§ 32-178. Minimum Stormwater Control Requirements.

(a)

The minimum control requirements established in this Section and the Maryland Design Manual and the Prince George's County Design Manual are as follows:

(1)

Planning techniques, nonstructural practices, and design methods specified in the Maryland Design Manual and the Prince George's County Design Manual shall be used to implement ESD to the MEP. The use of ESD planning techniques and treatment practices must be exhausted before any structural BMP is implemented. Stormwater management design plans for development projects subject to this Division shall be designed using ESD sizing criteria, recharge volume, water quality volume, and channel protection storage volume criteria according to the Maryland Design Manual and the Prince George's County Design Manual. The MEP standard is met when channel stability is maintained, 100% predevelopment groundwater recharge is replicated, non-point source pollution is minimized, and structural stormwater management practices are used only if determined to be absolutely necessary.

(2)

Attenuation of the 2-year, 10-year frequency storm event for downstream erosion exist and/or attenuation of the 100-year frequency storm event for downstream flooding exist are required according to the Maryland Design Manual and the Prince George's County Design Manual and all subsequent revisions when the Department determines that additional stormwater management is necessary because the receiving channel and/or conveyance system are determined inadequate.

(3)

The Department has the authority to require more than the minimum control requirements specified in this Division if hydrologic or topographic conditions warrant or if flooding, stream channel erosion, or water quality problems exist downstream from a proposed project.

(b)

Alternative minimum control requirements may be submitted for approval to the Administration. A demonstration that alternative requirements will implement ESD to the MEP and control flood damages, accelerated stream erosion, water quality, and sedimentation will be required by the Department. Comprehensive watershed studies also may be required.

(c)

In addition, where the development activity is located within a Chesapeake Bay Critical Area Overlay Zone, the minimum stormwater control requirements shall include all the requirements of Subtitle 5B.

(d)

Concept and design plans shall be consistent with adopted and approved watershed management plans and flood management plans as approved by the State Water Resources Administration in accordance with the Flood Hazard Management Act of 1976 (Title 8, Subtitle 9A of the Natural Resources Article), where applicable.

(e)

Best management practices information for new developments and redevelopments shown on the approved final stormwater management plans, where applicable, shall be submitted by the Department for submission to the Administration under the requirements of the NPDES Program. The owner and/or applicant shall provide this information to the Department.

(CB-15-2011; CB-27-2014; CB-36-2015)