I guess not for drinking. OP is planting trees, so assumably has land where some kind of forestry/agriculture is in being carried out. That needs quite some water. (eg. freshly planted trees need irrigation to have a fair chance of survival)
Also washing, showering can be done with rainwater if you are really a minimalist.
You shouldn't be washing your car in the driveway. Even if you use environmentally friendly soap, or no soap, the water coming of the car isn't exactly clean.
Professional car wash places are required (depending on location) to collect and dispose of their waste water in a safe way. When you wash the car in the driveway, the waste water will either go into the ground or the storm drains, neither of which will ensure that the waster is cleaned before reentering the environment.
I solved this problem in minimalist way - I wash my car maybe twice a year. It sits in my driveway in rain anyway because my garage is waiting for some spare time so that I can finally reuse all that pallets I collected since last year (mostly clean pallets I've already made some nice yard furniture for myself and family, all those pallets already have planned use but I don't have enough time).
For moving around town i just walk, maybe sometimes I use my 20yr old bike. My car is used only to travel from my town to nearest city, because it takes 3x more time to go with bus->train->taxi to where I need to go and is a little more expensive. Then it sits idle 5 days. It's more like 1.2tons and is not that guzzling, 7L/100km. Diesel or hybrid would be guzzling even less, but they break more and/or are more expensive. I'm not a eco freak, I do what I can, but some people really do need to own some transport. In Poland, if I see someone with a big pickup, it typically means he actually DO uses it to pick up various things otherwise it would be too inconvenient to own such a big car.
Yup, I worked at a car wash and the water coming off of cars is absolutely disgusting. Had to wear some sort of hazmat type suit to clean the trench as we called it.
We're gonna preserve our quality of life one exception at a time all the way to societal collapse, it seems. How much quality of life can we have when billions are on the move due to heat dead zones, collapsing one government after another?
>There are lots of "grey water" uses that don't require drinkable water, like watering plants, flushing toilets.
Yes. I've heard/read grey mentioned many times in permaculture articles.
I like the fact that permaculture takes a systems or holistic approach.
Another nice, small but useful example of permaculture design is the concept of guilds, when it comes to planting crops around a house.
They plant by category, in concentric bands called guilds, with the guild nearest to the house having most commonly used plants such as herbs, then vegetables, then grains, then fruit trees, etc.
So you have to walk less to tend to or harvest them.
Edit: I may have used the term "guild" incorrectly.
The Wikipedia article on permaculture uses it differently, under the section "Guilds".
Yeah you're talking about zones. Zones refer to the intensity of maintenance / how often you'll be harvesting from them. Zone 1 around the house is most frequent - zone 5 is way in the jungle where you harvest wild guavas once a year.
Guilds are about companion planting - they're combination of plants that form a small ecosystem where they provide benefit to each other. E.g. comfrey is often used around fruit trees to break up subsoil (it has very long taproots, to 10 feet or so), and as a prolific mulch producer (cut it back every couple months, and chop and drop the leaves in place). Nitrogen fixing plants are common, as a way of providing nutrients. Etc.
>> 5. Collect rain water and/or use less water
>
> Not sure about that -- With modern pollution rain water is not likely to be safe to drink (depends on your location)
Water availability is also very different from country to country, region to region, and even town to town. How your water usage affects the environment depends on so many things.
I collect rain water but use it on the veggie garden. So either it is safer because I ma not drinking it directly OR it is worse because the planet are bio-accumulating it. I don't know.
At my parents' house rain water was collected in a well and that was used for things like flushing toilets and watering plants. This was already in place 30+ years ago mainly cause it's "free water" (apart from the cost of building the well and the pump)
Over here, your water bill has 2 components, the price of the fresh water and the price of the waste water. Waste water is at least as expensive per m³ as fresh water, sometimes more than double. If you are using rain water, you save on the fresh water price, but you have to still pay for the waste water. And since waste water price is calculated from your fresh water consumption, you either have to have a second meter for the rain water (expensive) or you pay for an estimated amount of rainwater calculated from the roof area you are collecting from. Also very expensive, because the estimate is always not in your favour.
So not really "free" at all, and rather expensive enough that nobody does it...
This also depends a lot on your locality. If you live in an area where septic tanks are allowed you don't have to pay for city sewer usage.
You can also skip that entirely with a composting toilet. Again depending on your local laws, gray water can often be drained directly outside, potentially through a leech field if required. Plenty of areas allow this for specific uses like washing machines, the only reason it can't be done with standard toilets is because of the solid waste.
Also washing, showering can be done with rainwater if you are really a minimalist.