout path.
Place barrel on cinder blocks or a platform (raises it for better water pressure). Must be level and stable - 55 gallons weighs 450+ lbs when full. Position near downspout and connect.
Run water from your hose into the inlet to test for leaks. Check that overflow works properly. Verify spigot doesn't leak. Fix any issues before the first rain.
Check local laws: Rain barrel collection is legal in most US states, but a few have restrictions (mainly western states with water rights issues). Most places encourage it now.
Not for drinking: Rainwater from roofs contains contaminants from shingles, bird droppings, and air pollution. Great for plants, not for drinking without serious filtration and treatment.
Prevent stagnation: Use your water regularly. Stagnant water can breed mosquitoes and smell bad. If you won't use it often, keep it covered and screened.