In this follow-up to my original video on the subject, I show you how I set up a low-cost, reliable and reusable gravity irrigation system for watering our garden.
As I had done in the previous version of this setup, I am harvesting rainwater from the roof of my detached two-car garage through a homemade 2″ PVC diverter, splitting water between a pair of 65-gallon “Rain Wizard Urn” rain barrels by Good Ideas (available from Sam’s Club, Steins Gardens and Gifts, some garden suppliers and online). The rain barrels are connected to 3/4″ CPVC pipe on a slope to the garden, where it splits into 1/2″ CPVC trunks.
From there is where the system changes from my 1.0 version. Instead of running 20 foot sections of 1/2″ pipe and drilling holes to throw water to the plants, I cut a bucket full of random lengths of the 1/2″ CPVC and used elbows, tees and 45 degree fittings to build a customized network of piping that goes to each plant individually. Each end is capped with a 1/2″ CPVC cap, which has a tiny hole drilled into it.
When the whole network of pipes is capped in this way, the water from the rain barrels fills up the pipes end to end and a uniform trickle of water delivers to each plant individually. This is a much more accurate, less-wasteful way of targeting water to the plants and reducing overspray and evaporation on hot days.
Since the pipes are all push-fit together, they can be disassembled at the end of the season and stored, and reused in subsequent years. The low pressure of the rain barrels means you don’t have to cement the pipe together. This system even can accept city water as long as you have a valve in line that can regulate the pressure. I have a quarter turn ball valve in line that I only have to open very slightly and it delivers enough pressure to water evenly without blowing out my connections. This is also a good way of flushing out any dirt or sediment that may get into the system.