Montgomery County, MD Environmental Rules: Flood Zones (2026)
FEMA flood zone rules in Montgomery County, MD, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.
Key Facts
- Permit trigger
- Land disturbance in floodplain or buffer
- Minor-work exemption
- Under 5,000 sq ft, promptly stabilized
- Building permit bar
- No new structures in 100-year floodplain
- Enforcing agency
- Dept. of Permitting Services
- Max penalty
- $1,000 fine or 6 months jail
Summary
Montgomery County requires a floodplain district permit for any land-disturbing activity within the mapped floodplain or its 25-foot buffer, and generally bars building permits for new structures on 100-year floodplain land.
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
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-90: Montgomery County Code contains legislation effective through May 7, 2026 | Zoning Updated Effective: April 13, 2026 | COMCOR Regulations effective as of July 1, 2026).
Full Breakdown
Under County Code § 19-37, no one may disturb land within the floodplain district or within 25 feet of its boundary without a Department of Permitting Services floodplain district permit; minor disturbances under 5,000 square feet that are promptly stabilized are exempt, as is accepted agricultural practice and state/federal land. Separately, § 8-29 bars the Director from issuing a building permit for any structure on land within the 100-year floodplain of a stream or drainage course, except for fences, utilities, recreation, agricultural uses, and repair of existing single-family homes. On-site sewage systems are also barred from the floodplain.
Violations & Fines
Violating Chapter 19's floodplain permit requirement is a Class A violation: up to $1,000 and 6 months in jail criminally, or a $500 civil fine ($750 for repeats), with each day a separate offense.
Frequently Asked Questions
Do I need a permit to grade my yard near a stream in Montgomery County?
Can I get a building permit to build a new house in the 100-year floodplain?
Sources & Official References
Other rules in Montgomery County
Compare Montgomery County to another location·View the Maryland environmental rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.