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Chelmsford City Zoning Code

ARTICLE XV

Floodplain District

§ 195-76 Purpose.

The purposes of this district are to:
A. 
Provide that the lands in the Town of Chelmsford subject to seasonal or periodic flooding as described hereinafter shall not be used for residence or other purposes in such manner as to endanger the health or safety of the occupants thereof.
B. 
Protect, preserve and maintain the water table and water recharge areas within the Town so as to preserve present and potential water supplies for the public health and safety of the residents of the Town of Chelmsford.
C. 
Assure the continuation of the natural flow of the watercourse(s) within the Town of Chelmsford in order to provide adequate and safe floodwater storage capacity to protect persons and property against the hazards of flood inundation.
D. 
Ensure public safety through reducing the threats to life and personal injury.
E. 
Eliminate new hazards to emergency response officials.
F. 
Prevent the occurrence of public emergencies resulting from water quality, contamination, and pollution due to flooding.
G. 
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.
H. 
Eliminate costs associated with the response and cleanup of flooding conditions.
I. 
Reduce damage to public and private property resulting from flooding waters.

§ 195-76.1 Definitions.

DEVELOPMENT
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, 44 CFR 59]
FLOOD BOUNDARY AND FLOODWAY MAP
Means an official map of a community issued by FEMA that depicts, based on detailed analyses, the boundaries of the 100-year and 500-year floods and the 100-year floodway. (For maps done in 1987 and later, the floodway designation is included on the FIRM.) (if applicable in your community)
FLOOD HAZARD BOUNDARY MAP (FHBM)
An official map of a community issued by the Federal Insurance Administrator, where the boundaries of the flood and related erosion areas having special hazards have been designated as Zone A or E. [US Code of Federal Regulations, 44 CFR 59] (if applicable in your community).
FLOODWAY
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]
FUNCTIONALLY DEPENDENT USE
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, 44 CFR 59] Also [Referenced Standard ASCE 24-14]
HIGHEST ADJACENT GRADE
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, 44 CFR 59]
HISTORIC STRUCTURE
Means any structure that is:
A. 
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;
B. 
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;
C. 
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
D. 
Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:
(1) 
By an approved state program as determined by the Secretary of the Interior or
(2) 
Directly by the Secretary of the Interior in states without approved programs.
[US Code of Federal Regulations, 44 CFR 59]
NEW CONSTRUCTION
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]
RECREATIONAL VEHICLE
Means a vehicle which is:
A. 
Built on a single chassis;
B. 
400 square feet or less when measured at the largest horizontal projection;
C. 
Designed to be self-propelled or permanently towable by a light duty truck; and
D. 
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, 44 CFR 59]
REGULATORY FLOODWAY
See "floodway."
SPECIAL FLOOD HAZARD AREA
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, V, VO, VE or V1-30. [Base Code, Chapter 2, Section 202]
START OF CONSTRUCTION
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]
STRUCTURE
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, 44 CFR 59]
SUBSTANTIAL REPAIR OF A FOUNDATION
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 101 et seq. [As amended by MA in 9th Edition BC]
VARIANCE
Means a grant of relief by a community from the terms of a flood plain management regulation. [US Code of Federal Regulations, 44 CFR 59]
VIOLATION
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, 44 CFR 59]

§ 195-77 Overlay district; boundaries.

The Floodplain District and Floodway District is herein established as an overlay district. The underlying permitted uses are allowed, provided that they meet the following additional requirements as well as those of the Massachusetts State Building Code dealing with construction in floodplains. The Floodplain District and Floodway District includes all special flood hazard areas within the Town of Chelmsford designated as Zone A and AL 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 dated July 8, 2025. The exact boundaries of the District may be defined by the 100-year 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, Inspector of Buildings and Conservation Commission.

§ 195-77.1 Designation of community Floodplain Administrator.

The Town of Chelmsford hereby designates the position of Community Development Director to be the official floodplain administrator for the Town.

§ 195-78 Base flood elevation and floodway data.

A. 
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.
B. 
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.
C. 
Base flood elevation data. Base flood elevation data is required for subdivision proposals or other developments greater than 50 lots or five acres, whichever is the lesser, within unnumbered A zones.
D. 
Base flood elevation data for subdivision proposals. 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.

§ 195-79 Notification of watercourse alteration and requirement to submit new technical data.

In a riverine situation, the Floodplain Manager shall notify the following of any alteration or relocation of a watercourse:
A. 
Adjacent communities, especially upstream and downstream.
B. 
Bordering states, if affected.
C. 
NFIP State Coordinator. Massachusetts Department of Conservation and Recreation.
D. 
NFIP Program Specialist, FEMA Region I. Federal Emergency Management Agency, Region I.
If the Town/City 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) to Subsections C and D above.

§ 195-80 Use regulations.

The Floodplain District is established as an overlay district to all other districts.
A. 
The Town of Chelmsford requires a permit 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.
B. 
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. The proponent must acquire all necessary permits, and must demonstrate that all necessary permits have been acquired.
C. 
Variances to Building Code floodplain standards
The Town/City 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/City 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.
D. 
Variances to local Zoning By laws related to community compliance with the National Flood Insurance Program (NFIP). A variance from these floodplain bylaws must meet the requirements set out by State law, 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.
E. 
Recreational vehicles. 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.
F. 
Except as permitted in § 195-82, in the Floodplain District, no new building shall be erected or constructed and no existing structure shall be altered, enlarged or moved, no dumping, filling or earth transfer or relocation shall be permitted and no land, building or structure shall be used for any purposes except:
(1) 
Conservation of water, plants and wildlife.
(2) 
Outdoor recreation, including play areas, nature study, boating, fishing and hunting, where otherwise legally permitted, but excluding buildings and structures.
(3) 
Noncommercial signs (as permitted in the residential districts), wildlife management areas, foot, bicycle, and/or horse paths and bridges, provided that such uses do not affect the natural flow pattern of watercourses.
(4) 
Grazing and farming, including truck gardening and harvesting of crops.
(5) 
Forestry and nurseries.
G. 
All subdivision proposals must be designed to assure that:
(1) 
Such proposals minimize flood damage;
(2) 
All public utilities and facilities are located and constructed to minimize or eliminate flood damage: and
(3) 
Adequate drainage is provided to reduce exposure to flood hazards.

§ 195-81 Floodway regulations.

In the floodway, designated on the Flood Insurance Rate Map, the following provisions shall apply:
A. 
All encroachments, including fill, new construction, substantial improvements to existing structures and other development, are prohibited 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.
B. 
Any encroachment meeting the above standard shall comply with the floodplain requirements of the State Building Code.
C. 
If a property owner questions the location of a floodplain or floodway district. The owner may engage, at the owner's own cost, a registered licensed surveyor with the approval of the Town Engineer to determine if the land in question is within the floodplain or floodway district. The landowner shall be responsible for the cost for this determination. The Board of Appeals, in consultation with the Town Engineer, shall decide whether or not to accept the surveyor's determination. Per § 195-79, 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.)
D. 
No new building or portion thereof located within the Floodplain District shall be allowed to connect to the municipal wastewater system or to a private wastewater system that discharges to the municipal wastewater system.
E. 
The portion of any lot within the area delineated in § 195-77 above may be used to meet the area and yard requirements for the district or districts in which the remainder of the lot is situated.

§ 195-82 Special permits.

In the floodplain District, the Board of Appeals may grant a special permit for exception for uses or structures in addition to those allowed under § 195-80, subject to the following:
A. 
The applicant has referred the request to the Planning Board, the Town Engineer, the Board of Health and the Conservation Commission for review and recommendation as provided in MGL c. 40A, § 11:
B. 
The land is shown to be neither subject to flooding nor unsuitable for the proposed use because of hydrologic and/or topographic conditions:
C. 
The proposed use will not be detrimental to the public health, safety and welfare:
D. 
The proposed use will comply in all respects with the provisions of the underlying district or districts within which the land is located: and
E. 
Any loss of floodplain or floodway shall be compensated for at a similar elevation within the same local watershed.
A variance from these floodplain bylaws must meet the requirements set out by State law, 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.

§ 195-82.1 Abrogation and greater restriction.

The floodplain management regulations found in this Floodplain Overlay District section shall take precedence over any less restrictive conflicting local laws, ordinances or codes.

§ 195-82.2 Disclaimer of liability.

The degree of flood protection required by this bylaw is considered reasonable but does not imply total flood protection.

§ 195-82.3 Severability.

If any section, provision or portion of this bylaw is deemed to be unconstitutional or invalid by a court, the remainder of the ordinance shall be effective.