Passive irrigation

[Robert Rickey]

I tried to calculate how much water I would need to sustain our veg and fruit garden in a three week drought, and it is a hell of a lot. I have looked at what size water butts we could reasonably live with. Then I researched the idea of storing the water in the ground! We have raised beds on a sloping site, so waterlogging should not be a problem.

Here is the idea:

1. Install 400 liter water butts
2. Fill the butts
3. Take the overflow into a “big pipe” – 100mm? underground to little standpipes at the ends of the beds
4. Connect leaky pipes to the uphill side of the beds
5. Install a shutoff to the irrigation in case of really wet weather – overflow goes to storm drain.

I have a poor understanding of hydraulics, so I have no idea if this will work. The fall to the top bed is about 750mm and to the bottom 1500mm. There's a lot of materials and digging to find out experimentally. See attached drawings for more information about what is involved.

Any advice or reference works welcome!

[Tom Foster]

I have 2 x 2000 litre ex-orange juice barrels (4 tonnes of rainwater) up the slope, providing 4-6m head to leaky pipes in 6.7 x 3m polytunnel. Lasts about a week in dry summer! Ordinary leaky pipes need more pressure than that, so am looking for lo pressure replacements, and tripling the storage.

[Robert Rickey]

Where can I find extra ordinary leaky pipes, then? Garden hose and a hand drill?

[Tom Foster]

Going to consult online leaky pipe specialists – any day now! Tell me what you find out?

[Robert Rickey]

The main difference in our schemes is that I want the 4000 liters stored in the ground. I have no idea if the rainfall patterns support this – the above ground store would be used lightly and in emergency only. I may pay you a visit since I'm just in Crediton!

[Author]

Posts