Hello, I am an environmental engineer sharing my design for a ~300 gallon IBC tote rainwater collection system. What makes this different and beneficial for self-sufficiency is the low cost per gallon. This tote also provides a large enough storage tank to use a dedicated irrigation pump for reuse. You could make this as simple or as complex as you wanted to.
IBC totes are frequently used for storing and transporting food grade materials, so there is an aftermarket for cheap used totes, you just have to verify what they were used for. I got this 275 gallon tote off of marketplace for $100 USD. It was previously used to transport food dye. They are highly durable because they’re built out of HDPE and galvanized steel.
Other Materials:
Leaf filter, from $10 to $70 - my preference is the Leaf Eater Advanced ($66)
Downspout diverter, my preference is Earth minded Flexifit diverter ($20)
PVC pipe and valves, figure $50
Total entry cost including tank: $180 - $240
Optional:
Lid adapter for two inlet ports $10
1 HP irrigation pump $140
Discharge splitter $10
Wi-Fi controller $30
Piggy-back Level float, alternative controller $50
Ozone injector to keep the water fresh and odor free: $400 (luxury) JED Engineering model 203
Fair enough, and with underground tanks you need a way of getting the water out again, which usually means pumps, which adds expense and maintenance, and you have to make sure the water is really clean.
Using greywater is sensible. Switch your soaps to nature-safe ones to help - https://www.faithinnature.co.uk/ make some good hand, shampoo and dish-washing soaps. I really like the solid shampoo bars from here: https://www.soapnuts.co.uk/products/bulk-mixed-shampoo-selection too.
You can also get filters to help get rid of the impurities. One system is using a reed bed if you have space: https://www.reedbeds.co.uk/
https://www.hockertonhousingproject.org.uk/ has such a system as part of their pond system. We went on one of their open days a few years ago, which was really interesting.
Reed beds are an interesting idea, I had initially thought of having it poured directly into an earth channel or two along my garden so it soaks in almost immediately and avoids having any standing water as I had heard storing greywater can rapidly get unpleasant. I suppose as long as it is filtering more than it goes stagnant then it should be alright.
Collecting it should be ok, got 2 pipes going out the house, one from the bathroom and other kitchen and they are next to each other. I think bathroom (not toilet, that is separate) is probably cleaner and contains less soap. Realistically it would only be necessary during times of drought anyway, now we are going into autumn there is already enough water from rain. Which should also help flush out anything that could build up from the greywater.
Sounds good. Yes, I wouldn’t want to use toilet water, but bath and shower water would be ok. Just remember when you’re cleaning the bath with bleach or similar, send that water back to the normal drain!
Kitchen water from washing up should be fine, just watch that you don’t put too many fats down the drain, as it could smell and attract rats etc, possibly (just guessing, but I would think it would be a bad idea).
Also, i guess you need to think about the temperature - you don’t want hot water near your plants!
Next year I should think about doing the same thing with shower/bath water at least, that is probably the cleanest waste water.
If you just want to use an earth channel or similar, maybe have a look at “Field Drains”, eg: https://store.jdpipes.co.uk/land-drainage/ ? although you might have to get access to them now and again to clear the holes.
To be fair excess fats are bad for the normal drain too. Temperature is a good point, my initial idea was that the channels would be along the grass paths so if a bit of grass dies by the opening it isn’t really a massive concern. By the time it soaks in any real distance it should be cooled by the surrounding soil.
Bath/shower usually is the cleanest source to go for first, the pipes are next to each other for me. Either way I would set it up so that they can be easily removed when I don’t need the water going onto the garden.
Do need to check how flat the area is, exit point from my house is pretty close to the ground so a slight elevation change could be a problem.