# Sec. 32-203. Definitions Codified through Bill No. CB-018-2026, adopted May 12, 2026, effective July 24, 2026. Source: Municode, Supplement 2026 Update 2. Editorial notes and legislative history omitted. ## Sec. 32-203. Definitions Prince George's County, Md., Code § 32-203 (2026) (a) The following terms shall have the meanings indicated: (1) Accessory Structure - A detached structure on the same parcel of property as the principal structure, the use of which is incidental to the principal structure. (Examples would be a shed or detached garage, etc.). For the purposes of these regulations, an accessory structure shall be used solely for parking of vehicles and limited storage. (2) Agreement to Submit an Elevations Certificate - A form on which the applicant for a permit to construct a building or structure, to construct certain horizontal additions, to place or replace a manufactured home, to substantially improve a building, structure, or manufactured home, agrees to have an Elevation Certificate prepared by a licensed professional engineer or licensed professional surveyor, as specified by the Floodplain Administrator or designee, and to submit the certificate: (A) Upon placement of the lowest floor and prior to further vertical construction; and (B) Prior to the final inspection and issuance of the Certificate of Occupancy. (3) Alteration of a Watercourse - For the purpose of these regulations, alteration of a watercourse includes, but is not limited to widening, deepening or relocating the channel, including excavation or filling of the channel. Alteration of a watercourse does not include construction of a road, bridge, culvert, dam, or in-stream pond unless the channel is proposed to be realigned or relocated as part of such construction. (4) Area of Shallow Flooding - A designated Zone AO on the Flood Insurance Rate Map with a 1-percent annual chance or greater of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident; such flooding is characterized by ponding or sheet flow. (5) Base Building - The building to which an addition is being added. This term is used in provisions relating to additions. (6) Base Flood (or 100-year Flood) - The flood that has a one percent (1%) chance of being equaled or exceeded in any given year; the base flood also is referred to as the 1-percent annual chance (100-year) flood. (7) Base Flood Elevation - The water surface elevation of the base flood in relation to the datum specified on the community's Flood Insurance Rate Map and any approved floodplain study. In areas of shallow flooding, the base flood elevation is the highest adjacent natural grade elevation plus the depth number specified in feet on the Flood Insurance Rate Map, or at least four (4) feet if the depth number is not specified. (8) Basement - Any area of a building having its floor subgrade (below ground level) on all sides. (9) Building Code(s) - Subtitle 4, the Prince George's County Building Code. (10) Coastal A Zone - An area within a special flood hazard area, landward of a coastal high hazard area (V Zone) or landward of a shoreline without a mapped coastal high hazard area, in which the principal source(s) of flooding are astronomical tides and storm surges, and in which, during base flood conditions, the potential exists for breaking waves with heights greater than or equal to 1.5 feet. The inland limit of the Coastal A Zone may be delineated on FIRMs as the Limit of Moderate Wave Action (LiMWA). (11) Coastal High Hazard Area - An area of special flood hazard extending from offshore to the inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms. Coastal high hazard areas also are referred to as "V Zones" and are designated on FIRMs as zones VE or V1-30. (12) Community - A political subdivision of the State of Maryland (county, city or town) that has authority to adopt and enforce floodplain management regulations within its jurisdictional boundaries. (13) County Floodplain or the Floodplain - Includes those areas within the County that will be inundated by the one percent annual chance base flood, as determined by FEMA or the County (see definition of "Flood or Flooding"). (14) Critical and Essential Facilities - Buildings and other structures that are intended to remain operational in the event of extreme environmental loading from flood, wind, snow or earthquakes. Critical and essential facilities typically include hospitals, fire stations, police stations, storage of critical records, facilities that handle or store hazardous materials, and similar facilities. (15) Declaration of Land Restriction (Nonconversion Agreement) - A form signed by the owner to agree not to convert or modify in any manner that is inconsistent with the terms of the permit and these regulations, certain enclosures below the lowest floor of elevated buildings and certain accessory structures. The form requires the owner to record it on the property deed to inform future owners of the restrictions. (16) Department - The Prince George's County Department of Permitting, Inspections, and Enforcement (DPIE). (17) Development - Any manmade change to improved or unimproved real estate including, but not limited to, any construction, reconstruction, modification, extension or expansion of buildings or other structures, placement of manufactured homes, placement of fill or concrete, construction of new or replacement infrastructure, dumping, mining, dredging, grading, paving, drilling operations, storage of materials, land excavation, land clearing, land improvement, landfill operation, or any combination thereof. (18) Director - The Director of the Prince George's County Department of Permitting, Inspections, and Enforcement (DPIE) or the Director's designee. (19) Discharge - A flow rate of stormwater runoff. For non-FEMA flood studies, discharge is based on ultimate land use conditions. (20) Elevation Certificate - FEMA form on which surveyed elevations and other data pertinent to a property and a building are identified and which shall be completed by a licensed professional land surveyor or a licensed professional engineer, as specified by the Floodplain Administrator. When used to document the height above grade of buildings in FEMA special flood hazard areas, for which base flood elevation data are not available, the Elevation Certificate shall be completed in accordance with the instructions issued by FEMA. The certificate verifies the as-built elevation of a structure using Mean Sea Level as established by the National Geodetic Vertical Datum (NGVD) of 1929, the North American Vertical Datum (NAVD) of 1988, and the WSSC Datum. An elevation certificate shall identify the datum of the site topography. (21) Enclosure Below the Lowest Floor - An unfinished or flood-resistant enclosure that is located below an elevated building, is surrounded by walls on all sides, and is usable solely for parking of vehicles, building access or storage, in an area other than a basement area, provided that such enclosure is built in accordance with the applicable design requirements specified in these regulations. Also see "Lowest Floor." (22) Existing Condition Floodplain - The 1-percent annual chance (100-year) floodplain conditions before the proposed development is started. For non-FEMA floodplain studies, this is based on ultimate development hydrology and existing channel conditions. (23) Federal Emergency Management Agency (FEMA) - The Federal agency with the overall responsibility for administering the National Flood Insurance Program (NFIP). (24) FEMA Floodplain - The flood hazard area as shown on FEMA maps, which is based on existing land use conditions. (25) FEMA Maps - The Flood Insurance Rate Maps (FIRM) and any subsequent amendments or revisions. (26) Flood (or Flooding) - A general and temporary condition of partial or complete inundation of normally dry land areas from the overflow of inland or tidal waters, or the rapid and unusual accumulation of runoff of surface water from any source. (27) Flood Damage-Resistant Materials - Any construction material that is capable of withstanding direct and prolonged contact with floodwaters without sustaining any damage that requires more than cosmetic repair. (28) Flood Insurance Rate Map (FIRM) - An official map on which the Federal Emergency Management Agency delineated the minimum special flood hazard areas to indicate the magnitude and nature of flood hazards, to designate applicable flood zones, and to delineate floodways, if applicable. FIRMs that have been prepared in digital format or converted to digital format are referred to as Digital FIRMs (DFIRM). (29) Flood Insurance Study (FIS) - The official report in which the Federal Emergency Management Agency has provided engineering methodology to compute flood profiles, floodway information, and the water surface elevations. (30) Flood Opening - A flood opening (non-engineered) is an opening that is used to meet the prescriptive requirement of one (1) square inch of net open area for every square foot of enclosed area. An engineered flood opening is an opening that is designed and certified by a licensed professional engineer or licensed architect as meeting certain performance characteristics, including providing automatic entry and exit of floodwaters; this certification requirement may be satisfied by an individual certification for a specific structure. (31) Floodplain means in general: (A) Relatively flat or low land area adjoining a river, stream or other watercourse which is subject to partial or complete inundation; (B) Area subject to the unusual and rapid accumulation or runoff of surface waters from any source; or (C) Area subject to tidal surges or extreme tides. (32) Floodplain Buffer - An area extending beyond and paralleling the County floodplain to maintain the stability of steep slopes, to preserve the environmental integrity of stream or wetland habitats associated with a floodplain, and to otherwise protect and maintain the public safety. (33) Flood proofing (or Flood Proofed) - Any combination of structural and nonstructural additions, changes or adjustments of properties and structures that reduce or eliminate flood damage to lands, water and sanitary facilities, structures, and contents of buildings, such that the buildings or structures are watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. (34) Flood proofing Certificate - A form supplied by the Federal Emergency Management Agency that is to be completed, signed and sealed by a licensed professional engineer or licensed architect to certify that the design of flood proofing and proposed methods of construction are in accordance with the applicable requirements to the Flood Protection Elevation. (35) Flood Protection Elevation (FPE) - The base flood elevation plus freeboard. Two (2) feet of freeboard are required for FEMA purposes only. For non-FEMA studies, one (1) to two (2) feet of freeboard are required, based on the specific watershed, as described in the Prince George's County, Maryland, Stormwater Management Design Manual (the "Manual"). (36) Floodway - The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to pass the base flood discharge such that the cumulative increase in the water surface elevation of the base flood discharge is no more than one (1) foot. When shown on a FIRM, the floodway is referred to as the "designated floodway." (37) Floodway Fringe - That portion of the floodplain outside the floodway. (38) Floodway Map - A map which depicts floodways and special flood hazard areas to be regulated. (39) Floodway Surcharge - The increase in the one percent annual chance 100-year flood elevation due to an encroachment within the floodplain. (40) Flood Zone - A designation for areas that are shown on Flood Insurance Rate Maps: (A) Zone A: Special flood hazard areas subject to inundation by the 1-percent annual chance (100-year) flood; base flood elevations are not determined. (B) Zone AE and Zone A1-30: Special flood hazard areas subject to inundation by the 1-percent annual chance (100-year) flood; base flood elevations are determined; floodways may or may not be determined. In areas subject to tidal flooding, the Limit of Moderate Wave Action may or may not be delineated. (C) Zone AH and Zone AO: Areas of shallow flooding, with flood depths of one (1) to three (3) feet (usually areas of ponding or sheet flow on sloping terrain), with or without BFEs or designated flood depths. (D) Zone B and Zone X (shaded): Areas subject to inundation by the 0.2-percent annual chance (500-year) flood; areas subject to the 1-percent annual chance (100-year) flood with average depths of less than one (1) foot or with contributing drainage area less than one (1) square mile; and areas protected from the base flood by levees. (E) Zone C and Zone X (unshaded): Areas outside of Zones designated A, AE, A1-30, AO, VE, V1-30, B, and X (shaded). (F) Zone VE and Zone V1-30: Special flood hazard areas subject to inundation by the 1-percent annual chance (100-year) flood and subject to high velocity wave action (also see coastal high hazard area). (41) Freeboard - A factor of safety that compensates for uncertain circumstances that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, obstructed bridge openings, debris and ice jams, climate change, and the hydrologic effect of urbanization in a watershed. (42) Free-of-Obstruction - A term that describes open foundations (pilings, columns, or piers) without attached elements or foundation components that would obstruct the free passage of floodwaters and waves beneath structures that are elevated on such foundations. (43) Functionally Dependent Use - A use which cannot perform its intended purpose unless it is located or carried out in close proximity to water; the term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, but does not include long-term storage or related manufacturing facilities. (44) Geographic Information System (GIS) Based Floodplain Model - The hydrology and hydraulic models developed by the Department of the Environment (DoE) using GIS technologies and databases to determine peak discharges and flood elevations. (45) Highest Adjacent Grade - The highest natural elevation of the ground surface, prior to construction, next to the proposed foundation of a structure. (46) Historic Structure - Any structure that is: (A) Individually listed in the National Register of Historic Places (a listing maintained by the U.S. Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listings on the National Register; (B) Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; (C) Individually listed on the Maryland Register of Historic Places; or (D) Individually listed on the inventory of historic places maintained by Prince George's County whose historic preservation program has been certified by the Maryland Historical Trust or the Secretary of the Interior. (47) Hydrologic and Hydraulic Engineering Analyses - Analyses performed by a licensed professional engineer, in accordance with standard engineering practices that are accepted by Prince George's County, the Maryland Department of the Environment (Nontidal Wetlands & Waterways) and FEMA, used to determine the base flood, other frequency floods, flood elevations, floodway information and boundaries, and flood profiles. (48) Letter of Map Change (LOMC) - A Letter of Map Change is an official FEMA determination, by letter, that amends or revises an effective Flood Insurance Rate Map or Flood Insurance Study. Letters of Map Change include: (A) Letter of Map Amendment (LOMA): An amendment based on technical data showing that a property was incorrectly included in a designated special flood hazard area. A LOMA amends the current effective Flood Insurance Rate Map and establishes that a specific property or structure is not located in a special flood hazard area. (B) Letter of Map Revision (LOMR): A revision based on technical data that may show changes to flood zones, flood elevations, floodplain and floodway delineations, and planimetric features. A Letter of Map Revision Based on Fill (LOMR-F), is a determination that a structure or parcel of land has been elevated by fill above the base flood elevation and is, therefore, no longer exposed to flooding associated with the base flood. In order to qualify for this determination, the fill must have been permitted and placed in accordance with the community's floodplain management regulations. (C) Conditional Letter of Map Revision (CLOMR): A formal review and comment as to whether a proposed flood protection project or other proposed project complies with the minimum NFIP requirements for such projects with respect to delineation of special flood hazard areas. A Conditional Letter of Map Revision Based on Fill (CLOMR-F) is a determination that a parcel of land or proposed structure that will be elevated by fill would not be inundated by the base flood if fill is placed on the parcel as proposed or the structure is built as proposed. A CLOMR does not revise the effective Flood Insurance Rate Map or Flood Insurance Study. Once the CLOMR is approved, a follow-up LOMR is submitted. Upon submission and approval of certified as-built documentation, a Letter of Map Revision may be issued by FEMA, to revise the effective FIRM. (49) Licensed - As used in these regulations, licensed refers to professionals who are authorized, and in good standing, to practice in the State of Maryland by issuance of licenses by the Maryland Board of Architects, Maryland Board of Professional Engineers, Maryland Board of Professional Land Surveyors, and the Maryland Real Estate Appraisers and Home Inspectors Commission. (50) Limit of Moderate Wave Action (LiMWA) - Inland limit of the area affected by waves greater than one and one-half (1.5) feet during the base flood. Base flood conditions between the VE Zone and the LiMWA will be similar to, but less severe than those in the VE Zone. (51) Lowest Floor - The lowest floor of the lowest enclosed area (including basement) of a building or structure; the floor of an enclosure below the lowest floor is not the lowest floor provided the enclosure is constructed in accordance with these regulations. The lowest floor of a manufactured home is the bottom of the lowest horizontal supporting member (longitudinal chassis frame beam). (52) Manufactured Home or Building (for FEMA purposes only) - A structure transportable in one or more sections built on a permanent chassis and designed for use with or without a permanent foundation when connected to required utilities. For floodplain management purposes, the term "manufactured home or building" also includes park trailers, travel trailers, and other similar vehicles placed on a site for more than one hundred eighty (180) consecutive days. (53) Market Value - The price at which a property will change hands between a willing buyer and a willing seller, neither party being under compulsion to buy or sell and both having reasonable knowledge of relevant facts. For the purposes of these regulations, the market value of a building is determined by a licensed real estate appraiser or the most recent, full phased-in assessment value of the building (improvement) determined by the Maryland Department of Assessments and Taxation. (54) Maryland Department of the Environment (MDE) - A principal department of the State of Maryland that is charged with, among other responsibilities, the coordination of the National Flood Insurance Program in Maryland (NFIP State Coordinator) and the administration of regulatory programs for development and construction that occur within the waters of the State, including nontidal wetlands, nontidal waters and floodplains, and State and private tidal wetlands (Tidal Wetlands). Unless otherwise specified, "MDE" refers to the Department's Wetlands and Waterways Program. (55) Mixed-Use Structure - Any structure that is used or intended for use for a mixture of nonresidential and residential uses in the same structure. (56) National Flood Insurance Program (NFIP) - The program authorized by the U.S. Congress in 42 U.S.C. §§ 4001—4129. The NFIP makes flood insurance coverage available in communities that agree to adopt and enforce minimum regulatory requirements for development in areas prone to flooding (see definition of "Special Flood Hazard Area"). (57) National Geodetic Vertical Datum (NGVD) - The National Geodetic Vertical Datum of 1929 elevation reference points set by the national Geodetic Survey based on Mean Sea Level. (58) New Construction - Structures, including additions and improvements, and the placement of manufactured homes, for which the start of construction commenced on or after August 4, 1972, the initial effective date of the Prince George's County Flood Insurance Rate Map (FIRM), including any subsequent improvements, alterations, modifications, and additions to such structures. (59) NFIP State Coordinator - See Maryland Department of the Environment (MDE). (60) North American Vertical Datum (NAVD) - The North American Vertical Datum of 1988 is the vertical control datum established for vertical control surveying in the United States of America based upon the General Adjustment of the North American Datum of 1988. (61) Non-tidal Waters of the State - See "Waters of the State." As used in these regulations, "non-tidal waters of the State" refers to any stream or body of water within the State that is subject to State regulation, including the "100-year frequency floodplain of free-flowing waters." COMAR 26.17.04.01 states that "the landward boundaries of any tidal waters shall be deemed coterminous with the wetlands boundary maps adopted pursuant to Environment Article, § 16-301, Annotated Code of Maryland." Therefore, the boundary between the tidal and non-tidal waters of the State is the tidal wetlands boundary. (62) Permanent Structure (for FEMA purposes only) - any structure occupying a site for more than one hundred eighty (180) consecutive days per year. (63) Proposed Condition Floodplain - The 1-percent annual chance (100-year) floodplain conditions after the proposed development is completed. Proposed condition floodplain reflects proposed changes within the floodplain area, including: grading, road crossings, culverts, dams, embankments, bridges, structures and other modifications. For non-FEMA floodplain studies, this is based on ultimate development hydrology and proposed channel conditions. (64) Recreational Vehicle (for FEMA purposes only) - A vehicle built on a single chassis that is four hundred (400) square feet or less when measured at the largest horizontal projection, designed to be self-propelled or permanently towable by a light duty truck, and designed primarily not for use a permanent dwelling, but as temporary living quarters for recreational, traveling, camping, or seasonal use. (65) Registered Engineer, Registered Land Surveyor, or Registered Architect - a professional engineer, land surveyor, or architect licensed to practice said profession and in good standing in the State of Maryland. (66) Riparian Buffer - A riparian buffer is a vegetated area (a "buffer strip") near a stream, usually forested, which helps shade and partially protect a stream from the impact of adjacent land uses. A riparian buffer provides an environmental benefit by increasing water quality in associated streams, rivers, and lakes. (67) Special Flood Hazard Area (SFHA) - The land in the floodplain subject to a one-percent or greater chance of flooding in any given year. Special flood hazard areas are designated by the Federal Emergency Management Agency in Flood Insurance Studies and on Flood Insurance Rate Maps as Zones A, AE, AH, AO, A1-30, and Zones VE and V1-30 and A99. The term includes areas shown on other flood maps and that are identified in Section 32-204(a) of the County Code. (68) Start of Construction (for FEMA purposes only) - The date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement or other improvement occurs within one hundred eighty (180) days of the permit date. The actual start of construction means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, installation of piles, the construction of columns, or any work beyond the stage of excavation, or placement of a manufactured home on a foundation. Permanent construction, as used in this definition, does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory structures, such as garages or sheds not occupied as dwelling units or not as part of the main structure. For substantial improvements, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building. (69) Structure - That which is built or constructed; specifically, a walled and roofed building, including, but not limited to, a gas or liquid storage tank that is principally above ground, a building foundation, or platform that is affixed to a permanent site or location as well as a manufactured home. (70) Substantial Damage - Damage of any origin sustained by a building or structure whereby the cost of restoring the building or structure to its condition before damage would equal or exceeds fifty percent (50%) of the market value of the building or structure before the damage occurred. (71) Substantial Improvement (for FEMA purposes only) - Any reconstruction, rehabilitation, addition, or other improvement of a building or structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the building or structure (less land value). The term includes structures which have incurred substantial damage, regardless of the actual repair work performed. The term does not, however, include either: (A) Any project for improvement of a building or structure to correct existing violations of State or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official prior to submission of an application for a permit and which are the minimum necessary to assure safe living conditions; or (B) Any alteration of a historic structure, provided that the alteration will not preclude the structures' continued designation as a historic structure. (72) Temporary Structure (for FEMA purposes only) - Any structure completely removed within one hundred eighty (180) days from issuance of the permit. (73) Use and Occupancy Permit - The official approval from the Department of Permitting, Inspections and Enforcement (DPIE) indicating that the structure has been built consistent with approved plans and may be legally inhabited or used for the intended purpose. (74) Violation (for FEMA purposes only) - Any construction or development in a special flood hazard area that is being performed without an issued permit. The failure of a building, structure, or other development for which a permit is issued to be fully compliant with these regulations and the conditions of the issued permit. A building, structure, or other development without the required design certifications, the Elevation Certificate, or other evidence of compliance required is presumed to be a violation until such time as the required documentation is provided. (75) Waiver (or Variance) - A grant of relief from the strict application of one or more requirements of this Floodplain Ordinance. (76) Watercourse - The channel, including channel banks and bed, of nontidal waters of the State. (77) Waters of the State - Waters of the State include: (A) Both surface and underground waters within the boundaries of the State subject to its jurisdiction; (B) That portion of the Atlantic Ocean within the boundaries of the State; (C) The Chesapeake Bay and its tributaries; (D) All ponds, lakes, rivers, streams, public ditches, tax ditches, and public systems within the State, other than those designed and used to collect, convey, or dispose of sanitary sewage; and (E) The floodplain of free-flowing waters determined by MDE on the basis of the 1-percent annual chance (100-year) flood frequency. (78) Wetland - An area that is: (A) Inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs and similar areas; (B) Considered "private wetland" or "State wetland" pursuant to Title 9, Wetlands and Riparian Rights, Natural Resources Article, Annotated Code of Maryland; or (C) Defined as wetland under the procedures described in the "Federal Interagency Committee for Wetland Delineation" most updated version and as amended from time to time.