Georgia Water *Treatment*???  GWT is now the Georgia industrial representative for Orival filters.  I've used these the past few years as my standard self-cleaning 5-10 micron filter.  For rainwater, we used them for flows from 5 - 150 gpm.  But Orival has standard products up to 24" and 10,000 gpm, with custom manifolds bigger than that.

You can catch a glimpse of one of these in action here:
http://www.youtube.com/watch?v=Dwizpy-wXis

www.orival.com