This section applies to any construction, alteration, or improvement performed on sites where existing land use is commercial, industrial, institutional, or multifamily residential and existing site impervious area exceeds 40%.
Stormwater management plans are required by Rock Hall for all redevelopment, unless otherwise specified by watershed management plan developed according to this chapter. Stormwater management measures shall be consistent with the Design Manual.
Reduce impervious surface area within the limit of disturbance (LOD) by at least 50% in accordance with the Design Manual;
Implement ESD to the MEP to provide water quality treatment for at least 50% of the existing impervious surface area within the limit of disturbance; or
Alternative stormwater management measures may be used to meet the requirements of Subsection B of this chapter if the applicant satisfactorily demonstrates to the approving authority that impervious area reduction has been maximized and ESD has been implemented to the MEP. Alternative stormwater management measures include, but are not limited to:
Off-site BMPs to provide water quality treatment for an area equal to or greater than 50% of the existing impervious area; or
A combination of impervious area reduction, ESD implementation, and an on-site or off-site BMPs for an area equal to or greater than 50% of the existing site impervious surface area within the limit of disturbance.
The approving authority may develop separate policies for providing water quality treatment for redevelopment projects if the requirements of Subsections A and B of this chapter cannot be met. Any separate redevelopment policy shall be reviewed and approved by the Maryland Department of the Environment and may include but not be limited to:
A combination of ESD and an on-site or off-site BMP;
Retrofitting including existing BMP upgrades, filtering practices and offsite ESD implementation;
Stream restoration in the same twelve-digit watershed as the proposed development and an area restored equivalent to the area required for treatment;
Pollution trading with another entity;
Payment of a fee to be dedicated to a water quality improvement project in lieu; or
A partial waiver of the treatment requirements if ESD is not practicable.
The determination of alternatives available may be made by the approving authority at the appropriate stage in the development review process. The approving authority shall consider the prioritization of alternatives in Subsection D of this chapter after it has been determined that it is not practicable to meet the 2009 regulatory requirements using ESD. In deciding the alternatives that may be required, the approving authority may consider factors including but not limited to the following:
Whether the project is in an area targeted for development incentives such as a Priority Funding Area;
Whether the project is necessary to accommodate growth consistent with the Comprehensive Plan; or
Whether bonding or other financing mechanisms have been secured based on an approved development plan.
Stormwater management shall be addressed according to the new development requirements for any net increase in impervious areas.