Environmental Protection and Sustainability
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Chesapeake Bay Critical Area

Mapping Update Questions

What does the letter I received mean to me?
The letter means that the location of the Critical Area boundary line is being changed on your property, and that at least a portion of your property will be subject to the state-mandated Chesapeake and Atlantic Coastal Bays Critical Area law.

What is the County going to do on my property?
The County is not making any physical changes to your property. The Critical Area boundary is a line on map, just like a zoning line.

Will the map change impact my flood insurance?
The mapping change will have no effect on flood insurance.

Will the map change affect the value of my property?
The mapping change will not change your property value.

Will the map change increase my property taxes?
The mapping change will not change your taxes.

Are my existing structures grandfathered?
Yes, the existing structures and other items on your property making up the lot coverage (formerly impervious surfaces) are grandfathered, and do not have to be removed.

Why is my property now considered wetlands?
The County has not designated your property wetlands. The mapping change means that your property is within or partially within 1,000 feet from tidal wetlands or open water.

Do I need to do anything now as a result of the map change?
The map change does not require that you do anything right now. However, if you apply for a building permit in the future you will be subject to the state-mandated Chesapeake and Atlantic Coastal Bays Critical Area law for the portion of your property that will be in the Critical Area. We encourage you to look at the maps online so you know where the Critical Area boundary will be on your property. We also encourage you to call us at 410-887-3980 if you have any questions.

Mapping Update Project

The Critical Area maps have been updated as part of a comprehensive mapping effort required by legislative changes to Maryland's Critical Area Program. The maps are the result of the collaborative efforts of the Critical Area Commission, the Department of Natural Resources, the Eastern Shore Regional GIS Cooperative, and the Baltimore County Department of Environmental Protection and Sustainability.

Interested parties may view the updated maps from the Critical Area Commission. Questions or comments about the mapping update project may be directed to the Environmental Impact Review Section by calling 410-887-3980 or by emailing eps@baltimorecountymd.gov.


In 1984, the Maryland General Assembly passed the Chesapeake Bay Critical Area Law because of growing concern about the decline of water quality and the natural resources of the Chesapeake Bay. Land use immediately surrounding the Chesapeake Bay and its tributaries has the greatest potential to affect water quality and habitat. A geographical area around the Chesapeake Bay's tidal waters and tributaries have been designated as "Critical Area" by the General Assembly and shown on the State Tidal Wetland maps. The Baltimore County Chesapeake Bay Critical Area Program was adopted in 1988.

The Program places all lands in the Critical Area into one of three land use categories, which are:

  1. Intensely Developed Areas (IDA)
    IDAs are residential, commercial, institutional, or industrial and developed land uses are predominate. Relatively little natural habitat occurs. Pollutant loadings must be reduced by 10 percent and Habitat Protection Areas must be protected. A minimum 100-foot buffer is required.
  2. Limited Development Areas (LDA)
    LDAs have low or moderate intensity uses and co-exist with natural plant and animal habitats. Runoff has not been substantially altered or impaired.
  3. Resource Conservation Areas (RCA)
    Natural resource areas such as habitats, wetlands and forests and resource-oriented activities such as farming and fishing predominate in RCAs.

Growth Allocation allows RCA to be converted to LDA or IDA, or LDA to be converted to IDA.

Environmental Impact Review Forms


Read regulations administered by Environmental Impact Review.

View fact sheets about the Chesapeake Bay Critical Area:

The Critical Area Commission offers information on the state's Critical Area Program, regulations, Citizen's Guide, riparian habitat and more.

Looking for an aerial view of you property? Go to MyNeighborhood to get an up-to-date view of your property.

Contact Information

Environmental Impact Review
Phone: 410-887-3980
Fax: 410-887-4804
Email: eps@baltimorecountymd.gov

Revised August 7, 2014

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