Building near the water in Lexington, Massachusetts (wetlands rules)
Work within 100 feet of a wetland, stream, pond or floodplain in Lexington needs a permit from the Conservation Commission under the town's wetland bylaw. The Commission's rules bar new structures, driveways or paving within 50 feet of a wetland except in extraordinary circumstances, and prohibit removing trees or shrubs within 25 feet.
| Area regulated by the local bylaw | Resource areas plus land within 100 feet [2] |
| Approval needed | Notice of Intent and permit from the Conservation Commission [1] |
| No-build setback | No structures, driveways or paving within 50 feet (except extraordinary circumstances) [5] |
| No-cut zone | No tree, shrub or vegetation removal within 25 feet [7] |
| Max disturbance of buffer zone | 50% of contiguous buffer (or the unvegetated area, if greater) [4] |
| Buildings in floodplain | None below the 10-year flood level [8] |
| Fine | Up to $300 per day [9] |
Where the rules apply
The wetland bylaw text we have is the town's PDF showing amendments through April 2002 and may have changed since; the Conservation Commission's rules are the September 13, 2021 version.
Lexington is inland, so "building near the water" means its wetland bylaw (Code Chapter 130) and the state Wetlands Protection Act, both administered by the Conservation Commission. The bylaw covers banks, wetlands, marshes, swamps, streams, ponds, lakes, vernal pools, land subject to flooding and riverfront area, plus "land bordering thereon": anything within 100 feet of those resource areas or of the 100-year flood elevation [2].
Permits
You may not remove, fill, dredge, build upon or alter any of these areas without filing a Notice of Intent and receiving a permit from the Conservation Commission [1]. If you're unsure whether your project is covered, you can ask the Commission for a written determination, which it must issue within 21 days [3]. Permits (Orders of Conditions) expire after three years.
Buffer zone standards
The Commission's 2021 rules set firm limits inside the 100-foot buffer:
- Construction may disturb no more than 50% of the contiguous buffer zone, or the area not currently vegetated if that is greater, and work should be kept as far from the resource as possible [4].
- The Commission won't approve any structure, roadway, driveway or other constructed surface within 50 feet of a wetland or other resource area except in extraordinary circumstances with substantial improvement over existing conditions [5].
- No removal of trees, shrubs or other vegetation within 25 feet, except approved restoration such as invasive species management [7]. Chemical lawn treatments in the buffer count as an alteration and need Commission approval.
Existing homes inside 50 feet
If a house (footprint over 250 sq ft) is already within 50 feet and the lot makes it impractical to build elsewhere, a replacement or addition may come no closer than the existing structure and must not add impervious surface in the 50-foot buffer, unless extra mitigation yields a net improvement [6].
Floodplain
No building, parking area or outdoor storage may be placed below the 10-year flood level [8]. The Zoning Bylaw also has a floodplain overlay district.
Penalties
Violations can be fined up to $300, with each day a separate offense [9]. This figure comes from the 2002-era bylaw PDF; confirm current penalties with the Conservation Commission.
Next steps
- Check town wetland and flood maps or ask the Conservation Office whether your project is within 100 feet of a wetland, stream, pond or floodplain.
- If you're unsure, file a Request for Determination of Applicability with the Conservation Commission.
- If the work is covered, file a Notice of Intent with plans and the filing fee, and attend the public hearing.
- Keep new structures and paving outside 50 feet and leave vegetation within 25 feet untouched; don't start until you have the Order of Conditions.
Common questions
- Do I need a permit to build near a wetland in Lexington, Massachusetts?
- Yes. Work within 100 feet of a wetland, stream, pond or floodplain needs a permit from the Conservation Commission under the wetland bylaw.
- How close to a wetland can I build in Lexington, Massachusetts?
- The Commission's rules bar new structures, driveways or paving within 50 feet of a wetland except in extraordinary circumstances.
- Can I cut trees near a wetland in Lexington, Massachusetts?
- No. Removing trees or shrubs within 25 feet is prohibited.
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
- Code Ch. 130, §130-2A, Code Chapter 130, Wetland Protection (town PDF), p. 1
A. No person shall remove, fill, dredge, build upon or alter any bank, freshwater wetland, marsh, bog, wet meadow, swamp, creek, river, stream, pond, lake, vernal pool habitat, land under water bodies, land subject to flooding, or any land bordering thereon as hereinafter defined, or riverfront area other than in the course of maintaining, repairing or replacing, but not substantially changing or enlarging, an existing and lawfully located structure or facility used in the service of the public and used to provide electric, gas, water, telephone, telegraph or other telecommunication services without first filing written notice of intent to so remove, fill, dredge, alter or build upon, including such plans as may be necessary to fully describe such proposed activity and its effect on the environment, and without receiving and complying with a permit issued by the Conservation Commission.
- Code Ch. 130, §130-8C(4)(a), Code Chapter 130, Wetland Protection (town PDF), p. 4
(a) One hundred feet horizontally lateral from the edge of any bank, freshwater wetland, bog, marsh, wet meadow, swamp, creek, river, stream, pond, lake, vernal pool habitat, land under water bodies or land subject to flooding.
- Code Ch. 130, §130-2C, Code Chapter 130, Wetland Protection (town PDF), p. 1
C. Upon written request of any person, the Conservation Commission shall within 21 days make a written determination as to whether this by-law is applicable to any land or work thereon.
- Rules, Section 5(5)(1) Buffer Zone, Wetland Protection Rules adopted by the Lexington Conservation Commission (amended 9-13-2021), p. 7
Of contiguous land within the Buffer Zone, construction activities may disturb no more than 50% or the amount not presently supporting a vegetated community as described above, whichever is greater.
- Rules, Section 5(5)(2) Buffer Zone, Wetland Protection Rules adopted by the Lexington Conservation Commission (amended 9-13-2021), p. 8
Even if such a showing is made, the commission will not approve any structure, roadway, driveway, or other constructed surface within 50 feet of an associated Protected Resource Area except in extraordinary circumstances and only if proposed mitigation will result in a substantial improvement over existing conditions.
- Rules, Section 5(5)(3) Buffer Zone, Wetland Protection Rules adopted by the Lexington Conservation Commission (amended 9-13-2021), p. 8
If the previous development includes a structure with a footprint of more than 250 square feet and, because of the size or shape of the lot, it is impracticable to confine a replacement of or addition to that structure to an area outside the 50-foot buffer, that replacement or addition may create a setback of less than 50 feet from the Protected Resource Area, provided (1) that the proposed setback is no less than that from the part of the existing structure that is closest to the Protected Resource Area and (2) that the new construction does not increase the amount of impervious surface within the 50-foot buffer or that, by the application of mitigation measures beyond those normally required by applicable performance standards, the proposed project will result in a net improvement to the capacity of the Buffer Zone to protect the interests set forth in the Lexington Code for Wetland Protection.
- Rules, Section 5(5)(6) Buffer Zone, Wetland Protection Rules adopted by the Lexington Conservation Commission (amended 9-13-2021), p. 8
6. Within 25 feet of an associated Protected Resource Area, there shall be no removal of trees, shrubs or other vegetation unless part of an approved ecological restoration project, including invasive species management.
- Rules, Section 5(3) Structures in Floodplain, Wetland Protection Rules adopted by the Lexington Conservation Commission (amended 9-13-2021), p. 6
No building of any kind, and no parking lot or any other facility for the temporary or permanent storage of automobiles, trucks, or other material shall be located below the 10-year flood level.
- Code Ch. 130, §130-12, Code Chapter 130, Wetland Protection (town PDF), p. 7
Whoever violates any provision of this by-law shall be punished by a fine of not more than $300. Each day or portion thereof of continuing violation shall constitute a separate offense.