
Private vs. State Tidal Wetlands
Annotated Code of Maryland, Environment Article, Title 16. Wetlands and Riparian Rights (§16-10l) defines:
State Wetlands — “State wetlands” means any land under the navigable waters of the State below the mean high tide, affected by the regular rise and fall of the tide. Wetlands of this category which have been transferred by the State by valid grant, lease, patent or grant confirmed by Article 5 of the Maryland Declarations of Rights shall be considered “private wetland” to the extent of the interest transferred.
Private Wetlands — (1) “Private wetlands” means any land not considered “State wetland” bordering on or lying beneath tidal waters, which is subject to regular or period tidal action and supports aquatic growth. (2) “Private wetlands” includes wetlands, transferred by the State by a valid grant, lease, patent or grant confirmed by Article 5 of the Maryland Declaration of Rights, to the extent of the interest transferred.
In general terms and as shown in the diagram below, State tidal wetlands (may be referred to as low marsh) are those areas subject to the daily ebb and flow of the tide. Private tidal wetlands (may be referred to as high marsh) are those areas subject to tidal inundation on a less frequent basis, sometimes monthly and sometimes annually (e.g., during Spring tides). There is a common misconception that all vegetated wetlands are private and only open water is State. Please note that State tidal wetlands include some areas of wetland vegetation.

Making the Determination
Acceptable Methods (may vary from site to site):
- Vegetative analyses of the wetlands using accepted survey methods, transects, etc.
- Where vegetation is ambiguous, established NOAA benchmarks and tide data (if the tide station is close enough) can determine the elevation of mean high tide.
- If tidal information is unavailable, an on-site tide station, along with NOAA benchmarks and vegetative analyses.
Needed Documentation
A professional should document how the determination was made, either as part of the required environmental report or separately. It should include a description of the survey methods, a description of findings and conclusions, benchmark and/or tide station data and a graphical depiction of the results. The State/private boundary should be flagged in the field and then surveyed. A Jurisdictional Determination from the Army Corps of Engineers does not distinguish between State and private wetlands and may not be sufficient to document ownership.
If a property owner is claiming ownership via a valid land patent or King’s grant, documentation from the Commissioner of Land Patents must be provided.
Why Does It Matter?
Private Wetlands - Can be included in gross site acreage for Critical Area calculation purposes. State Wetlands - Are not privately owned, cannot be used for Critical Area calculation purposes.

Parcel 116 - Deed and/or tax records indicate a total acreage of 165 acres. The property has a Critical Area designation of RCA. There is no valid land patent or King’s grant for the property. The proposed subdivision plat for eight (8) lots at one dwelling unit per 20 acres shows a boundary survey to the center of Pikes Creek. A total of 68 acres are shown as “tidal wetlands” without any additional documentation.
A determination as to the ownership of the tidal wetlands must be made in order to:
- Calculate allowable density
- Determine permitted impervious surface coverage
- Calculate afforestation or reforestation requirements
In the example above, Critical Area issues are evident. If the 68 acres of tidal wetlands are below mean high water (MHW) and are determined to be State wetlands, allowable density on the remaining 97 acres of the property is four (4) dwelling units. The impervious coverage allowance and afforestation requirements would also be based on 97 acres. If all 68 acres of tidal wetlands are determined to be above MHW, allowable density would be the eight dwelling units proposed. (Natural Resources Article, §8-1808.1, “In calculating the 1-in-20 acre density ... a local jurisdiction may permit the area of any private wetlands on the property to be included ... the density of development on the upland portion of the parcel may not exceed 1 dwelling unit per 8 acres.”) Allowable impervious coverage and afforestation requirements would be based on the entire 165 acres. It is likely that there would be some State wetlands and some private, with the allowable density somewhere between 4 and 8 units.
Guidance Publications
- Bay Smart Guide
- Overview of House Bill 1253 - 2008 Legislation
(Adobe Acrobat file 220KB) - A Guide to the Conservation of Forest Interior Dwelling Birds in the Chesapeake Bay Critical Area
(Adobe Acrobat file 270KB) - Critical Area 10% Rule Guidance Manual
- Private vs. State Tidal Wetlands
- Forest Mitigation
- Public Walkways
- Living Shorelines
- Backyard Makeover
- Golf Courses in the RCA - Final
- Native Plants for Wildlife Habitat and Conservation Landscaping - Chesapeake Bay Watershed - U.S. Fish & Wildlife Service
- Local Government Assistance Guide - Critical Area Buffer
- Local Government Assistance Guide - Lot Coverage
NEW PUBLICATION!
This new publication was developed to assist homeowners with planting and maintaining shoreline Buffers. It includes lots of information about the importance of the Critical Area Buffer and includes Buffer Management Plans that can be used to satisfy Buffer planting requirements for new construction on waterfront lots.
Meetings and Hearings
For general questions ...
... or information about the Critical Area Program or questions relating to State oversight of local programs, e-mail Mary Owens or call 410-260-3480.





