WATER harvesting, whether grey-water or rainwater, does not have to be expensive. Nor does it have to be as complicated as it seems, only to be done by a professional. There are many different levels of approaches to water harvesting, the most simple being to use what you already have to make a difference.
To re-use our greywater, a tip I have had the privilege of sharing is leaving our bathwater in for rinsing the toilet and washing hands/floors etc.
Another I have started to do is to collect my laundry’s rinse water in a bucket, which I then add to my next washing cycle. I also collect the washing cycle’s water, which I then use for our vegetable garden.