A.   Drainage Policies:

   1.   The stormwater drainage system shall be designed to pass the peak stormwater runoff received from upstream and from the subject property for storms with durations up to twenty four (24) hours and return periods of up to one hundred (100) years.

   2.   All development, redevelopment and earth changes shall be constructed so that it will not increase the frequency of flooding or the depth of flood flows for any storm, up to and including the twenty four (24) hour 100-year storm.

   3.   Peak flows shall not be increased at any location for any storm, up to and including the twenty four (24) hour 100-year storm.

   4.   Regulation of peak flows to allowable levels, as determined by subsections A2 and A3 of this section, shall be achieved by on site or off site storage and/or other water management facilities as provided in these standards.

   5.   Subject to requirements for a drainage plan or earth change permit and of the city drainage standards, downstream conveyance may be improved or easements obtained for inundated areas to compensate for increased flow depths if such improvements comply with the policies of this chapter.

   6.   All development, redevelopment and earth changes shall be constructed so that it will not cause harm to other properties as a result of concentrating flows.

   7.   On site stormwater control may not be required for sites less than two and one-half (21/2) acres in size if it is determined by the city engineer that stormwater runoff from the site will not cause adverse effects as described in this chapter. The city engineer may request that the applicant provide such information as required to make this determination.

B.   Erosion And Sediment Control Policies:

   1.   All development, redevelopment and earth changes shall be designed, constructed and completed in a manner which minimizes the exposure of bare earth to precipitation.

   2.   All development, redevelopment and earth changes shall be constructed only if appropriate sedimentation facilities are installed and maintained throughout the construction period.

   3.   All development, redevelopment and earth changes shall be accompanied by best management practices for controlling sediment and erosion so as to minimize the amount of sediment leaving the site. (2010 Code § 22-141)

Regional detention systems may be permitted and are recognized as one of the preferred methods of providing stormwater control. These systems may be designed to control the fully urbanized flows so as to permit the maximum use by developments in lieu of constructing small, on site detention. (2010 Code § 22-142)

Public or private title, ownership and maintenance of detention and drainage facilities required herein shall be determined by criteria established by and contained in the city drainage standards. Regional detention systems shall be owned, maintained and operated by the city. (2010 Code § 22-143)