Equivalent runoff unit (ERU) definition
Equivalent runoff unit (ERU) means the es- timated average horizontal impervious area of a “single family home” within the City of Oak Creek. The horizontal impervious area includes, but is not limited to, all areas covered by structures, roof extensions, patios, porches, driveways and side- walks. One ERU has been determined to be 3,300 square feet of impervious area.
Equivalent runoff unit (ERU) means the statistical average amount of impervious surface area per residential parcel, in square feet, associated with parcels within the City, containing single-family, duplex or triplex units. One ERU is equal to 2,880 square feet of impervious area.