Building near the water in Belmont, Massachusetts (wetlands rules)
Belmont has no local wetlands bylaw in the documents we reviewed, so work near brooks, ponds and wetlands is reviewed by the Conservation Commission under the state Wetlands Protection Act. The Zoning By-Law adds a Floodplain District (FEMA Zones A and AE) where new buildings are prohibited and substantial improvements to existing homes need a special permit from the Zoning Board of Appeals.
| Floodplain District | FEMA Zone A and AE areas on the June 4, 2010 Middlesex County FIRM [1] |
| New buildings in the floodplain | Prohibited [2] |
| Additions to existing homes in the floodplain | Allowed; substantial improvements need a ZBA special permit [3] |
| State rules that apply | State Building Code flood provisions, Wetlands Protection (310 CMR 10.00), Inland Wetlands Restriction (310 CMR 13.00), Title 5 [4] |
| Review of floodplain special permits | Referred to Planning Board, Board of Health and Conservation Commission [5] |
| Wetlands and lot area | At least 90% of required lot area must be outside Wetlands Protection Act resource areas [6] |
No local wetlands bylaw
Massachusetts has no shoreland zoning; building near water is governed by the Wetlands Protection Act, administered by the Conservation Commission. We didn't find a local Belmont wetlands bylaw, so the state rules (including the 100-foot buffer zone and 200-foot riverfront area) are what the Conservation Commission applies. File a Request for Determination of Applicability or Notice of Intent before working near a wetland, brook or pond.
Floodplain District
The Zoning By-Law sets up a Floodplain District as an overlay covering FEMA Zone A and AE special flood hazard areas on the June 4, 2010 Middlesex County flood maps [1]. Inside it, new buildings or structures are prohibited, as is filling or excavation that would restrict flood flow or reduce flood storage [2]. Additions and alterations to an existing structure are permitted, but if the work is a substantial improvement (costing 50% or more of the structure's market value) it needs a special permit from the Zoning Board of Appeals [3].
All development in the district must comply with the State Building Code's flood provisions, the state wetlands regulations (310 CMR 10.00), the Inland Wetlands Restriction (310 CMR 13.00) and Title 5 [4]. Special permit applications go to the Planning Board, Board of Health and Conservation Commission for comment [5], and no encroachment in a regulatory floodway may raise flood levels. If you get a FEMA Letter of Map Amendment or Revision showing your site is above the base flood elevation, the Building Commissioner may waive the floodplain rules.
Wetlands and buildable lot area
At least 90% of the lot area needed to meet zoning minimums must be outside areas protected by the Wetlands Protection Act (other than for flooding) [6], which matters if you're dividing land or building a new house.
Next steps
- Check the FEMA flood map (or ask the Building Division, 617-993-2650) to see if your property is in Zone A or AE.
- Before any work within 100 ft of a wetland, brook or pond (or 200 ft of a river), contact the Belmont Conservation Commission and file an RDA or Notice of Intent.
- If you're in the Floodplain District and your project is a substantial improvement, apply to the Zoning Board of Appeals for a special permit.
- If you believe your site is above the base flood elevation, get a FEMA Letter of Map Amendment and ask the Building Commissioner for a waiver.
Common questions
- Do I need a permit to build near a wetland or pond in Belmont, Massachusetts?
- Belmont has no local wetlands bylaw in the documents reviewed, so the Conservation Commission reviews work near wetlands, brooks and ponds under the state Wetlands Protection Act. File a Request for Determination of Applicability or Notice of Intent first.
- Can I build in a floodplain in Belmont, Massachusetts?
- New buildings are prohibited in the Floodplain District (FEMA Zones A and AE). Additions to existing homes are allowed, but a substantial improvement needs a special permit from the Zoning Board of Appeals.
- What counts as a substantial improvement in the Belmont, Massachusetts floodplain?
- Work costing 50% or more of the structure's market value. It needs a Zoning Board of Appeals special permit.
- How much of my lot must be outside wetlands in Belmont, Massachusetts?
- At least 90% of the lot area needed to meet zoning minimums must be outside areas protected by the Wetlands Protection Act, other than for flooding.
Massachusetts wetlands rules and the Conservation Commission
Massachusetts has no "shoreland zoning" like some states. Instead, the Wetlands Protection Act (M.G.L. c. 131, §40) and MassDEP's regulations (310 CMR 10.00) control work near water, and your local Conservation Commission enforces them.
What's protected:
- Wetlands, banks, beaches, dunes, marshes, land under ponds and streams, and 100-year floodplains.
- The riverfront area: 200 feet from a perennial river or stream, shrinking to 25 feet in certain dense urban areas.
- The buffer zone: land within 100 feet of a wetland, bank, beach or similar resource area. Most work here needs Conservation Commission review.
How approval works:
- Contact the Conservation Commission before starting any work in these areas. That includes additions, decks, sheds, driveways, regrading and clearing vegetation.
- If you're unsure whether the law applies, file a Request for Determination of Applicability (RDA).
- If the work will affect a resource area, file a Notice of Intent (NOI) with plans and a fee. A public hearing follows, and the commission issues an Order of Conditions approving (with conditions) or denying the project.
- Applicants, abutters, groups of 10 residents or MassDEP can appeal to MassDEP.
Local bylaws can be stricter. Many towns have their own wetlands bylaw with larger buffers or no-build zones, and the Conservation Commission enforces those too.
What the bylaw says
- §2.4 Floodplain District Delineation, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 32
The Floodplain District is herein established as an overlay district. The District includes all special flood hazard areas within the Town of Belmont designated as Zone A and AE, on the Middlesex County Flood Insurance Rate Map (FIRM) issued by the Federal Emergency Management Agency (FEMA) for the administration of the National Flood Insurance Program.
- §6.6.3(b) Use Regulations, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 90
b) Except as provided below, the following shall be prohibited in the Floodplain District: 1. New buildings or structures.
- §6.6.3(c)(5) Use Regulations, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 90
5. Addition or alteration to an existing structure, but if constituting a substantial improvement (see definition), only if authorized by Special Permit from the Board of Appeals.
- §6.6.4 Requirements, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 90
All development in this District, including structural and nonstructural activities, whether permitted by-right or allowed by Special Permit, must be in compliance with the following:
- §6.6.6 Special Permit, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 91
Upon their receipt, applications for Special Permits in the Floodplain District shall be referred to the Planning Board, Board of Health, and Conservation Commission for their review and comment.
- §1.4 Definitions, Lot Area, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 15
At least 90% of the lot area required for compliance shall also be exclusive of areas subject to protection under the Wetlands Protection Act, Section 40, Chapter 131, Massachusetts General Law, for reasons other than being subject to flooding.