Purpose and findings: By and through enactment of this article, it has been determined that the wetlands and buffers within the City of Nashua are fragile natural resources and, as such, pursuant to the authority granted under RSA 674:16, 674:17 and 674:20, and 674:21, and any other applicable laws, the City hereby adopts the following regulations. The purpose of this article is, in the interest of public health, safety and general welfare, to:
Ensure the protection of valuable wetland and buffer resources;
Prevent the harmful filling, draining, sedimentation, or alteration of wetlands and buffers;
Prevent the destruction or significant degradation of wetlands and buffers which provide flood and storm control by the hydrologic absorption and storage capacity of the wetland and buffer;
Protect fish and wildlife habitats by providing breeding, nesting, and feeding grounds for many forms of plant and animal life including rare, threatened, or endangered species;
Protect subsurface water resources and provide for the recharging of groundwater supplies;
Provide pollution treatment to maintain water quality;
Prevent expenditures of municipal funds for the purpose of providing and/or maintaining essential services and utilities which might be required as a result of misuse or abuse of wetlands and buffers;
Provide for those compatible land uses in and adjacent to wetlands and buffers or surface waters which serve to enhance, preserve, and protect wetland and buffer areas as natural resources.
A. 
Regulation of land uses. The regulation of land uses both within and adjacent to wetlands, having been determined to be in the best interest of the City, shall be done in a manner consistent with the review procedures and performance standards identified below which reflect the relative importance, value, and function of a particular wetland.
B. 
Definitions. A "wetland" is defined by RSA 482-A:2. Wetlands generally include areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal conditions does support, a prevalence of vegetation typically adapted for life in saturated soil conditions. The location of a wetland boundary in any particular case must be determined by a certified wetlands scientist, licensed by the State of New Hampshire, through an on-site inspection of all three characteristics of wetlands, namely hydrology, hydric soils, and hydrophytic plants. Said inspections shall conform to the standards established by the New Hampshire Department of Environmental Services in Administrative Rules (Wt 301). These standards are derived from three sources: the Corps of Engineers Wetlands Delineation Manual, Technical Report Y-87-I, Environmental Laboratory, Department of the Army, (January, 1987), Field Indicators for Identifying Hydric Soils in New England, Version 2, New England Interstate Water Pollution Control Commission, (July 1998) and subsequent updates, and Chapters Wt 100-800 of the NH Code of Administrative Rules, April 21, 1997, as amended. The applicable criteria and review process are established in this Article XI, §§ 190-112 to 190-117 below.
C. 
Shoreland exemption. All areas granted a shoreland exemption pursuant to RSA 483-B:12 from the Comprehensive Shoreland Protection Act, RSA 483-B, shall not be designated as a prime wetland pursuant to RSA 482-A:15 or Article XI, Wetlands. Any inconsistent provisions of the Prime Wetland Map as prepared by the Nashua Conservation Commission and adopted by Resolution R-90-84 are hereby repealed. Proposed development in the exempt area requiring Planning Board approval shall be referred to the Nashua Conservation Commission for its review and comment prior to the Planning Board decision.
[Added 3-8-2011 by Ord. No. O-11-53]
A. 
Special exceptions shall be reviewed for any use, building, structure, or development within the wetland areas or buffers defined in Table 112-1 below.
B. 
For purposes of Table 112-1, Column C, the buffer shall be measured horizontally outward and perpendicular to the edge of the delineated wetland.
Table 112-1
Wetland Classifications and Buffers
[Amended 12-13-2023 by Ord. No. O-23-059]
(A)
Wetland Category
(B)
Definitions
(C)
Buffer
(feet)
Primary wetland
Areas designated as "prime wetlands" in accordance with RSA 483-A:7 and areas that have been documented as satisfying the criteria for designation as prime wetlands in accordance with RSA 483-A:7. "Primary wetlands" are defined by Resolution R-90-84, and generally depicted on maps entitled "Prime Wetlands, Nashua, New Hampshire" prepared for the Nashua Conservation Commission. R-90-84 defines primary wetlands as:
75
The Merrimack River and its wetlands
The Nashua River and its wetlands
Salmon Brook and its wetlands
Pennichuck Brook, Bowers Pond, Harris Pond, Holts Pond, Pennichuck Pond, Supply Pond and its wetlands
Lovewell's Pond and its wetlands
Horse Pond and its wetlands
Old Ridge Road wetland
Nashua Canal
Nashua Cove
Critical wetlands
Critical wetlands are the following water bodies and watercourses and their wetlands. Critical wetlands also include any perennial streams that are tributaries to prime wetlands.
40
Boire Brook
Mill Pond
Coburn Pond
Muddy Brook
Cold Brook
Old Maid's Brook
Colerain Brook
Round Pond
Hales Brook
Spectacle Brook
Harris Brook
Spit Brook
Hassells Brook
Trout Brook
Lincoln Brook
Sandy Pond
Lyle Reed Brook
Other wetlands over 9,000 square feet
Any wetland other than a primary or a critical wetland over 9,000 square feet in area
40
Other wetlands from 3,000 to 9,000 square feet and intermittent streams
Any wetland other than a primary or critical wetland between 3,000 and 9,000 square feet in area. Intermittent streams require a twenty-foot buffer from both banks, measured from top of bank. Intermittent streams are streams with a defined channel but that may not flow the entire year. Isolated man-made drainage ditches are not included.
20
Vernal pools
100-foot minimum buffer. Vernal pool boundaries to be determined by a certified wetlands scientist. Buffer boundary to be determined by a certified wetlands scientist or other licensed land surveyor.
100
The provisions of these wetlands regulations shall be administered and enforced by the Administrative Officer. Where the provisions of these regulations are superimposed over the zoning district, the more restrictive regulations apply. The Administrative Officer shall institute, or cause to be instituted, such actions necessary to ensure compliance with these provisions, and/or the conditions placed upon any required special exception permit or other approval. The Administrative Officer shall also have the authority to cause whatever actions are necessary at a site or location where a violation of this chapter has occurred to ensure that it is returned to its original quality and function, and the same cause of action shall be at no cost to the City and shall be assessed to the violator.
A. 
Applicability. The section applies to any activity proposed within a wetland or a wetland buffer, except for erosion control measures and the regular use, maintenance or repair of existing buildings, structures, or the improved portions of an existing developed site such as roads, parking lot or sidewalks. It includes any application for development approval, including any building permit applications; land use permit application; Zoning Board of Adjustment applications; Planning Board applications; Board of Health application, or any other any other land use requiring a permit or approval as required by and within the Nashua City Code.
B. 
Initiation. As part of the initiation of any application listed in Subsection A above, the Administrative Officer shall determine whether the land area in which the proposed use, development or activity lies is within a wetland or buffer area as described in § 190-112. If the Administrative Officer determines that the proposed use, development or activity is within a wetland or buffer area, the Administrative Officer shall notify the applicant in writing that the Conservation Commission must review a wetlands application. The Administrative Officer shall provide notification within two weeks after submittal of a complete application. If such notification is provided to the applicant, the applicant shall submit a Wetlands Application Review Form with the information required by § 190-284 of this chapter to the Administrative Officer. Upon receipt of such an application and payment of applicable fees, the Administrative Officer shall forward a copy of the application to the Conservation Commission.
C. 
Wetlands data.
(1) 
Primary or critical wetlands. Applications submitted for uses proposed within or adjacent to primary or critical wetlands shall be accompanied by sufficiently detailed information and plans. Such plans shall clearly show the extent of the wetland and buffer areas located on or immediately adjacent to the subject property, and the uses proposed to be located on the subject property. Primary wetlands must be delineated as shown on the Nashua Prime Wetlands Maps. In determining the sufficiency of the information to be provided, the applicant shall consult with the Administrative Officer regarding the nature of the proposed uses and their relations and proximity to any potentially affected wetlands located on or immediately adjacent to the subject property. The applicant shall also clearly note on the plan any and all sources of wetland delineation information used to determine the wetlands boundary and shall provide documentation regarding the status of any other permits required under local, state or federal laws.
(2) 
Other wetlands. For development or other regulated activity proposed on sites abutting other wetlands as defined in Table 112-1, the applicant shall be required to denote the boundary and methods used to locate it. The Administrative Officer may consult with the applicant regarding the application regulations.
D. 
Submittal procedures.
(1) 
The applicant shall review the Nashua Conservation Commission Wetland Review Process as set forth in § 190-284.
(2) 
The applicant shall provide the Conservation Commission and Administrative Officer with a completed wetlands application two weeks in advance of the Conservation Commission meeting at which the proposed project will be discussed.
(3) 
Upon receipt of the wetlands application by the Conservation Commission and Administrative Officer, the applicant may be asked to provide additional technical information.
(4) 
The applicant shall schedule a preliminary presentation with the Commission. At that time, the Conservation Commission may schedule a site walk. At the site walk, the Commission members may request additional information for the applicant to present at the next Conservation Commission meeting, such as a wetlands and buffer delineation and protection plan. The members may provide other informal guidance.
(5) 
The Conservation Commission may request a review of the project by planning staff prior to providing their recommendation. Sufficient time will be provided to allow the Conservation Commission to provide a recommendation on the project to the Administrative Officer.
E. 
Recommendation. The Conservation Commission shall consider the application at a public meeting and shall prepare a written recommendation as to whether the proposed development lies within an area subject to § 190-112, and whether the proposed development complies with this section. The recommendation shall be provided to the Zoning Board of Adjustment. In rendering its decision, the Zoning Board of Adjustment or Building Department Manager shall give due consideration to the recommendations of the Conservation Commission so as to avoid or minimize the detrimental impacts which the proposed use may have on the wetland or wetland buffer. Any amendments to a plan following a Conservation Commission decision but before the Zoning Board of Adjustment review shall be reviewed again by the Conservation Commission. Decisions rendered by the Zoning Board of Adjustment are final but subject to appeal as set forth in Article XIX.
F. 
Approval criteria. See §§ 190-284 and § 190-115 below.
G. 
Amendments. The applicant may modify the wetlands application at any time before the final recommendations of the Conservation Commission are made.
H. 
Scope of approval. The wetlands application shall be deemed a part of the underlying application for development approval and a condition of any permit or land use decision subject to this section.
I. 
Recording procedures. The wetlands application shall be recorded with the underlying application for development approval.
J. 
Exceptions. A property owner who intends to undertake routine annual maintenance that has been previously approved by the Conservation Commission is not required to return to the Conservation Commission or obtain a special exception.
A. 
Review for conformity.
(1) 
Uses proposed in any wetland or within the required buffer area shall be reviewed by the Conservation Commission for conformity with this section. A wetlands-related special exception is required prior to and in addition to other relevant approvals.
(2) 
For uses or activities proposed outside of and adjacent to any wetland or buffer area, the Administrative Officer shall review the proposal for consistency with this section to demonstrate that what is being proposed is reasonable or necessary, and can be implemented without undue harm to the wetland or buffer area being impacted. Upon receipt of a complete application, the Administrative Officer shall determine whether a special exception is required prior to other necessary reviews/approvals.
B. 
Wetland or buffer encroachments. For uses proposed to encroach into wetlands or required buffer areas, including but not necessarily limited to road and utility line crossings, water dependent uses (e.g., docks), bridges or other road and passive recreational facilities or activities, the Zoning Board of Adjustment shall find the following prior to approval:
(1) 
That the use or activity proposed and its attendant impacts cannot reasonably be avoided.
(2) 
That the least damaging route and methodology have been selected, and that which is being proposed is the best practicable alternative available.
(3) 
That reasonable and acceptable impact mitigation measures have been incorporated where necessary and appropriate to minimize wetland loss or degradation.[1]
[1]
Note: The removal of invasive species may be an appropriate mitigation technique. Invasive species are listed in the most recent State of New Hampshire Prohibited Invasive Species List.
(4) 
That the overall impact of encroaching into wetland or buffer areas is necessary for the productive use of adjoining buildable land and, as such nonencroachment, is outweighed by the benefits thereby derived.
(5) 
That no significant impact on the habitat of rare or endangered species or exemplary communities, as listed by the State of New Hampshire or federal government, will result.
(6) 
That the best available adequate erosion and sedimentation control methods are incorporated.[2]
[2]
Note: Some appropriate erosion control standards are: Stormwater Management and Erosion and Sediment Control Handbook for Urban and Developing Areas in New Hampshire, New Hampshire Department of Environmental Services, Rockingham County Conservation District, USDA Soil Conservation Service (August 1992), and Stormwater Management for Construction Activities, Environmental Protection Agency (September 1992).
(7) 
That the proposed activity or use shall not significantly impair wetland capacity to provide important wildlife and fishery functions, including habitat, food, shelter, breeding, migratory and over-wintering.
(8) 
That the project shall not impair the stability of a water body's bank.
(9) 
That the wetland and buffer function of hydrologic absorption capacity and storage shall not be impaired.
C. 
Uses adjacent to wetlands or buffer areas. Any use or activity proposed within 100 feet of a wetland shall be reviewed by the Administrative Officer for compliance with the following performance standards:
(1) 
That no significant impact on the habitat of rare or endangered species or exemplary communities, as listed by the State of New Hampshire or the Federal government, will result.
(2) 
That the filtration of stormwater runoff is adequately provided for and controlled both during and after construction.
(3) 
That the topography and required regrading of the subject property accounts for and adequately reflects the proximity of a nearby wetland area.
(4) 
All landscaping requirements and maintenance regiments for a project will ensure that fertilizer and chemical runoff shall not enter the wetland.
(5) 
For any wetland area utilized for water runoff, the applicant shall demonstrate that excess flow on wetlands shall not cause excessive ponding and retention, thereby causing environmental damage to existing flora or fauna.
(6) 
Where land is proposed to be subdivided, the applicant shall demonstrate that there is adequate nonwetland area to contain all proposed uses, structures, and utilities in accordance with these regulations.
D. 
Prohibited uses. No use or activity shall be located within 125 feet or sited in such a manner so as to pose a serious environmental hazard to a nearby wetland. Uses prohibited include, but are not limited to, septic systems, underground storage tanks not within approved enclosures, junkyards or salvage yards, or the uncontained or uncontrolled stockpiling of any material which may contaminate the wetland.
A. 
Applicability. The Nashua Conservation Commission may require wetland buffers to be marked in order to prevent future encroachment. This section applies to:
(1) 
Any development subject to an application for building permit, subdivision or site plan approval;
(2) 
Any development approved before the effective date of this section that is determined to be in violation of any wetland buffer required that existed at the time the development was approved; or
(3) 
Any activity within a wetland or wetland buffer that was undertaken without obtaining a required special exception.
B. 
Requirements. Wetlands (prime, critical, and other) shall be delineated by a State of New Hampshire certified wetland scientist. The wetland buffer shall be located and flagged by an engineer or surveyor. The markers shall follow the contour of the buffer, generally not more than 50 feet apart. The engineer or surveyor shall take all necessary precautions to ensure that said markers disturb no asbestos-fill sites. Where the buffer intersects the property line, markers should be placed on the property line. Markers should be placed along the buffer contour at the point closest to any adjacent structure. The requirements for placing markers are further described in the pamphlet "Requirements for Construction and Installation of Conservation Easement, Wetland Buffer, and Conservation Land Plaques."
A. 
Applicability. A tree that has been substantially damaged or unlawfully removed from a wetland buffer that is protected by City ordinances must be replaced with its equivalent replacement in trees. Replacement trees shall be a type of species having shade potential and other positive values at least equal to that of the tree that was removed and shall be a minimum of six feet in height when planted.
B. 
Definitions. As used in this article, the following terms shall have the meanings indicated:
DIAMETER AT BREAST HEIGHT (DBH)
The measurement of a tree's trunk diameter in inches at breast height 4 1/2 feet above ground level. For trees with less than 4 1/2 feet of clear trunk, the diameter shall be of the largest leader measured 4 1/2 feet above ground level. For multitrunk trees it shall be the sum of the diameter of the individual trunks measured 4 1/2 feet above ground level. If the DBH is not determinable because cut trees have been removed from the site, DBH shall be determined from the "DBH in Relation to Stump Diameter" tables found in the Forestry Handbook, 2nd ed., 1984, by the Society of American Foresters, edited by Karl Wenger, published by John Wiley & Sons Publishers.
EQUIVALENT REPLACEMENT
The replacement of a removed or damaged tree to compensate for that tree's removal or its damage with one tree the same diameter or a combination of smaller trees that will equal that removed tree's DBH as defined herein.
TREE
Any living, self-supporting woody perennial plant at maturity, which attains a trunk diameter of at least three inches or more when measured at a point 4 1/2 feet above ground level and which normally attains an overall height of at least 15 feet, usually with one main stem or trunk and many branches.
TREE-FOR-TREE REPLACEMENT
Replacing a removed tree with a tree or trees with a minimum of three inches in cumulative trunk diameter at breast height. The replacement species shall be native trees as defined in Trees and Shrubs in New Hampshire, A Guidebook for Natural Beauty Projects, by Cooperative Extension Service, University of New Hampshire, Durham, NH. Replacement species shall not include those species that are not recommended in the guidebook.
C. 
Replacement trees. A removed tree must be replaced with its equivalent replacement in trees.
D. 
Maintenance of replacement trees. The property owner must replace trees within 30 days from receipt of a written notice of violation for unlawful tree removal. The Administrative Officer may grant a time extension for tree replacement if the thirty-day requirement would mean that trees would be planted outside the appropriate planting season (April-June and September-November).
E. 
Financial security for tree replacement. A financial security shall be held by the City of Nashua for one year to ensure tree replacement in the event that tree replacement results in the death of any replacement trees. The security amount shall be assessed at three times the fair market value of the required replacement tree(s).
F. 
Landscape (tree replacement) plan. Prior to installation of the required replacement trees, a proposed landscape plan must be prepared by a professional landscape architect and approved by the Administrative Officer, who shall consult with the City's Conservation Commission. Replacement trees shall be true to the botanical names and standards of size, culture and quality for the highest grades and standards as sponsored by the American Association of Nurserymen, Inc., in the American Standard for Nursery Stock, latest edition.
G. 
Exemptions. During emergency conditions caused by a hurricane or other disaster, or to protect public safety, the Administrative Officer may suspend provisions of this section.
H. 
Penalties. The removal of each tree in a buffer zone shall constitute a separate zoning violation, punishable in a court of competent jurisdiction per RSA Chapter 676.