ARTICLE XV

FLOODPLAIN ORDINANCE

Adopted March 13, 1990

Certain areas of the Town of Wilmot, New Hampshire are subject to periodic flooding, causing serious damages to properties within these areas.  Relief is available in the form of flood insurance as authorized by the National Flood Insurance Act of 1968.  Therefore, the town of Wilmot, New Hampshire has chosen to become a participating community in the National Flood Insurance Program, and agrees to comply with the requirements of the National Flood Insurance Act of 1968 (P.L. 90-488, as amended) as detailed in this Floodplain Management Ordinance.

The ordinance establishes a permit system and review procedure for development activities in the designated flood hazard areas of the town of Wilmot, New Hampshire.

This ordinance, adopted pursuant to the authority of RSA 674:16, shall be known as the Town of Wilmot Floodplain Development Ordinance.  The regulations in this ordinance shall overlay and supplement the regulations in the Town of Wilmot Zoning Ordinance, and shall be considered part of the Zoning Ordinance for purposes of administration and appeals under state law.  If any provision of this ordinance differs or appears to conflict with any provision of the Zoning Ordinance or other ordinance or regulation, the provision imposing the greater restriction or more stringent standard shall be controlling.

The following regulations in this ordinance shall apply to all lands designated as special flood hazard areas by the Federal Emergency Management Agency (FEMA) in its Flood Insurance Rate Maps dated April 1, 1986 which are declared to be a part of this ordinance and are hereby incorporated by reference.

Section I: Definitions

The following definitions shall apply only to this Floodplain Development Ordinance, and shall not be affected by the provisions of any other ordinance of the Town of Wilmot.

Area of Special Flood Hazard

The land in the floodplain within the Town of Wilmot subject to a one-percent or greater possibility of flooding in any given year.  The area is designated on the FIRM as Zone A.

Base Flood

The flood having a one-percent possibility of being equaled or exceeded in any given year.

Basement

Any area of a building having a floor sub grade on all sides.

Building

See “Structure”

Development

Any man-made change to improved or unimproved real estate, including but no limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation, or drilling operation or storage of equipment or materials.

FEMA

The Federal Emergency Management Agency

Flood or Flooding

A general and temporary condition of partial or complete inundation of normally dry land areas from:

1. the overflow of inland or tidal waters, or
2. the unusual and rapid accumulation or runoff of surface waters from any source.

Flood Insurance Rate Map (FIRM)

An official map incorporated with this ordinance, on which FEMA delineated both the special flood hazard areas and the risk premium zones applicable to the Town of Wilmot.

Flood Insurance Study (FIS)

FIS means an examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e. mudflow) and/or flood-related erosion hazards.         

Floodplain or Flood-prone area

Any land area susceptible to being inundated by water from any source (see definition of “Flooding”).

Flood proofing

Any combination of structural and non-structural additions, changes or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitation facilities, structures and their contents.

Floodway 
See “Regulatory Floodway”

Functionally Dependent use

A use which cannot perform it intended purpose unless it is located or carried out in close proximity to water.  The term includes only docking and port facilities that are necessary for the loading/unloading of cargo or passengers, and ship building/repair facilities but does not include long-term storage or related manufacturing facilities.

Highest adjacent Grade

The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

Historic Structure

Any structure that is:

1. 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;
2. 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;
3. 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
4. Individually listed on a local inventory  of historic places in communities with historic preservation programs that have been certified either:

• • By an approved state program as determined by the Secretary of the Interior;
  • Directly by the Secretary of the Interior in states without approved programs.

Lowest Floor

The lowest floor of the lowest enclosed area (including basement).  An unfinished or flood resistant enclosure, usable solely for parking vehicles, building access or storage in an area other than a basement area is not considered a building’s lowest floor; provided, that such an enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of this ordinance.

Manufactured Home

A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities.  For floodplain management purposes the term “Manufactured Home” includes park trailers, travel trailers, and other similar vehicles placed on site for greater than 180 days.

Manufactured Home Park or Subdivision

A parcel (or contiguous parcels) of land divided into tow or more manufactured home lots for rent or sale.

Mean sea level

The National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum (NAVD) of 1988, or other datum, to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced.

New Construction

For the purposes of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures.  For floodplain management purposes, new construction means structures for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures.

100-year Flood
See “Base Flood”

Recreational Vehicle

A vehicle that is:

1. built on a single chassis;
2. 400 square feet or less when measured at the largest horizontal projection;
3. designed to be self-propelled or permanently tow able by a light duty truck; and
4. designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel or seasonal use (this definition applies only to the Floodplain Ordinance.

Regulatory Floodway

The channel of a river 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. 

Special Flood Hazard area 
See  “Area of Special Flood Hazard”

Structure

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.

Start of Construction

Includes substantial improvements, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement, or other improvement was within 180 days of the permit date.  The actual start means either the first placement of permanent construction of a structure on site, such as the pouring of slab or footings, the installation of piles , the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation.  Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or part of the main structure.

Substantial damage

Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

Substantial Improvement

Any combination of repairs, reconstruction, alteration, or improvements to a structure in which the cumulative cost equals or exceeds 50 percent of the market value of the structure.  The market value of the structure should equal:

1. the appraised value prior to the start of the initial repair or improvement, or
2. in the case of damage, the value of the structure prior to the damage occurring.

For the purposes of this definition, “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.  This term includes structures which have incurred substantial damage, regardless of actual repair work performed.  The term does not, however, include any project for improvement of a structure required to comply with existing health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions or any alterations of a “historic structure”, provided that the alteration will not preclude the structure’s continued designation as a “historic structure”.

Violation

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 under Section V or Section VIII (2)(b) of this ordinance is presumed to be in violation until such time as that documentation is provided.

Water surface elevation

The height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum (NAVD) of 1988, (or other datum, where specified) of floods of various magnitudes and frequencies in the floodplains).

Section II
Permit

All proposed development in any special flood hazard area shall require a permit.

Section III
Proposed Building Sites

The Board of Selectmen shall review all certificate of zoning compliance applications for new construction or substantial improvements to determine whether proposed building sites will be reasonably safe from flooding.  If a proposed building site is located in a special flood hazard area, all new construction or substantial improvements shall:

1. be designed (or modified) and adequately anchored to prevent floatation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy,
2. be constructed with materials resistant to flood damage,
3. be constructed by methods and practices that minimize flood damages,
4. be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment, and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

Section IV
Sewage

Where new or replacement water and sewer systems (including on site systems) are proposed in a special flood hazard area the applicant shall provide the Board of Selectmen with assurance that these systems will be designed to minimize or eliminate infiltration of flood waters, and on-site waste disposal systems will be located to avoid impairment to them or contamination from them during periods of flooding.

Section V
Required Documents

For all new or substantially improved structures located in special flood hazard areas, the applicant shall furnish the following information to the Board of Selectmen:

1. the as-built elevation (in relation to NGVD) of the lowest floor (including basement) and include whether or not such structures contain a basement.
2. If the structure has been flood proofed, the as-built elevation (in relation to NGVD) to which the structure was flood proofed.
3. Any certification of flood proofing.

The Board of Selectmen shall maintain for public inspection, and shall furnish such information upon request.

Section VI
Necessary Permits

The Board of Selectmen shall not grant a building permit until the applicant certifies that all necessary permits have been received from those governmental agencies form which approval is required by federal or state law, including Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C 1334.

Section VII
Altered Watercourses

1. In riverine situations, prior to the alteration or relocation of a watercourse, the applicant for such authorization shall notify the Wetlands Bureau of the New Hampshire Department of Environmental Services and submit copies of such notification to the Board of Selectmen, in addition to the copies required by RSA 482-A:3.  Further, the applicant shall be required to submit copies of said notification to those adjacent communities as determined by the Board of Selectmen, including notice of all scheduled hearings before the Wetland Bureau.
2. The applicant shall submit to the Board of Selectmen certification provided by the registered professional engineer, assuring that the flood carrying capacity of an altered or relocated watercourse can and will be maintained.
3. The Board of Selectmen shall obtain, review, and reasonably utilize any floodway data available from Federal, State, or other sources as criteria for requiring that all development location in Zone A meet the following requirement: No encroachments, including fill, new construction, substantial improvements, and other development are allowed within the floodway that would result in any increase in flood levels within the community during the base flood discharge.

Section VIII
Engineering Specifications

1. In Zone A the zoning compliance officer shall obtain, review, and reasonably utilize any 100-year flood elevation data available from any federal, state or other source including data submitted for development proposals submitted to the community (i.e. subdivisions, site plan approvals).
2. The Board of Selectmen’s 100-year flood elevation determination will be used as criteria for requiring in Zone A that:
   
   1. All new construction or substantial improvement of residential structures have the lowest floor (including basement) elevated to or above the 100-year flood elevation;
   2. That all new construction or substantial improvements of non-residential structures have the lowest floor (including basement) elevated to or above the 100-year flood level; or together with attendant utility and sanitary facilities shall:

• • • Be flood proofed so that below the 100-year flood elevation the structure is watertight with walls substantially impermeable to the passage of water;
    • Have structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy; and
    • Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of this section;

2. 3. All manufactured homes to be placed or substantially improved within special flood hazard areas shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the 100-year flood elevation; and be securely anchored to resist floatation, collapse. Or lateral movement.  Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors;
   4. For all new construction and substantial improvements, fully enclosed areas below the lowest floor that are subject to flooding are permitted provided they meet the following requirements:

• • • The enclosed area is unfinished or flood resistant, usable solely for the parking of vehicles, building access or storage;
    • The area is not a basement;
    • Shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater.  Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria: A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.  The bottom of all openings shall be no higher than one foot above grade.  Openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwater.

1. 5. All recreational vehicles placed on sites within Zone A shall either;

• • • Be on the site for fewer than 180 consecutive days;
    • Be fully licensed and ready for highway use; or
    • Meet all standards of Section II of this ordinance and the anchoring requirements for “manufactured homes” in Section VIII 2 (c) of this ordinance.

Section IX
Variances and Appeals

1. Any order, requirement, decision or determination of the Board of Selectmen made under this ordinance may be appealed to the Zoning Board of Adjustment as set forth in RSA 676:5.
2. If the applicant, upon appeal, requests a variance as authorized by RSA 674:33, I(b), the applicant shall have the burden of showing in addition to the usual variance standards under state law:

• •  That the variance will not result in increased flood heights, additional threats to public safety, or extraordinary public expense.
  • That if the requested variance is for activity within a designated regulatory floodway, no increase in flood levels during the base flood discharge will result; and
  • That the variance is the minimum necessary, considering the flood hazard, to afford relief.

      3. The Zoning Board of Adjustment shall notify the applicant in writing that:

• • The issuance of a variance to construct below the base flood level will result in increase premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage and
  • Such construction below the base flood level increases risks to life and property.
  • Such notification shall be maintained with a record of all variance actions.

       4.  The community shall

• 
  
  • Maintain a record of all variance actions, including their justification for their issuance, and
  • Report such variances issued in its annual or biennial report submitted to FEMA’s Federal Insurance Administrator