Rainfall is expected to become more common and more intense, followed by a prolonged drought with a ban on irrigation, etc. We are not used to this and it is noticeable not least in urban environments with congested and undersized water supply networks with floods as a result (during the heaviest rainy periods). Expanding only the water and sewerage networks is a bit like turning a blind eye to the cause itself and only doing something about some of the consequences. We need to do more and, above all, think more preventively!
We got simple systems where you connect the downpipe including a filter to a decorative barrel.
We also got more advanced systems for undergound tanks where you can connect toilets, wateringtaps for gardens, laundrymachines, water for cleaning...