You would still need to pay the utility fee because most surfaces, including grass, generate stormwater runoff. Native prairies and woodlands still generate runoff. Grass just generates less runoff than impervious surfaces. The City is using the impervious area to determine each property’s use of the system. This methodology is used by many other cities for their stormwater utilities. If the City were to do an actual drainage analysis of every property (that would be over 46,800 properties!), the administrative cost would be high and the general outcome of that effort would result in a cost distribution similar to using impervious area information.