It would be more cost effective if they used “gray water” for re-use in irrigation systems and other non-potable water systems. Gray water would be sinks and baths.
Given the waste of perfectly good rain water, Sacto again opts for a very expensive and sketchy solution to a problem they contrived rather than the obvious, effective and less expensive one.
Ummm, does the majority of sewer systems separate gray and black water? no...