[Closed] rainwater harvesting

Get a water butt with downpipe attachment from Wickes/B&Q?

Water butts and one of the karcher washers that works with an unpressurised supply, you don't need anything fancy unless you;r looking to start doign stuff with plumbing inside the house.

I have 800 litres of storage in 2x 100 litre waterbutts and 3x 200 litre Olive import barrels.

All linked together with a single outlet. Mainly for veg bed watering.

Karcher pressure washers are approved for connecting to water butts.

I plumbed the house with a second cold water supply for rainwater to two of the toilet cisterns and the dishwasher and washing machine. However the capital cost of fitting a water regs approved water handler (long story short its all about air gaps and cross contamination and the fact that I dont have the ability to run a cistern in the roof) and a 2,000 litre storage system would only have got payback in 20yrs plus.

So instead Im considering doing something more basic using an IBC (1,000 L) and a negative head pump when one comes up on ebay for a decent price. I can legally manually fill the IBC with mains water if storage gets low from the outside hose. That would cost about £150 to set up and should save about £50 pa.

You can run a pressure washer or small submersible pump from a water butt (to power a hose). In general, the carbon impact of running pumps is greater than the carbon saving from not drawing mains water, so low tech (gravity fed) is the way to go from the eco point of view.

We have two water butts, running off the rainwater down pipe, but I also fitted a diverter onto the bathwater downpipe so I can collect that instead during a dry summer (ha!).

Rainwater is completely soft so you'll find you need less detergent for cleaning your bike or car.

Do some basic maths on the average rainfall in your area and the rough size of your roof. You probably have a lot of potential if you can intercept more than one down pipe with simple water butts.

Can you change the plants or the design of the garden to reduce the need for watering as well? Or change the ground around trees so the water goes to where it is needed. Reducing the need will make what you capture go that much further.

My house had it built in from new. 4000 litre tank in loft above kitchen, collector from main roof with filter and overspill diverter to drainage. Just higher than main toilet cistern for low pressure feed to it, 10ft above other toilet and directly above clothes washer. Slave cistern with two (different height)ball valves at outlet from main storage tank means that if storage is empty, supply can come from mains.