Charles County, MD Article VI Redevelopment

§ 274-17 Design requirements.

Q_p and Q_f are not specifically excluded and may be required if the County Engineer determines there are existing flooding or erosion problems on downstream properties associated with the existing development.

A. Unless otherwise specified by a watershed management plan developed according to § 274-26, Watershed management plans, of this regulation, all redevelopment project designs must be consistent with the Design Manual.

B. All redevelopment designs shall:

(1) Reduce existing impervious surface within the limits of disturbance by at least 50% according to the Design Manual;

(2) Implement ESD to the MEP to provide water quality treatment for at least 50% of the existing impervious surface within the limit of disturbance; or

(3) Use a combination of both Subsection B(1) and B(2) above for at least 50% of the existing site impervious surface.

C. Alternative stormwater management measures may be used to meet the redevelopment requirements of this chapter, provided that the developer satisfactorily demonstrates to the County Engineer that impervious surface reduction and ESD have been implemented to the MEP. Alternative stormwater management measures include, but are not limited to:

(1) An on-site structural BMP;

(2) An off-site structural BMP to provide water quality treatment for an area equal to or greater than 50% of the existing impervious surface; or

(3) A combination of impervious surface reduction, ESD implementation, and an on-site or off-site structural BMP for an area equal to or greater than 50% of the existing site impervious surface within the limits of disturbance.

D. When the developer has demonstrated to the County Engineer that the requirements of Subsections B and C cannot be met, the County Engineer may approve reasonable alternative stormwater management measures, including but not limited to the following:

(1) A combination of ESD and on-site or off-site structural BMPs;

(2) Retrofitting, including existing BMP upgrades, filtering practices, and off-site ESD implementation;

(3) Participation in a stream restoration project;

(4) Pollution trading with another entity;

(5) Payment of a fee-in-lieu; or

(6) A partial waiver of the treatment requirements if ESD is not practicable.

E. The determination of what alternatives will be available may be made by the Department at the appropriate point in the development review process. The Department may consider the prioritization of alternatives in Subsection D after it has been determined that it is not practicable to meet the 2009 regulatory requirements using ESD. In deciding what alternatives may be required, the Department may consider factors including, but not limited to:

(1) Whether the project is in an area targeted for development incentives such as a priority funding area, a designated transit-oriented development area, or a designated base realignment and closure revitalization and incentive zone;

(2) Whether the project is necessary to accommodate growth consistent with Comprehensive Plans; or

(3) Whether bonding and financing have already been secured based on an approved development plan.

F. Stormwater management shall be addressed according to the development requirements in the Design Manual for any net increase in impervious surface.