The volume of storm water discharge used for calculating all user charges shall be based upon the Equivalent Residential Unit.
(a) Single-Family Residential - The volume of storm water discharge shall be determined by a survey of impervious area of such structures representing neighborhood throughout the city. Impervious areas to be calculated shall include, but not be limited to, roofs, walkways, patios, driveways, and parking areas.
Upon calculation of the impervious area square footage, an average shall be determined. This averaged square footage shall be applied to all single-family residential properties, and shall represent an Equivalent Residential Unit (ERU). For example one ERU = xxx square feet.
(b) Multi-Family Residential - The volume of storm water discharge shall be determined by applying the ERU to each residential unit where each unit is billed for utilities separately, or where the units are billed jointly, by dividing the total impervious area of the residential property, as surveyed and calculated by city personnel, by the ERU to determine the number of ERU’s (volume) discharged into the public storm drainage system.
(c) Commercial, Industrial and Institutional or Other Public User - The volume of storm water discharge shall be determined by a survey of the subject property by city personnel and a calculation of the impervious area shall be divided by the Equivalent Residential Unit (ERU) to determine the number of ERU’s (volume) discharged into the public storm drainage system.
(d) Vacant Structure - The volume of storm water discharge shall be determined by one of the above methods for all vacant property based upon its most recent use.
(e) Detention ponds, which detain discharge of storm water into the public storm drainage system, shall not reduce the calculation of impervious area.
(f) Retention ponds, which do not discharge into the public storm drainage system, shall cause a reduction in the calculation of impervious area proportionate to that area which drains to said retention pond. This reduction shall be at the sole discretion of the City Engineer.
(g) Property surveys and calculations of impervious areas shall be the responsibility of the City Engineer.
(h) Final determination for the method and manner of storm water discharge volume shall be the responsibility of the City Engineer.
(i) Minimum Charge - The storm water drainage charge shall not be less than that amount equal to one ERU. This minimum charge applies to all users.
(Ord. 01-24. Passed 3-13-01.)