Zoning › State preemptions › Massachusetts

Massachusetts Areas of Critical Environmental Concern (ACEC) (MGL c. 21A §2(7)) (MA)

Tracked preemption from the Massachusetts overlay bundle.

Overview

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Effective
1975-01-01
Sunset
—
Authority
state
Scope
state:MA
Other Massachusetts preemptions
Massachusetts Chapter 40Y — Starter Home Zoning Districts (Opt-In)Massachusetts MBTA Communities Act — Multi-Family Zoning Requirement (MGL c. 40A §3A)Massachusetts Chapter 40S — Smart Growth School Cost ReimbursementMassachusetts Chapter 40R — Smart Growth Zoning Overlay District (Opt-In)Massachusetts Rivers Protection Act — Riverfront Area (MGL c. 131 §40)Boston Planning Department (former BPDA) Article 80 Development ReviewMassachusetts Outstanding Resource Waters & DCR Watershed ProtectionCape Cod Commission Regional Land Use Authority (St. 1989, c. 716)

Trigger predicate

When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.

parcel.within_acec == True

Preempted fields

2 fields on the base district schema are rewritten when the trigger fires.

FieldOpValueNote
review_typerequire_additionalmepa_lower_threshold_reviewACEC designation lowers MEPA review thresholds (301 CMR 11.03) — Environmental Notification Form required for many otherwise-exempt projects
base_districts[*].buildable_area_sfconstrainper_301_cmr_12_designation_decisionConservation Commission applies stricter performance standards within ACEC under 310 CMR 10.24(7) and 10.58(4)(d)

Citation

Authority source
MGL c. 21A §2(7); 301 CMR 12.00 (ACEC Regulations); EEA Secretary's designation decisions
§ 301 CMR 12.00; designation by Secretary of Energy and Environmental Affairs
https://www.mass.gov/areas-of-critical-environmental-concern-acec-program

Research notes

30 designated ACECs covering ~270,000 acres statewide (e.g., Pleasant Bay, Sandy Neck Barrier Beach System, Inner Cape Cod Bay, Herring River, Weir River, Hockomock Swamp, Canoe River Aquifer, Neponset River Estuary, Petapawag, Karner Brook, Three Mile River). Designation triggers: (a) lower MEPA review thresholds; (b) stricter DEP wetlands performance standards; (c) DCR / DFG / DEP program priorities; (d) state real-property dispositions subject to additional review. Does not directly override local zoning but layers state review on top. Local bylaws frequently mirror state ACEC standards.