Re: Make your own laundry soap?
Grey water is water that has been used either from your shower, washing machine, kitchen sink etc and contains contaminates from the soap or detergents - hence to need to be careful about what you use.
Not the same as storm water collected off your roof which of course in many places is used as drinking water. I have 5000 litre water tanks too which are used to collect rain water, eventually I will connect them up so I am not using drinking water to flush the toilet (which is quite a stupid use of good water when you think about it) but at the moment they are used to water the garden only.
Unlike the UK no one puts rain water into the sewers (infact it is illegal) Storm water is a separate system which end up in the ocean or rivers. During the drought it is a matter of much angst that this fresh water is being wasted when it could be diverted and used as non potable water (ie not drinking water) or even refined to drinking water.
Again unlike Europe the 'yuck' factor has prevented even tertiary treated sewage water being used for anything other than a few industrial purposes even though the solids are used for fertiliser.