Chapter 15.10
FLOOD HAZARD AREAS
Sections:
15.10.020 General provisions – Lands to which this chapter applies.
15.10.030 General provisions – Basis for establishing the areas of special flood hazard.
15.10.040 General provisions – Compliance.
15.10.050 General provisions – Abrogation and greater restrictions.
15.10.060 General provisions – Interpretation.
15.10.070 General provisions – Warning and disclaimer of liability.
15.10.080 Administration – Establishment of development permit.
15.10.090 Administration – Designation of the building inspector.
15.10.100 Administration – Duties and responsibilities of the building inspector.
15.10.110 Administration – Variance procedure.
15.10.120 Provisions for flood hazard reduction – General standards.
15.10.130 Provisions for flood hazard reduction – Specific standards.
15.10.140 Provisions for flood hazard reduction – Specific standards – Floodways.
15.10.010 Definitions.
Unless specifically defined below, words or phrases used in this chapter shall be interpreted so as to give them the meaning they have in common usage and to give this chapter its most reasonable application.
“Appeal” means a request for a review of the building inspector’s interpretation of any provisions of this chapter or a request for a variance.
“Area of special flood hazard” means the land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year.
“Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year.
“Development” means any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations located within the area of the special flood hazard.
“Existing manufactured home park or subdivision” means a manufactured home park for which the construction of facilities for servicing the lot on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, either final site grading or the pouring of concrete pads, and the construction of streets) are completed before the effective date of the ordinance codified in this section.
“Expansion to an existing manufactured home park or subdivision” means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, either final site grading or pouring of concrete pads, or the construction of streets).
“Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from:
(1) The overflow of inland or tidal waters; and/or
(2) The unusual and rapid accumulation or runoff of surface waters from any source.
“Flood Insurance Rate Map (FIRM)” means the official map on which the Federal Emergency Management Agency has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.
“Flood Insurance Study” means the official report provided by the Federal Emergency Management Agency that includes flood profiles, the Flood Boundary-Floodway Map and the water surface elevation of the base flood.
“Floodway” means 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 one foot.
“Lowest floor” means the lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building’s lowest floor; provided, that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of this chapter.
“Manufactured home” means 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 attached to the required utilities. The term “manufactured home” does not include a “recreational vehicle.”
“New manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after the effective date of floodplain management regulations adopted by a community.
“New construction” means structures for which the “start of construction” commenced on or after the effective date of the ordinance codified in this section.
“Recreational vehicle” means a vehicle which is:
(1) Built on a single chassis;
(2) Four hundred square feet or less when measured at the largest horizontal projections;
(3) Designed to be self-propelled or permanently towable 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.
“Start of construction” includes substantial improvement, 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 the first placement of permanent construction of a structure on a 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 not part of the main structure.
“Structure” means a walled and roofed building or manufactured home that is principally above ground.
“Substantial damage” means 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” means any reconstruction, rehabilitation, addition or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the “start of construction” of the improvement. This term includes structures which have incurred “substantial damage,” regardless of the actual repair work performed. The term does not, however, include either:
(1) Any project for improvement of a structure to correct existing violation of state or local health, sanitary or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or
(2) Any alteration of a “historic structure”; provided, that the structure’s continued designation as a “historic structure.”
“Variance” means a grant of relief from the requirements of this chapter which permits construction in a manner that would otherwise be prohibited by this chapter. [Ord. 592, 1989. 1996 Code § 8A-l.]
15.10.020 General provisions – Lands to which this chapter applies.
This chapter shall apply to all areas of special flood hazard within the jurisdiction of the town of Wheatland. [1996 Code § 8A-2.]
15.10.030 General provisions – Basis for establishing the areas of special flood hazard.
The areas of special flood hazard identified by the Federal Emergency Management Agency in a scientific and engineering report entitled, “The Flood Insurance Study for the town of Wheatland,” dated October 1978, with an accompanying Flood Insurance Rate Map (FIRM), are hereby adopted by reference and declared to be a part of this chapter. The Flood Insurance Study and FIRM are on file at the office of the building inspector located in the City Hall, Wheatland, Wyoming. [1996 Code § 8A-3.]
15.10.040 General provisions – Compliance.
No structure or land shall hereafter be constructed, located, extended, converted or altered without full compliance with the terms of this chapter and other applicable regulations. [1996 Code § 8A-4.]
15.10.050 General provisions – Abrogation and greater restrictions.
This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another chapter, ordinance, easement, covenant or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. [1996 Code § 8A-5.]
15.10.060 General provisions – Interpretation.
In the interpretation and application of this chapter, all provisions shall be:
(a) Considered as minimum requirements;
(b) Liberally construed in favor of the governing body; and
(c) Deemed neither to limit nor repeal any other powers granted under state statutes. [1996 Code § 8A-6.]
15.10.070 General provisions – Warning and disclaimer of liability.
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not imply that land outside the areas of special flood hazard or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the town of Wheatland, any officer or employee thereof, or the Federal Emergency Management Agency for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder. [1996 Code § 8A-7.]
15.10.080 Administration – Establishment of development permit.
A development permit shall be obtained before construction or development begins within any area of special flood hazard established in WMC 15.10.030. Application for a development permit shall be made on forms furnished by the building inspector and may include, but not be limited to:
Plans in duplicate drawn to scale showing the nature, location, dimensions and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing. Specifically, the following information is required:
(a) Elevation in relation to mean sea level of the lowest floor (including basement) of all structures;
(b) Elevation in relation to mean sea level to which any structure has been floodproofed;
(c) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in WMC 15.10.130(b); and
(d) Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. [1996 Code § 8A-8.]
15.10.090 Administration – Designation of the building inspector.
The building inspector is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. [1996 Code § 8A-9.]
15.10.100 Administration – Duties and responsibilities of the building inspector.
(a) Duties of the building inspector shall include, but not be limited to:
(1) Review all development permits to determine that the permit requirements of this chapter have been satisfied.
(2) Review all development permits to determine that all necessary permits have been obtained from federal, state or local governmental agencies from which prior approval is required.
(3) Review all development permits to determine if the proposed development is located in the floodway. If located in the floodway, assure that the encroachment provisions of WMC 15.10.140(a) are met.
(b) Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with WMC 15.10.030, the building inspector shall obtain, review and reasonably utilize any base flood elevation and floodway data available from any federal, state or other source as criteria for requiring that new construction, substantial improvements or other development in Zone A are administered in accordance with WMC 15.10.130.
(c) Information to Be Obtained and Maintained.
(1) Obtain and record the actual elevation (in relation to mean sea level) of the lowest floor (including basement) of all new or substantially improved structures, and whether or not the structure contains a basement.
(2) For all new or substantially improved floodproofed structures:
a. Verify and record the actual elevation (in relation to mean sea level) to which the structure has been floodproofed.
b. Maintain the floodproofing certifications required in WMC 15.10.080(c).
c. Maintain for public inspection all records pertaining to the provisions of this chapter.
(d) Alteration of Watercourses.
(1) Notify adjacent communities and the appropriate state and federal agencies prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Emergency Management Agency.
(2) Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood-carrying capacity is not diminished.
(e) Interpretation of FIRM Boundaries. Make interpretations, where needed, as to the exact location of the boundaries of the areas of special flood hazard (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in WMC 15.10.110. [1996 Code § 8A-10.]
15.10.110 Administration – Variance procedure.
(a) Appeal Board.
(1) The board of adjustment, as established by the town of Wheatland, shall hear and decide appeals and request for variances from the requirements of this chapter.
(2) The board of adjustment shall hear and decide appeals when it is alleged there is an error in any requirement, decision or determination made by the building inspector in the enforcement or administration of this chapter.
(3) Those aggrieved by the decision of the board of adjustment or any taxpayer may appeal such decisions to the District Court, Eighth Judicial, Platte County, Wyoming, as provided by state law.
(4) In passing upon such applications, the board of adjustment shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and:
a. The danger that materials may be swept onto other lands to the injury of others;
b. The danger to life and property due to flooding or erosion damages;
c. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owners;
d. The importance of the services provided by the proposed facility to the community;
e. The necessity to the facility of a waterfront location, where applicable;
f. The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;
g. The compatibility of the proposed use with the existing and anticipated development;
h. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;
i. The safety of access to the property in times of flood for ordinary and emergency vehicles;
j. The expected heights, velocity, duration, rate of rise and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site; and
k. The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, and water systems, streets and bridges.
(5) Upon consideration of the factors of subsection (a)(4) of this section and the purposes of this chapter, the board of adjustment may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.
(6) The building inspector shall maintain the records of all appeal actions, including technical information, and report any variances to the Federal Emergency Management Agency.
(b) Conditions for Variances.
(1) Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base level, providing subsections (a)(4)(a) through (k) of this section have been fully considered. As the lot size increases beyond the one-half acre, the technical justifications required for issuing the variance increases.
(2) Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places without regard to the procedures set forth in the remainder of this section.
(3) Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.
(4) Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
(5) Variances shall only be issued upon:
a. A showing of good and sufficient cause;
b. A determination that failure to grant the variance would result in exceptional hardship to the applicant; and
c. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public as identified in subsection (a)(4) of this section or conflict with existing local laws or chapters.
(6) Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk from the reduced lowest floor elevation. [1996 Code § 8A-11.]
15.10.120 Provisions for flood hazard reduction – General standards.
In all areas of special flood hazards, the following standards are required:
(a) Anchoring.
(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure and capable of resisting the hydrostatic and hydrodynamic loads.
(2) All manufactured homes must be elevated and anchored to resist flotation, collapse or lateral movement and capable of resisting the hydrostatic and hydrodynamic loads. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is an addition to applicable state and local anchoring requirements for resisting wind forces. Specific requirements may be:
a. Over-the-top ties be provided at each of the four corners of the manufactured home, with two additional ties per side at intermediate locations, with manufactured homes less than 50 feet long requiring one additional tie per side;
b. Frame ties be provided at each corner of the home with five additional ties per side at intermediate points, with manufactured homes less than 50 feet long requiring four additional ties per side;
c. All components of the anchoring system be capable of carrying a force of 4,800 pounds; and
d. Any additions to the manufactured home be similarly anchored.
(b) Construction Materials and Methods.
(1) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
(2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
(3) All new construction and substantial improvements shall 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.
(c) Utilities.
(1) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;
(2) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters; and
(3) On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
(d) Subdivision Proposals.
(1) All subdivision proposals shall be consistent with the need to minimize flood damage;
(2) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage;
(3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and
(4) Base flood elevation data shall be provided for subdivision proposals and other proposed development which contain at least 50 lots or four acres (whichever is less). [1996 Code § 8A-12.]
15.10.130 Provisions for flood hazard reduction – Specific standards.
In all areas of special flood hazards where base flood elevation data has been provided as set forth in WMC 15.10.030, Basis for establishing the areas of special flood hazard, or WMC 15.10.100(b), Use of Other Base Flood Data, the following provisions are required:
(a) Residential Construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement) elevated to or above the base flood elevation.
(b) Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor (including basement) elevated to the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:
(1) Be floodproofed so that below the base flood elevation the structure is watertight with walls substantially impermeable to the passage of water;
(2) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(3) 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 subsection. Such certifications shall be provided to the official as set forth in WMC 15.10.100(c)(2).
(c) Manufactured homes to be placed on a single lot or in a new or expansion to an existing manufactured home park or subdivision or in an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as a result of a flood:
(1) It is required that manufactured homes that are placed or substantially improved within Zones A1-30, AH and AE on the community’s FIRM on sites:
a. Outside of a manufactured home park or subdivision,
b. In a new manufactured home park or subdivision,
c. In an expansion to an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as the result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(d) Manufactured homes to be placed in an existing manufactured home park or subdivision in which a manufactured home has not incurred substantial damage as a result of a flood:
(1) It is required that manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1-30, AH, and AE on the community’s FIRM that are not subject to the provision of subsection (c) of this section be elevated so that either:
a. The lowest floor of the manufactured home is at or above the base flood elevation, or
b. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and is securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. [1996 Code § 8A-13.]
15.10.140 Provisions for flood hazard reduction – Specific standards – Floodways.
Located within areas of special flood hazard established in WMC 15.10.030 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles and erosion potential, the following provisions apply:
(a) Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer or architect is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
(b) If subsection (a) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section, provisions for flood hazard reduction. [1996 Code § 8A-14.]
Editor’s Note: Ordinance No. 600, passed on third and final reading August 13, 1990, which made minor amendments to Ordinance No. 592, passed on third and final reading on May 22, 1989. Ordinance No. 592 repealed Ordinance No. 495, which was set forth in Chapter 8(a) of the Wheatland Town Code supplemented in 8/84.