Article III. Floodplain District Requirements.
Montgomery County, Md., Code § 19-36 (2026)
Sec. 19-36. Definitions.LinkCopy Citation
In this Article and any regulations issued under it, these words and phrases have the following meanings:
Accessory/appurtenant structure: A structure that is located on the same lot as a principal structure and has a use that is incidental to the use of the principal structure.
Basement: Any area of a building having its floor below ground level on all sides. Any other bottom floor of a building is a first floor.
Certificate of Occupancy: A form issued by the Department certifying that a structure has been built consistent with an approved floodplain district permit plan and may be legally inhabited for the intended purpose.
Department: The Department of Permitting Services.
Developer: A person for whose benefit any activity regulated by this article is started or carried on. An individual who builds a single-family house for the individual's own occupancy is not a developer.
Development: Any man-made change to improved or unimproved real estate, including any building or other structure, dredging, fill, grading, paving, clearing, excavation, dumping, extraction, or storage of equipment or materials. Development includes subdivision of land.
Director: The Director of the Department of Permitting Services, or a duly authorized agent.
Elevation certificate: A form prepared and distributed by the Federal Emergency Management Agency using Mean Sea Level as established by the National Geodetic Vertical Datum of 1929 and verifying the elevation at which a floor is constructed.
Flood: A temporary inundation of normally dry land areas.
Floodplain:
(a)
A relatively flat or low land area adjoining a river, stream, pond, stormwater management structure, or watercourse subject to partial or complete inundation; or
(b)
An area subject to unusual and rapid accumulation or runoff of surface water as a result of an upstream dam failure.
Floodplain district: Any area specified in Executive regulations that is subject to inundation in a 100-year storm. This includes any waterway with a drainage area of 30 acres or larger.
Floodplain district permit: A permit issued by the Department under this article authorizing land-disturbing and construction activities.
Floodplain district permit plan: A set of representational drawings or other documents submitted by an applicant to obtain a floodplain district permit that contains the information and specifications the Department requires to minimize the safety hazards of or the negative hydraulic and environmental impacts associated with development in or near a floodplain.
Floodproofing: Any combination of structural and non-structural additions or changes to a property or structure which reduce or eliminate flood damage.
Floodway: The channel and adjacent land area required to discharge the waters of the 100-year flood of a watercourse without increasing the water surface elevations.
Flood Fringe: That portion of the floodplain outside the floodway.
Historical Structure: A structure listed individually on the National Register of Historic Places, the Maryland Inventory of Historic Properties, a local inventory of historic places certified by the Maryland Historic Trust or the Secretary of the Interior, or preliminarily determined as meeting the requirements for such listing by the Maryland Historic Trust or the Secretary of the Interior, or determined as contributing to the historic significance of a historic district registered with the Secretary of the Interior.
Land disturbing activity:
(a)
any earth movement or land change which may result in soil erosion from water or wind;
(b)
the movement of sediments into state waters or onto land, including tilling, clearing, grading, excavating, stripping, filling, and related activities; or
(c)
covering land with an impermeable material.
Lowest floor: The lowest floor of the lowest enclosed area of a building, including a basement. An unfinished or flood-resistant enclosure, usable only for parking motor vehicles, building access, or storage, is not a building's lowest floor if the enclosure does not violate the applicable non-elevation design requirements of the National Flood Insurance Program.
Manufactured home: A structure that is:
(a)
transportable in one or more sections;
(b)
built on a permanent chassis; and
(c)
designed for use with or without a permanent foundation connected to the required utilities.
Manufactured home also includes a park trailer, travel trailer, or similar vehicle, when placed on a site for more than 180 consecutive days.
Manufactured home park: A parcel or contiguous parcels of land divided into two or more manufactured home lots for rent or sale.
New construction: Any structure for which construction began on or after the date of entry into the Regular Program or the date this Article took effect, whichever occurred first.
100-year flood: A flood that has a one percent chance of being equalled or exceeded in a given year. Unless otherwise stated, this calculation is based on the contributing watershed being completely under existing zoning.
Permanent construction: Any structure built or placed on a site for more than 180 consecutive days.
Permittee: Any person who receives a permit under this article.
Person: Any individual, corporation, partnership, joint venture, firm, unincorporated association, municipal, county or state agency, or any combination.
Principally above ground: Any structure with at least 51 percent of the actual cash value of the structure, not including the land value, above ground.
Recreational Vehicle: A vehicle built on a single chassis which is 400 square feet or less at the longest horizontal projection, self propelled or towable, and designed primarily for temporary living while traveling or camping.
Start of construction: The earlier of:
(a)
The date the building permit was issued, if construction, repair, reconstruction, placement, substantial improvement, or other improvement starts within 180 days after the permit is issued; or
(b)
The actual start of construction, which means either:
(1)
the first placement or permanent construction of a structure on a site, such as the pouring of a slab or footings; or
(2)
any work beyond the excavation stage.
Structure: A walled or roofed building that is principally above ground and affixed to a permanent site or location. Structure includes a utility shed, barn, gas or liquid storage tank, building foundation, platform, deck, swimming pool, bulkhead, or greenhouse.
Subdivision: The division or redivision of any lot, tract, or parcel of land by any means into two or more lots, tracts, parcels, or other divisions of land. Subdivision includes a change in existing lot lines for the immediate or future purpose of lease, transfer of ownership, building, or development.
Substantial Damage: Damage of any origin sustained by a structure if the cost of restoring the structure to its previous condition is at least 50% of the market value of the structure before the damage occurred.
Substantial improvement: Any repair, reconstruction, or improvement of a structure, if the total cumulative cost equals or exceeds 50 percent of the market value of the structure either:
(a)
Before the improvement or repair is started; or
(b)
Before the damage occurred, if the structure has been damaged and is being restored.
Substantial improvement occurs when the first alteration of any wall, ceiling, floor, or other structural part of a building begins, whether or not that alteration affects the external dimensions of the structure.
Substantial improvement does not include:
(a)
Any improvements of a structure to comply with State or local health, sanitary, or safety codes which is necessary to assure safe living conditions; or
(b)
Any alteration of a structure listed on the National Register of Historic Places or the State Inventory of Historic Places.
Temporary development: Any structure or construction
(a)
used in construction work, such as a construction shed, seat, canopy, tent or fence; or
(b)
for a temporary purpose, such as a reviewing stand, fair, carnival or flea market, which is completely removed after 180 days or less.
Watercourse: Any natural or artificial waterway including a stream, river, creek, ditch, channel, canal, conduit, culvert, drain, waterway, gully, ravine, or wash, in which water flows either continuously or intermittently.
Wetland means any land which is:
(1)
considered private wetland or State wetland under Title 16 of the Environment Article of the Maryland Code; or
(2)
defined as a wetland under the procedures described in the most recent Federal manual for Identifying and Delineating a Jurisdictional Wetland.
Montgomery County, Md., Code § 19-37 (2026)
Sec. 19-37. When a floodplain district permit is required.LinkCopy Citation
(a)
A person must not engage in any land-disturbing activity within the floodplain district or within 25 feet of any boundary of the district unless the Department issues a floodplain district permit, except as provided in this section.
(b)
A floodplain district permit is not required for:
(1)
Any minor land-disturbing activity that:
(A)
Disturbs less than 5000 square feet of ground surface area;
(B)
Is promptly stabilized to prevent erosion and sedimentation; and
(C)
Does not substantially block or impede the flow of water or change the cross-section of the floodplain.
(2)
(A)
Any accepted agricultural land management practice, except that construction of agricultural structures requires a floodplain district permit; or
(B)
Any nursery operation, such as the removal or transplanting of cultivated sod, shrubs, and trees.
(3)
Any federal or state project exempted under State or Federal law if the proposed work is performed on State or Federally-owned land.
(c)
A person may engage in land-disturbing activity in the floodplain district or within 25 feet of any boundary of the district before a permit is issued if:
(1)
the activity is required to prevent or reduce an imminent and serious threat to life, health, or property, or to maintain or repair electricity, gas, water, or telephone service in an emergency;
(2)
the Director is notified, and proper sediment and erosion controls are installed, within 24 hours after the activity begins; and
(3)
an appropriate permit application is filed within 72 hours if the activity is not complete by that time.
The Director at any time may order any work done before a permit is issued to be modified as necessary to comply with this Article.
Montgomery County, Md., Code § 19-38 (2026)
Sec. 19-38. Application for permit.LinkCopy Citation
(a)
To obtain a floodplain district permit, an applicant must file an application in writing on a form furnished by the Department. The owner of the property where the land-disturbing activity is to be performed, or the owner's authorized agent, must sign the application.
(b)
A permit must be issued only in the name of the current property owner.
(c)
A separate permit must be issued for each non-contiguous site.
(d)
A permit may be transferred to a later owner, if the later owner files an application form and pays a transfer fee and the Director approves the transfer.
(e)
An application for a permit must be accompanied by:
(1)
An erosion and sediment control plan approved by the Department, where required by law; and
(2)
The permit fee.
(f)
Plans must be prepared and certified by:
(1)
A registered professional engineer, registered land surveyor, or architect; or
(2)
Another person approved by the Department.
(g)
Each floodplain district permit plan must comply with this article and applicable regulations.
Montgomery County, Md., Code § 19-39 (2026)
Sec. 19-39. Modification of plans.LinkCopy Citation
(a)
Any major modification of an approved plan must be submitted to the Department and may be approved or disapproved in the same manner as the original plan.
(b)
In an emergency situation, the Director may require the installation of interim flood protection measures to protect stream channels, other property, or the public from damage or danger. Any required measure must remain in effect until adequate modifications to an approved plan are approved and implemented.
(c)
The Department's field representative may authorize minor field modifications that are consistent with this article and applicable regulations.
Montgomery County, Md., Code § 19-40 (2026)
Sec. 19-40. Permit conditions.LinkCopy Citation
(a)
In granting a floodplain district permit, the Director may attach conditions that the Director finds:
(1)
Are reasonably necessary to prevent undue risk to public or private property; or
(2)
Will prevent the operation from being conducted in a manner hazardous to life or property.
(b)
Those conditions may include:
(1)
Erecting or installing walls, drains, dams, plantings, erosion and sediment control measures or devices;
(2)
Furnishing necessary easements; or
(3)
A specified method of performing the work.
(c)
Each condition must be identified on the approved floodplain district permit plan.
(d)
The approved plan is a condition of the permit.
(e)
A person must not violate any permit condition.
Montgomery County, Md., Code § 19-41 (2026)
Sec. 19-41. Permit expiration and renewal.LinkCopy Citation
Any permit issued under this article expires one year after the date of issuance. The Director may renew a permit for up to one additional year.
Montgomery County, Md., Code § 19-42 (2026)
Sec. 19-42. Inspection.LinkCopy Citation
(a)
The Department may enter any property subject to this article to inspect the property and enforce this article.
(b)
Any activity in conjunction with a permit must not proceed until the Department has issued the permit. All work must be performed in accordance with the approved plan and permit.
(c)
The permittee must notify the Department 48 hours before starting any activity in conjunction with a permit. The permittee or its representative must attend a pre-construction meeting with the Department unless the Department waives the meeting.
(d)
The permittee must keep a copy of the approved floodplain district permit plan and the permit available on site for inspection by the Department.
(e)
The Director must inspect each site that has a floodplain district permit plan to ensure compliance with the approved plan and all permit requirements.
(f)
If the permittee fails to comply with any requirement under this article, the Director must inspect the work and notify the permittee in writing. The notice must state:
(1)
The nature of the violation;
(2)
Any practice or plan deficiencies;
(3)
Any required corrective action; and
(4)
A reasonable time for compliance.
(g)
The permittee must promptly correct any portion of the work that does not comply.
(h)
The Department may make additional inspections as necessary, and may waive any inspection except the final inspection under section 19-43.
(i)
The Department must maintain a record of each inspection, including the date, location or project identification, whether the approved plan and permit conditions have been complied with and, if a violation exists, the enforcement action taken.
Montgomery County, Md., Code § 19-43 (2026)
Sec. 19-43. Permit revocation or suspension; stop work order.LinkCopy Citation
(a)
The Director may revoke or suspend any permit issued under this article, after the Department serves written notice on the permittee, for:
(1)
Violation of the approved plan or any other condition of thepermit;
(2)
Violation of any applicable law or regulation relating to the work;
(3)
The existence of any hazard or danger to human life or the property of others; or
(4)
Failure of the approved plan to achieve required objectives because of site characteristics or conditions.
(b)
In addition to the authority to revoke or suspend a permit under subsection (a), the Director may order that all construction activity in conjunction with a permit must stop immediately if:
(1)
Any construction activity violates a condition or requirement of a County permit, application, or approved plan, or this article or applicable regulations;
(2)
The Department delivers a written warning to the permittee or its representative that lists corrective measures required and the time by which the corrections must be made; and
(3)
The permittee does not make all corrections within the specified time.
(c)
The Department must provide a report to the permittee or its representative when a stop work order is issued. The report must specify the extent to which work must be stopped and the conditions under which work may resume.
(d)
The permittee is responsible for the actions of its agents, and must notify any agent when a stop work order affects an area within which the agent is working or may work. An agent is any person who acts under the direction, with the permission, or to the benefit of the permittee.
(e)
A person must not continue, or permit the continuance of, work in an area covered by a stop work order.
Montgomery County, Md., Code § 19-44 (2026)
Sec. 19-44. Completion.LinkCopy Citation
(a)
Immediately after a project is finished, the permittee must notify the Department and schedule a final inspection.
(b)
If, after final inspection, the Director finds that all work subject to inspection has been satisfactorily completed in accordance with this article, the permit, approved plans, and regulations, the Director must issue a completion certificate to the permittee. The Director may recommend release of the certificate of occupancy, where applicable, after receiving a completed Elevation Certificate from the developer, at that time.
Montgomery County, Md., Code § 19-45 (2026)
Sec. 19-45. Regulations.LinkCopy Citation
(a)
The Director may recommend written regulations to administer this article, may hold public hearings on any proposed regulation, and must obtain approval from the Floodplain Division of the Maryland Water Resources Administration before forwarding any regulation to the County Executive for adoption.
(b)
The regulations must include but are not limited to the following:
(1)
Accepted floodplain datum sources;
(2)
Floodplain restrictions; and
(3)
Minimum plan requirements.
(c)
The County Executive may adopt regulations authorized by subsection (a) under Method (2).
(d)
The Director may recommend regulations, to be adopted by the County Executive under Method (3), to set, increase, or decrease permit fees.
(e)
Any regulation adopted under this article must not conflict with or waive any provision of this chapter, and must not be less restrictive than regulations of the Maryland Water Resources Administration.
Montgomery County, Md., Code § 19-46 (2026)