Water Tanks, page-122

When you have a 135000 lt tank like serria has you probably are not going to have it right next to the house, yes I did mention before that there are lot's of things that would change the design of the system.

I can see how a sediment trap works, would not stop leaves as they float (hence the leaf basket/strainer) but any thing that doesn't float gets dragged along the bottom of the pipe and falls into the sediment trap.

Water corp do use similar systems and Road drains work on the same principle, hence why council has to come and clean them out from time to time