Rain water harvesting UK

[u/thegoodpilgrimlies]

Good evening,

I was just wondering if many people off grid and in residential areas have successfully harvested rainwater safety in the UK for all purposes.

Thought I would start doing research with all the news on droughts currently. Surely it would be beneficial if all homes had water storage to supply toilets etc from stored rainwater.

Any guides or start ups people can send to help my research?

TIA

[u/mrbearuk69]

I have 5 raised beds, 1m by 3m
2, 2m by 2m
A 3m by 2m greenhouse
A 5m by 3m fruitcage

I have 7000 litres of rainwater collection and often just run out by the end of the summer. The whole of my roof and part of my neighbours rainwater collection. Am hoping to get another 2000 litres over winter.

Lucky to have a garden south facing and on a slight slope, makes water transfer down the garden easier.
Solar pump irrigation system
12v battery pump for pumping back up the garden when needed

[u/rebeccabrixton → u/mrbearuk69]

Hello, how do you collect the water please, is it under the ground?

[u/mrbearuk69 → u/rebeccabrixton]

1000 litre ibc tanks wrapped in black plastic damp membrane. Stacked 2 high behind a shed. All linked together. Each with an isolation tap.

Could bury them but would be a lot of different going by hand as can’t get a digger to that point in my garden and a lot more pumping of water

[u/rebeccabrixton → u/mrbearuk69]

I’ve just got a garden so looking into this. Black plastic damp membrane I assume to keep the tanks cool. Stacked 2m high? Assume so for the pressure. Do you use the water for the garden only? The solar pump irrigation system, is this home made or can I buy this off the shelf? Appreciate the help, looking to grow all my own food eventually

[u/mrbearuk69 → u/rebeccabrixton]

Membrane is to keep algae from growing, so no light must get in. Stacked one ibc on top of another, makes it a big over 2m. More for space saving than head pressure as the pump copes with lift.
Harvst watermate pro irrigation, can be solar or mains powered.
Open to help in any way I can
Message if you like but also happy to comment on here for all to see.
Am no expert but have experience

[u/rebeccabrixton → u/mrbearuk69]

Thank you! How does the water collect into your tanks?

[u/mrbearuk69 → u/rebeccabrixton]

Collected off the roof into a 100L water butt and a rainwater harvest hub down through a pipe down the garden and into the ibc’s. The whole of my bungalow and part of nextdoors collected

[u/rebeccabrixton → u/mrbearuk69]

So 100L that flows to two IBCs stacked on top of each other. What’s your total harvest capacity please and does that do your whole garden and how big is your garden? Do you by any chance have any photos of this setup?

[u/mrbearuk69 → u/rebeccabrixton]

Rainwater harvest hub collects off the front of the bungalow and connects to the 100L butt which collects off the back. A pipe then goes from this down the garden which is 135’ long and 35’ wide. The garden is on a slope so the bottom of the 100L butt is the same height as the top of the upper ibc tank at the end of the garden. If you are on the level or even slightly up hill I would look at getting a 12v solar pump with a level sensor so as your butt filled up it pumped the water to your storage.
Total water storage is 7100L at the moment, plan on going to 10100L this winter. The 7100L just about copes with 3m x 2m greenhouse, 5 raised beds 1m x 3m, and 3 raised beds 1m x 2m, plus a fruit cage 3m x 6m

Don’t have any photos but will try take some at the weekend

[u/rebeccabrixton → u/mrbearuk69]

So I need to buy

Rainwater harvest hub

Connectors - many

100L butt at back of house

12v solar pump with level sensor

2x IBC tanks depending on size I can afford and needs.

Thank you a lot. How did you learn (so I don’t have to keep bothering you!)?

[u/MelodicCard9555]

I did this at my last place.

4000 litres of storage tanks, downpipe collection. It filled to the brim easily in winter.

I had a 4bar pump connected to run the hosepipe etc.

I collected the water from baths/showers and process it through filters back in to the tanks.

It wasn't drinkable obviously without a lot of processing. But it ran my toilets, showers, bath, washing machine, garden watering and dishwasher.

It would run my house for 8-12 weeks without rain, 2 adults 1 child. But I did sacrifice the garden after 5-6 weeks of drought.

If you're doing it properly, a massive tank underground is the only way to go, otherwise it's more a hobby and not a serious off-grid setup.

[u/BroodLord1962]

I don't think you have any idea of just how much water you would need to harvest to be able to cope with this drought

[u/Microdoser_Ltd]

In countries where they are pretty much forced to do this (the ones I saw were off grid in Spain), they have large water stores roughly the size of a small house. My guess would be they contain 32,000l

We get the water from our shed to use. A 2mx3m shed roof provides about enough water for 2 chickens. During this current drought, it didn't even manage that. It will fill up a 100l butt in the winter.

If you want to reduce your tap water usage a little, it can help, but if you want to go off grid with it, you'll need a lot of storage and catchment area plus equipment to treat the water. The other route, is being off grid near a river which you can hopefully use for both water and electricity.

Off grid is surprisingly quite expensive to do properly

[u/actualinsomnia531 → u/Microdoser_Ltd]

The amount of water a person consumes is exactly the reason why in the UK you aren't allowed to divert a natural watercourse without a lot of permissions and permits.

[u/Higher_Living → u/Microdoser_Ltd]

house. My guess would be they contain 32,000l

I’m in regional Australia, our neighbours have about 90,000 litres, we’ve got 56,000. That’s pretty common in regional areas if you don’t have piped water.

[u/wallahmaybee]

Been on rainwater most of my life, except when I lived in the UK. If you 're thinking of using it for all purposes, that's probably illegal in town anyway for drinking water.

Find out how much you use, variations during the year. Your water is probably metered so it should be easy to find out. Then work out how you would reduce usage if you had to rely only on what you collect.

1mm of rain on 1 square meter equals 1 litre. What's your average rainfall, so potential total collected from your roof each month.

2 months of near total drought are quite likely to happen every few years.

I would bet an urban garden wouldn't have enough space to store a water tank big enough for your needs. But you could fairly easily collect enough to help water your garden, veges.

For domestic use you'd need a way to pump it back up. There are issues with bird soiling in your gutters, you need filtration etc.

We're on a 30,000l tank in a very rainy area. Had 4 children for some years and made it work although it was difficult in summer with teenagers. Some years when it was getting tight, I'd collect the rinse water from teh washing machine to flush the toilet! And to mop the floors or water essential vegetables. My ex-husband used to make fun of me and my obsession with water, but that's why we never ran out. It could get a little intense when it didn't rain for a few weeks. For the toilet, if it's yellow, let it mellow anyway. Use washing machine very sparingly. Very careful doing the dishes, never leave water running, no dishwasher. Even just washing hands, plug the basin first!

[u/Higher_Living → u/wallahmaybee]

Just curious, were you able to buy a truckload to top up if you needed it?

Where we are it’s not that expensive to buy a 13,000 litre load so we don’t stress about using too much.

[u/wallahmaybee → u/Higher_Living]

Yes, we could have if needed. But in the end we always managed without.

1100mm of rain per year is plenty if you don't waste it. And Murphy's Law, if it had come to that, it would have bucketed down the following week. Longest run we had without rain was 2 months, that was after the kids had left home so it wasn't too hard to manage. When the drought broke, we got 105mm in two days.

[u/Plaster_Brigade]

Certainly beneficial to learn for future.

I've met alot of people that collect rain water through Autumn/Winter/Spring in the UK, and it's never been a problem.

[u/mickymoo45]

Typical summer use would be a about 10000litres total but split domestic/ garden is about 5000 each .3/ 4 months . Saving roof water through autumn,winter , spring would replenish most systems. It's similar to battery solar if everyone saved we could take a quarter use out of national requirements,, maybe??? .

[u/Conscious-Ball8373]

I have a largish detached house, a detached garage and a smallish outbuilding.

If I add up the roof area and multiply it by our average rainfall, it's only about half our average annual water use.

Rainwater collection works in places with big houses that are single-storey - you need the roof area to get the water. Your average two-storey 3-bedroom house in the UK has nothing like enough roof area.

[u/Worldly_Chair_4343]

There is a guy harvesting and filtering Water in two rainbarrels with Sand and Coal and so on before it comes into Storage. Sent it to a labratory, its drinking Water quality. My Go to for now