Behold, the heart of my new rainwater harvesting system. This 1000 litre food grade container cost just £30, and will hold enough water to supply the truck for about a fortnight. Thus I’ll be using less than a quarter of the average person’s water consumption. Where is the water coming from? The barn that I’m parked in front of – given our recent rainfall, the gigantic silage barn roof will fill this in no time at all. 
What I haven’t worked out yet is exactly how to filter the water as it enters and leaves the container. There seem to be thousands of available commercial filters, but I’m hoping to find something that is a)Free and b)able to be made by me.
Just as I hope to use 1000 litres a fortnight, so I will produce 1000 litres a fortnight, all of which currently runs into a small tank below the truck and gets emptied for watering crops. Ultimately, this greywater would run directly into a reedbed system, which would filter it naturally, but I’ll have to find a way to do it in the meantime.
Our water consumption is very low, for a number of reasons – firstly because we don’t use a flush toilet – the one in the truck is pee-only, and goes on the compost heap (if you want a crap, its off to the compost loo). Secondly, the hot water system heats a fairly small amount of water, so showers are hot but brief, which saves a load. Thirdly, using taps= using the pump = using electricity, so you learn to be economical in your water usage, which after a day, becomes second nature and you still get all the water you need.
Getting the rainwater system finished will be an important step – at that point we will be entirely responsible for generating our own power, dealing with waste water and sewerage, and providing for water supplies. That hopefully will be a really significant reduction in our impact on the environment.