The purpose of this article is to prevent the deterioration of and promote the restoration of groundwater levels in the City of Boston. The requirements of this article aim to protect and enhance the City of Boston's areas and structures supported on wood pile foundations that are at risk of ground water depletion, conserve the value and structural integrity of its land and buildings, and reduce surface water runoff and water pollution.

(Text Amd. No. 487, § 1, 10-28-2025)

A Groundwater Conservation Overlay District (GCOD), a type of special purpose overlay district established pursuant to Section 3-1A, shall be potentially applicable in areas at risk of groundwater depletion.

The geographic area of the district may be indicated by the designation of "Groundwater Conservation Overlay District" or the abbreviation "GCOD" on any official zoning map of the City of Boston.

An official zoning map indicating the locations of GCOD can be referenced below as well as in the All Zoning Maps section of the Boston Zoning Code as the Article 32 Map.

Groundwater Conservation Overlay District (Article 32 Map)

(Text Amd. No. 487, § 1, 10-28-2025)

1.

Applicability for Dig Down, Lot Coverage, and Paving Projects. Any Applicant seeking a building permit for a Proposed Project within a Groundwater Conservation Overlay District shall be subject to the requirements of this Section 32-3 where such Applicant seeks:

a.

The erection or extension of any structure designed or used for human occupancy or access, mechanical equipment, or laundry or storage facilities, including garage space, if such construction involves the excavation below grade to a depth equal to or below eight (8) feet Boston City Base (other than where such excavation is necessary for, and to the extent limited to, compliance with the requirements of this article).

b.

The erection or extension of any structure, where such new structure or extension will increase the Lot Area covered by the Ground Floor of each building on the Lot by more than fifty (50) square feet; or

c.

Any new or replacement paving of an existing paved surface.

2.

Procedure for Permitting Dig Down, Lot Coverage, and Paving Projects. The Applicant shall submit a GCOD certification pursuant to Section 32-3.3 with the Applicant's notice of appeal to the City of Boston Zoning Board of Appeal. Following receipt of the Applicant's notice of appeal, the issuance of a conditional use permit shall be conditioned upon a staff review of the Applicant's GCOD certification by representatives from the Inspectional Services Department, Boston Water & Sewer Commission, and Boston Groundwater Trust. Should such review by any of the staff find that the Proposed Project's GCOD certification does not comply with the standards of Section 32-3.3, it will be regarded as non-compliance, which will result in a refusal of approval for the issuance of a conditional use permit.

3.

Certification of Standards for Dig Down, Lot Coverage, and Paving Projects. To obtain a conditional use permit that is required for any Proposed Project subject to this Section 32-3, the Applicant shall provide a GCOD certification from a Massachusetts registered engineer that the Proposed Project complies with the following requirements:

a.

Such Proposed Project promotes infiltration of rainwater into the ground by capturing within a suitably-designed system a volume of rainfall on the Lot equivalent to no less than 1.0 inches across that area of the Lot occupied by structures or otherwise impervious surface, except in the case of a proposed Institutional Project not otherwise part of an Institutional Master Plan, then that portion of the surface area of the Lot to be occupied by the Proposed Project; and

b.

Such Proposed Project results in no negative impact on groundwater levels within the Lot in question or adjacent Lots, subject to the terms of any:

i.

Dewatering permit; or

ii.

Cooperation agreement entered into by the Proponent and the Boston Redevelopment Authority, to the extent that such agreement provides standards for groundwater protection during construction.

An Applicant's compliance with Subsection (a) of this Section 32-3.3 in itself will not be deemed to be evidence of the Applicant's compliance with Subsection (b) of this Section 32-3.3.

Such GCOD certification shall include drawings and specifications for the Applicant's proposed rainwater infiltration system, and state the substance of the facts and opinions upon which it is based and a summary of the grounds for each opinion. In this regard, the Applicant bears the specific burden of demonstrating that the Proposed Project will not result in a negative impact on groundwater levels within the Lot or adjacent Lots. With respect to a Proposed Project for a one, two, or three-unit residence, the Applicant may demonstrate presumptive compliance with the rainwater capture requirements of

Subsection (a) of this Section 32-3.3 by designing and constructing such system pursuant to pertinent specifications approved by the Commissioner of Inspectional Services.

(Text Amd. No. 487, § 1, 10-28-2025)

1.

Applicability for Substantial Rehabilitation. Any Applicant seeking a building permit for a Proposed Project within a Groundwater Conservation Overlay District shall be subject to the requirements of this Section 32-4 where such Applicant seeks to:

a.

Substantially Rehabilitate any structure.

2.

Procedure for Permitting Substantial Rehabilitation Projects. The Applicant shall submit a GCOD certification pursuant to Section 32-4.3 with the Applicant's building permit application to the Inspectional Services Department. Following receipt of the Applicant's building permit application, the issuance of any such building permit shall be conditioned upon a staff review of the Applicant's GCOD certification by representatives from the Inspectional Services Department, Boston Water & Sewer Commission, and Boston Groundwater Trust. Should such review by any of the staff find that the Proposed Project's GCOD certification does not comply with the standards of Section 32-4.3, it will be regarded as non-compliance, which will result in a refusal of approval for the issuance of a building permit by the Inspectional Services Department.

3.

Certification of Standards for Substantial Rehabilitation. To obtain a building permit for any Proposed Project subject to this Section 32-4, the Applicant shall provide a GCOD certification from a Massachusetts registered engineer that the Proposed Project complies with the following requirements:

a.

Such Proposed Project promotes infiltration of rainwater into the ground by capturing within a suitably-designed system a volume of rainfall on the Lot equivalent to no less than 1.0 inches across that area of the Lot occupied by structures or otherwise impervious surface, except in the case of a proposed Institutional Project not otherwise part of an Institutional Master Plan, then the Lot area occupied by the structure to be Substantially Rehabilitated; and

b.

Such Proposed Project results in no negative impact on groundwater levels within the Lot in question or adjacent Lots, subject to the terms of any:

i.

Dewatering permit; or

ii.

Cooperation agreement entered into by the Proponent and the Boston Redevelopment Authority, to the extent that such agreement provides standards for groundwater protection during construction.

An Applicant's compliance with Subsection (a) of this Section 32-4.3 in itself will not be deemed to be evidence of the Applicant's compliance with Subsection (b) of this Section 32-4.3.

Such GCOD certification shall include drawings and specifications for the Applicant's proposed rainwater infiltration system and state the substance of the facts and opinions upon which it is based and a summary of the grounds for each opinion. In this regard, the Applicant bears the specific burden of demonstrating that the Proposed Project will not result in a negative impact on groundwater levels within the Lot or adjacent Lots. With respect to a Proposed Project for a one, two, or three-unit residence, the Applicant may demonstrate presumptive compliance with the rainwater capture requirements of Subsection (a) of this Section 32-4.3 by designing and constructing such system pursuant to pertinent specifications approved by the Commissioner of Inspectional Services.

(Text Amd. No. 487, § 1, 10-28-2025)