Stormwater Utility charges in the City of Marion are based on the Equivalent Residential Unit (ERU). One ERU represents the average impervious area of a residential unit in the City of Marion, determined to be 2,791 square feet. The number of ERUs assigned to each City parcel corresponds to the amount of stormwater runoff generated by the parcel. Specifically, the number of ERUs assigned to a parcel is based on the number of living units for residential properties, and the measured or calculated impervious area for non-residential properties. Parcel charge is the product of the number of ERUs assigned time the ERU charge rate, plus a monthly service charge.

Some non-residential customers in the City of Marion may be eligible for credits or adjustments to their stormwater utility bill. Credits and adjustments are defined as follows:

A CREDIT is a reduced ERU multiplier, awarded to customers who can demonstrate that they have somehow reduced the City’s cost of providing stormwater management service to their property. A customer who receives a credit will have their ERU charge reduced by at least 1% and at most 65%.

An ADJUSTMENT is a change in the number of ERUs assigned to a parcel. Adjustments are made based on the availability of more accurate or up-to-date measurement of the amount of impervious surface on a parcel. A customer who receives an adjustment may have the number of ERUs assigned to their property, and the resulting parcel charge, either reduced or increased.