§ 28-228. Permanent structural best management practices.

(1)

The applicant shall use permanent structural best management practices in order to achieve the applicable minimum control requirements as specified by the most current version of the NPDES General Stormwater Permit for Construction Activity. The applicant shall provide justification for the best management practice(s) selected.

(2)

The applicant shall install or construct all permanent stormwater management facilities necessary to manage increased runoff so that the peak stormwater discharge rates from the stormwater treatment basins do not exceed the predevelopment twenty-four (24), two (2) year, ten (10) year and one hundred (100) year peak stormwater discharge rates. The predevelopment stormwater discharge rates shall be based on the use of the property during the past ten (10) years. All calculations and information used to determine the peak stormwater discharge rates shall be submitted by the applicant with the grading permit application. Accelerated channel erosion must not occur as a result of the proposed land disturbing or development activity. In lieu of installing all or a portion of the required permanent stormwater management facilities, an applicant may agree to make an in-kind or monetary contribution to the development and maintenance of a community stormwater management facility that is designed to serve multiple properties that shall be addressed as part of a development agreement.

(3)

The following permanent stormwater management practices must be investigated in developing the stormwater management portion of the SWPPP:

(a)

Protect and preserve as much natural or vegetated area on the site as possible;

(b)

Minimize impervious surfaces;

(c)

Direct runoff to vegetated areas rather than to adjoining streets, storm sewers and ditches;

(d)

Flow attenuation of treated stormwater by the use of open vegetated swales and natural depressions;

(e)

Utilize stormwater wet detention facilities (including percolation facilities); and

(f)

Reduce the need for permanent stormwater management facilities by incorporating the use of natural topography and land cover such as natural swales and depressions as they existed prior to the land disturbance activities to the degree that they can accommodate the additional flow of treated water without compromising the integrity or quality of the body of water.

(Ord. No. 2009-13, § 2, 10-13-09)