That's the state standard for new sewer systems in many locations in the United States as well. It's also actively subsidized through a complicated system of gr

That's the state standard for new sewer systems in many locations in the United States as well. It's also actively subsidized through a complicated system of grants by the Federal government. The motive, however, usually isn't reuse of the stormwater runoff, but to reduce pollution. Almost all older sewers in the United States use a combined sewer system, with a CSO (combined sewer overflow) into a nearby river. So when there's a heavy rain, the system dumps the excess combined rainwater and sewage into the river. Most U.S. towns and cities are this way. Right now, whenever a system is ripped out, the combined state and local regulations and incentives usually drive the municipality to put in separate sewer systems, with the stormwater system using the old overflow site as its outlet.