North Carolina is currently experiencing a pretty bad drought. Where I live (in Cary) things are much less severe than neighbouring Raleigh and Durham- but there’s still a mandatory hosepipe ban. Blame it on the changing climate, over-expansion or whatever you want – the problem exists, has done for a while and likely will not get better.

But I decided to at least solve the local problem – essentially how to irrigate a large garden without a) getting fined; or b) spending hundreds of dollars a year on something that falls freely from the sky.

So I’ve installed a rain harvesting system – a really simple means to collect rain water and store it for those times when there isn’t enough natural water to sustain life in our garden. This is a simple concept and one that was pretty commonplace throughout history, throughout the world – but for some reason (likely convenience and aesthetics) it’s become far less common.

My goal was to be able to buffer sufficient water to be able to irrigate the garden a couple of times between rainfall. I didn’t want big ugly rain-barrels under every downspout and didn’t want the system to be inconvenient to use or maintain.

Fortunately we have a very large crawl space and our main roof’s downspout runs conveniently down the outside wall so I decided to store the barrels in the crawl space – addressing the aesthetic requirements and also reducing the chance of creating a mosquito nursery.

The first phase of the project involved building a raised platform in the crawlspace. This raised the barrels above the level where I wanted to install a tap; provided a firm, level surface and created additional “static head”. I purposely over-engineered the platform because I was concerned about the weight of the water. I currently have 3, 60 gallon barrels which weigh about 460lbs each when full and plan to add more depending on our usage.

The next stage is tapping into the downspout. A bit of Googling found a couple of ready-made downspout converters and I found this one in my local Garden Center. It’s not a great design but it seems to work OK. This one I found later seems to be a better idea but seems a strange colour (I’ve never seen green downspouts).

To link the barrels and connect to a tap and overflow – I’ve used washing machine hose instead of regular hose. Washing machine hose is kink free and long lasting but it is more expensive – I mostly used brass and metal fittings because I really don’t want leaks and don’t want to have to replace this stuff any time soon.

My configuration has one ‘master barrel’ which connects to the downspout, the overflow and the tap. The other barrels are daisy-chained using washing-machine hose and Y-connectors. The Y-connectors have shut-off valves so I can isolate barrels if I need to make repairs or extend the chain of barrels.

I raised all but the master barrel an inch because I want to be sure the master overflows before the others

The barrels are re-used food barrels (used for transporting Greek olives) and I bought them from WholeFoods for about $100 each. They are fully covered and have decent brass fittings. You can of course get barrels much, much cheaper and convert them yourself. $100 seems very expensive – I’d love to see some kind of water authority subsidy. I’d also love to see new houses built with underground rain water collection systems – seems like a complete no-brainer to me.

Finally, I fitted an outside tap (I guess I need to label it non-potable) – the “static-head” is only sufficient to water the garden downhill from the house or to fill a watering can – so not as convenient as the mains tap on the right.

So – after a bit of work and about $380 – I have managed to collect some rain water (180 gallons) – the three barrels filled in just a couple of hours during a heavy downpour; the next phase is to look into a solar powered irrigation pump that can distribute the collected water to the up-hill bit of our garden – ie. get it to “mains” pressure.