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Floodplains, RPAs, wetlands and stormwater in Montgomery County, MD

Work in a mapped floodplain needs a floodplain district permit (County Code Ch. 19, Art. III). Stream valley buffers and wetlands are reviewed with sediment control permits. Montgomery has no Virginia-style RPA and no tidal Critical Area.

A person last checked these rules on October 20, 2026. This is guidance only, so confirm with Montgomery County before you build.

The details

  • Sediment control permit above 5,000 sq ft or 100 cubic yards.High confidence
  • Floodplain permits come from Chapter 19, § 19-37.High confidence

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Common questions

What if my lot is in a floodplain, Resource Protection Area or wetland in Montgomery County?
Work in a mapped floodplain needs a floodplain district permit (County Code Ch. 19, Art. III). Stream valley buffers and wetlands are reviewed with sediment control permits. Montgomery has no Virginia-style RPA and no tidal Critical Area.

Sources

  1. Montgomery County DPS, Permits Required list (land disturbance). Checked 2026-10-21
    Land Disturbance (greater than 5,000 square feet or 100 cubic yards or more of earth movement) [likely requires a permit].
  2. Montgomery County Code Chapter 55, Tree Canopy Law, § 55-4 Applicability; Chapter 19 Article III floodplain district permits. Checked 2026-10-21
    [§ 55-4] Except as otherwise provided in Section 55-5, this Chapter applies to any person required by law to obtain a sediment control permit. [§ 55-5] This Chapter does not apply to: (a) any activity that is subject to Article II of Chapter 22A [Forest Con…

Disclaimer: This is general information, not legal or professional advice for any one property. Codes change. SetbackIQ is not a zoning determination, a permit, or a survey, and it does not replace an architect, engineer, or lawyer. Confirm with your building and zoning offices before you build, buy, or sign a contract.