Development Criteria

The Critical Area is divided into 3 land use management areas based on development conditions existing prior to December 1, 1985. These categories are:
Development or installation of structures in the Critical Area must avoid and minimize the impacts to sensitive environmental features of that site and provide for improvement of stormwater quality. If you believe your property may be in the Critical Area and are planning any construction on your property, contact the Department of Planning and Zoning at 410-638-3103. Planning and Zoning staff will explain the land use management area designation(s) for your property.

Habitat Protection Areas (HPA)
Planning staff can also identify the HPA recorded for your property and the surrounding area. A HPA is defined as any existing area of open water, tidal or non-tidal wetland, stream or river channel, stream or river bank or upland area of any type and size, including a reasonable protective area, within Harford County’s Chesapeake Bay Critical Area which has been determined to be of significant natural value because it contains at least 1 of the following:
  • Buffer area adjacent to tidal waters, tidal wetlands or tributary streams
  • Nontidal wetlands
  • The habitat of a species of plant or animal listed by state or federal authorities as endangered, threatened or in need of conservation or a designated natural heritage area
  • Plant or wildlife habitat which is determined to be of local significance
  • Forest interior dwelling bird habitat
  • Colonial water bird nesting habitat
  • Habitat for the feeding, resting or grouping of wintering and migrating waterfowl species
  • Anadromous fish propagation waters
These areas were intensely developed prior to 1985. Most of the IDA is served by public water and sewer. There is little natural habitat in these areas; however, Habitat Protection Areas must always be protected.

10$ Rule
Development projects of more than 250 square feet in the IDA are regulated by the 10% Rule. The 10% Rule requires new construction or redevelopment to improve water quality by 10% from pre-development levels by using stormwater management or landscaping.

Landscaping in lieu of stormwater management must be done in permeable areas equal to, or greater in area than the increase of impervious surface. Plantings in lieu of stormwater management are credited at a rate of 1 tree per 100 square feet of new impervious surfaces and woody shrubs are credited at 50 square feet. These must be established and maintained in accordance with a plan approved by the Department of Planning and Zoning. If stormwater management or landscaping is not feasible, the owner may pay a fee in lieu of $1.20 per square foot of the new impervious surface. This money will then be used to fund projects that improve the water quality of the Chesapeake Bay.

These are areas that were developed in moderate to low intensities or were undeveloped in 1985. LDA and RCA may contain extensive plant and animal habitats. As stated above, Habitat Protection Areas are protected wherever they occur in the CBCA.

New development in the LDA and RCA may not degrade water quality, and must conserve existing areas of natural habitat. Wildlife corridors which provide continuity of wildlife and plant habitat must be shown on subdivision plans.

All lots designated LDA or RCA are subject to lot coverage limitations which may be either 15% or 25% of the total square footage of the lot or parcel. Please contact the Department of Planning and Zoning at 410-638-3103 for more detail with regard to specific lots.

Note: Development in LDA is permitted according to the underlying zoning density restrictions. Development in RCA may occur at a density of no more than 1 house per 20 acres.