A. Except as provided herein, stormwater detention shall be required for proposed construction and/or development that will increase the existing amount of impervious covering on-the property on which the construction and/or development is proposed. No building permit, use permit, encroachment permit, or other permit or license for proposed construction or land development that requires provision of stormwater detention in accordance with this section shall be issued unless there is included within the plans submitted to the city, proper and adequate plans for providing the required stormwater detention in accordance with the city's Public Works Construction Standards.
B. New construction and/or development projects for which information is made available to the City Engineer demonstrating that the project is consistent the criteria listed below are exempt from providing stormwater detention:
1. The project will not result in or add to surface stormwater flows within the city that exceed the criteria established in the City's Public Works Construction Standards, and
2. The project site is tributary to existing city storm drainage facilities which provide flow restriction and/or detention within the City, and the proposed project will not increase the peak rate of flow discharged from the city storm drainage system, or
3. The project site is tributary to existing storm drainage detention facilities, and the proposed project or improvement is consistent with the design parameters used for the design of the detention facilities, or
4. The project site is zoned for residential uses and:
a) If undeveloped, the site was legally created before 1990, or
b) If developed, the proposed improvements will not cumulatively increase the structural coverage by more than 500 square feet from the structural coverage which existed on January 1, 2000, or
5. The project site is zoned for non-residential uses and alteration, modification, improvement or change that will not increase the computed composite "C" value (runoff coefficient) by more than 5% from the computed composite "C" value for the conditions that existed on the site on January 1, 2000.
(Ord 694,2000)