Nope it is not the water that is the pollutant, it’s the soap and the runoff from impervious surfaces going into the storm drain system. I live in an area where two major river systems are under serious threats because of urban and agricultural runoff. Diverting runoff into retention ponds or following other practices that minimize or eliminate it all together are not draconian. Now I should mention the main threat our rivers face is because of Army Corps of Engineer’s policy on discharging water from Lake Okeechobee. They of course never have to show the same concern for valuable natural resources as us common folk.
The city in this instance explained how to avoid violating policy and the changes needed are not that drastic, don’t wash cars on the pavement, divert it to a retention area. This is not a case of nonsense rules made to oppress innocent citizens and well intentioned students.
I am pretty much almost all enviro regulations, but this isn’t one of them in a densely populated area.