Groton City Zoning Code
§ 218-7.1
Floodplain District regulations.
[Amended 4-26-2025 ATM by Art. 14]
A.
The purpose of the Floodplain Overlay District and this Floodplain Bylaw is to:
(1)
Ensure public safety through reducing the threats to life and personal injury;
(2)
Eliminate new hazards to emergency response officials;
(3)
Prevent the occurrence of public emergencies resulting from water quality, contamination, and pollution due to flooding;
(4)
Avoid the loss of utility services which if damaged by flooding would disrupt or shut down the utility network and impact regions of the community beyond the site of flooding;
(5)
Eliminate costs associated with the response and cleanup of flooding conditions;
(6)
Reduce damage to public and private property resulting from flooding waters.
B.
The Floodplain Overlay District is established as an overlay district. The Floodplain Overlay District includes all special flood hazard areas within the Town of Groton designated as Zone A, AE on the Middlesex County Flood Insurance Rate Map (FIRM) dated July 8, 2025, issued by the Federal Emergency Management Agency (FEMA) for the administration of the National Flood Insurance Program. The exact boundaries of the Floodplain Overlay District shall be defined by the 1% chance base flood elevations shown on the FIRM and further defined by the Middlesex County Flood Insurance Study (FIS) report dated July 8, 2025. The FIRM and FIS report are incorporated herein by reference and are on file with the Town Clerk, Planning Board, Building Commissioner, and Conservation Commission.
C.
The Building Commissioner shall be the official floodplain administrator for the Town and floodplain permit granting authority under this Floodplain Bylaw.
D.
No new building or structure shall be erected in the Floodplain Overlay District except in accordance with this § 218-7.1.
E.
The Town of Groton requires a floodplain permit issued by the Building Commissioner for all proposed construction or other development in the Floodplain Overlay District, including new construction or changes to existing buildings, placement of manufactured homes, placement of agricultural facilities, fences, sheds, storage facilities or drilling, mining, paving and any other development that might increase flooding or adversely impact flood risks to other properties.
F.
The Town's permit review process includes the requirement that the proponent obtain all local, state and federal permits that will be necessary in order to carry out the proposed development in the Floodplain Overlay District prior to the commencement of work authorized by the Building Commissioner under this Floodplain Bylaw. The proponent must acquire all necessary permits, and must demonstrate that all necessary permits have been acquired.
G.
In Zones A and AE, along watercourses that have not had a regulatory floodway designated, the best available Federal, State, local, or other floodway data shall be used to prohibit encroachments in floodways which would result in any increase in flood levels within the community during the occurrence of the base flood discharge.
(1)
In Zone AE, along watercourses that have a regulatory floodway designated on the Town's FIRM encroachments are prohibited, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.
H.
In A Zones, in the absence of FEMA BFE data and floodway data, the building department will obtain, review and reasonably utilize base flood elevation and floodway data available from a Federal, State, or other source as criteria for requiring new construction, substantial improvements, or other development in Zone A and as the basis for elevating residential structures to or above base flood level, for floodproofing or elevating nonresidential structures to or above base flood level, and for prohibiting encroachments in floodways.
J.
When proposing subdivisions or other developments greater than 50 lots or five acres (whichever is less), the proponent must provide technical data to determine base flood elevations for each developable parcel shown on the design plans.
K.
In A and AE Zones, all recreational vehicles to be placed on a site must be elevated and anchored in accordance with the zone's regulations for foundation and elevation requirements or be on the site for less than 180 consecutive days or be fully licensed and highway ready.
L.
In a riverine situation, the Building Commissioner shall notify the following of any alteration or relocation of a watercourse:
M.
If the Town acquires data that changes the base flood elevation in the FEMA mapped Special Flood Hazard Areas, the Town will, within six months, notify FEMA of these changes by submitting the technical or scientific data that supports the change(s). Notification shall be submitted to:
N.
Variances to building code floodplain standards. The Town will request from the State Building Code Appeals Board a written and/or audible copy of the portion of the hearing related to the variance, and will maintain this record in the community's files. The Town shall also issue a letter to the property owner regarding potential impacts to the annual premiums for the flood insurance policy covering that property, in writing over the signature of a community official that i) the issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage and ii) such construction below the base flood level increases risks to life and property. Such notification shall be maintained with the record of all variance actions for the referenced development in the Floodplain Overlay District.
O.
Variances to local Zoning Bylaws related to community compliance with the National Flood Insurance Program (NFIP). A variance from this Floodplain Bylaw must meet the requirements set out by state law, as applicable, and may only be granted if: 1) Good and sufficient cause and exceptional non-financial hardship exist; 2) the variance will not result in additional threats to public safety, extraordinary public expense, or fraud or victimization of the public; and 3) the variance is the minimum action necessary to afford relief. A variance under this Floodplain Bylaw shall be distinct from a variance under M.G.L. c. 40A, § 10, and § 218-2.4 of the Zoning Bylaw.
P.
The floodplain management regulations found in this Floodplain Overlay District section shall take precedence over any less restrictive conflicting local laws, ordinances or codes.
Q.
The degree of flood protection required by this Floodplain Bylaw is considered reasonable but does not imply total flood protection.
R.
If any section, provision, or portion of this Floodplain Bylaw is deemed to be unconstitutional or invalid by a court, the remainder of the ordinance shall be effective.
S. DEVELOPMENT FLOODWAY FUNCTIONALLY DEPENDENT USE HIGHEST ADJACENT GRADE HISTORIC STRUCTURE(1) (2) (3) (4) NEW CONSTRUCTION RECREATIONAL VEHICLE(1) (2) (3) (4) REGULATORY FLOODWAY SPECIAL FLOOD HAZARD AREA START OF CONSTRUCTION STRUCTURE SUBSTANTIAL REPAIR OF A FOUNDATION VARIANCE VIOLATION
Definitions not found in the State Building Code, which are applicable only within this Floodplain Bylaw and do not govern other sections of the Zoning Bylaw.
Means any man-made change to improved or unimproved real estate, including but not limited to building or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials. [US Code of Federal Regulations, Title 44, Part 59]
The channel of the river, creek or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height. [Base Code, Chapter 2, Section 202]
Means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, but does not include long-term storage or related manufacturing facilities. [US Code of Federal Regulations, Title 44, Part 59] Also [Referenced Standard ASCE 24-14]
Means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. [US Code of Federal Regulations, Title 44, Part 59]
Means any structure that is:
Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;
Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;
Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or
Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:
Structures for which the start of construction commenced on or after the effective date of the first floodplain management code, regulation, ordinance, or standard adopted by the authority having jurisdiction, including any subsequent improvements to such structures. New construction includes work determined to be substantial improvement. [Referenced Standard ASCE 24-14]
Means a vehicle which is:
Built on a single chassis;
400 square feet or less when measured at the largest horizontal projection;
Designed to be self-propelled or permanently towable by a light duty truck; and
Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. [US Code of Federal Regulations, Title 44, Part 59]
See "floodway."
The land area subject to flood hazards and shown on a Flood Insurance Rate Map or other flood hazard map as Zone A, AE, A1-30, A99, AR, AO, AH. [Base Code, Chapter 2, Section 202]
The date of issuance for new construction and substantial improvements to existing structures, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement or other improvement is within 180 days after the date of issuance. The actual start of construction means the first placement of permanent construction of a building (including a manufactured home) on a site, such as the pouring of a slab or footings, installation of pilings or construction of columns. Permanent construction does not include land preparation (such as clearing, excavation, grading or filling), the installation of streets or walkways, excavation for a basement, footings, piers or foundations, the erection of temporary forms or the installation of accessory buildings such as garages or sheds not occupied as dwelling units or not part of the main building. For a substantial improvement, the actual "start of construction" means the first alteration of any wall, ceiling, floor or other structural part of a building, whether or not that alteration affects the external dimensions of the building. [Base Code, Chapter 2, Section 202]
Means, for floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. [US Code of Federal Regulations, Title 44, Part 59]
When work to repair or replace a foundation results in the repair or replacement of a portion of the foundation with a perimeter along the base of the foundation that equals or exceeds 50% of the perimeter of the base of the foundation measured in linear feet, or repair or replacement of 50% of the piles, columns or piers of a pile, column or pier supported foundation, the building official shall determine it to be substantial repair of a foundation. Applications determined by the building official to constitute substantial repair of a foundation shall require all existing portions of the entire building or structure to meet the requirements of 780 CMR. [As amended by MA in 9th Edition BC]
Means a grant of relief by a community from the terms of a flood plain management regulation. [US Code of Federal Regulations, Title 44, Part 59]
Means the failure of a structure or other development to be fully compliant with the community's flood plain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in § 60.3 is presumed to be in violation until such time as that documentation is provided. [US Code of Federal Regulations, Title 44, Part 59]