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Garrett County, Maryland Seal
Garrett County Government
301.334.8970 | [email protected]

Development - Floodway


Floodways shall be preserved to carry the discharge of the 100-year flood. Floodways present increased risks to human life and property because of their relatively faster and deeper flowing waters. Fill shall not be permitted. New residential structures shall not be permitted. Other new development shall not be permitted in the floodway except where the lowest floor of the new structure is at or above the flood protection elevation (FPE) and the effect of the development on flood heights is fully offset by accompanying stream modification in accord with §151.072 of the Garrett County Floodplain Managment Ordinance and the development is approved by the MDE through the issuance of a water way construction permit and when necessary, the U.S. Army Corps of Engineers. Any development in the floodway which may result in an increase in water surface elevations or change to the floodway must be submitted to FEMA for a Conditional Letter of Map Revision, and Letter of Map Revision shall be obtained from FEMA following completion of the project. Hydrologic and hydraulic analyses based on existing floodway models and performed in accordance with standard engineering practices and certified by a registered professional engineer must be submitted. Failure to receive this letter shall be grounds for denial of the permit. An alternative analysis must be prepared for any development in the floodway before a permit may be issued. The provisions of §151.055 through §151.070 through §151.074 of the Garrett County Floodplain Mangement Ordinance, apply to floodways.

Alternative Analysis Requirement

Before a permit may be issued, an applicant shall submit an alternative analysis which demonstrates that:
  1. No reasonable alternatives exist outside the floodway;
  2. Encroachment in the floodway is the minimum necessary;
  3. The development will withstand the 100-year flood without significant damage; and
  4. The development will not increase downstream or upstream flooding or erosion.

Existing Structures

Existing structures in the floodway shall not be substantially improved (more than 50% of market value) or replaced unless the lowest floor of the structure is elevated at or above the flood protection elevation (FPE) and the effect of the proposed development or improvement on flood heights is fully offset by accompanying stream modifications. All proposals to offset the effects of building in the floodway by construction of stream modifications, shall be documented by an engineering study study prepared by a registered professional engineer which fully evaluates the effects of such construction and shall be submitted to MDE. The report shall use the Flood Insurance Study and the Flood Insurance Rate Maps as prepared by the Federal Emergency Management Agency and adopted herein as the basis of the analysis. The County shall not issue any permit for construction in the floodway until it has received written notice from the MDE that a waterway construction permit for the proposal has been approved.
The placement of any manufactured homes or buildings in the floodway shall be prohibited except where the manufactured home is replacing an existing manufactured home of equal dimensions, has a lowest floor which is 1 foot above the elevation of the 100-year flood, and has no effect on flood heights. Such replacement must be approved by the MDE through the issuance of a waterway construction permit.

Maintenance of Nature Channels

The natural watercourse shall be maintained for protection of aquatic resources. A variance is required for alteration of watercourses. Any variance issued must assure that the conditions for encroachment in the floodway are met, adverse impacts to aquatic resources are minimized, and the public good outweighs the adverse impacts. The provisions of §151.023 and §151.074 of the Garrett County Floodplain Managment Ordinance pertaining to altering a watercourse must be met.


Structures or fill which may impede, retard, or change the direction of the flow of flood waters, or any materials that may be carried downstream to cause damage shall not be placed in the floodway. Fences, except 2 wire fences, shall not be permitted in the floodway.

Call 301-334-1923 for more information relative to floodway development.