§ 13.05.010. Floodplain regulations.  


Latest version.
  • (a)

    Statutory authorization, findings of fact, purpose and objectives.

    (1)

    Statutory authorization. The legislature of the State has, in Title 29, Article 20, C.R.S., delegated the responsibility to local government units to adopt ordinances containing regulations designed to minimize flood losses and promote the public health, safety and general welfare of its citizenry. Therefore, the Town Council does ordain as follows:

    (2)

    Findings of fact.

    a.

    The flood hazard areas of the Town are subject to periodic inundation which can result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare.

    b.

    These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazard which increase flood heights and velocities, and when inadequately anchored, damage uses in other areas. Uses that are inadequately floodproofed, elevated or otherwise protected from flood damage also contribute to the flood loss.

    (3)

    Statement of purpose. It is the purpose of this Section to promote the public health, safety and general welfare, and to minimize public and private losses due to flood conditions to specific areas by provisions designed:

    a.

    To protect human life and health;

    b.

    To minimize expenditure of public money for costly flood control projects;

    c.

    To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

    d.

    To minimize prolonged business interruptions;

    e.

    To minimize damage to critical facilities, public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in areas of special flood hazard;

    f.

    To help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future flood blight areas;

    g.

    To ensure that potential buyers are notified that property is in an area of special flood hazard; and

    h.

    To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.

    (4)

    Methods of reducing flood losses. In order to accomplish its purposes, this Section includes methods and provisions for:

    a.

    Restricting or prohibiting uses which are dangerous to health, safety and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;

    b.

    Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;

    c.

    Controlling the alteration of natural floodplains, stream channels and natural protective barriers, which help accommodate or channel floodwaters;

    d.

    Controlling, filling, grading, dredging and other development which may increase flood damage; and

    e.

    Preventing or regulating the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards in other areas.

    (b)

    Definitions. Unless specifically defined below, words or phrases used in this Section shall be interpreted so as to give them the meaning they have in common usage and to give this Section its most reasonable application.

    Appeal means a request for a review of the Floodplain Administrator's interpretation of any provisions of this Section or a request for a variance.

    Area of special flood hazard means the land in the floodplain 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. The terms one-hundred-year flood (100-year flood) and one-percent-chance flood are synonymous with the term base flood. The term does not imply that the flood will necessarily happen once every one hundred (100) years.

    Base flood elevation means the elevation shown on a FEMA Flood Insurance Rate Map for Zones AE, AH, A1-A30, AR, AR/A, AR/AE, AR/A1-A30, AR/AH, AR/AO, V1-V30 and VE that indicates the water surface elevation resulting from a flood that has a one-percent chance of equaling or exceeding that level in any given year.

    Basement means any area of a building having its floor sub-grade (below ground level) on all sides.

    Channel means the physical confine of a stream or waterway consisting of a bed and stream banks, existing in a variety of geometrics.

    Channelization means the artificial creation, enlargement or realignment of a stream channel.

    Conditional Letter of Map Revision (CLOMR) means FEMA's comment on a proposed project, which does not revise an effective floodplain map, that would, upon construction, affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodplain.

    Critical facility or critical facilities means a structure or related infrastructure, but not the land on which it is situated, that, if flooded, may result in significant hazards to public health and safety or interrupt essential services and operations for the community at any time before, during and after a flood.

    Development means any man-made 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 or storage of equipment or materials located within the area of special flood hazard.

    Digital Flood Insurance Rate Map (DFRIM) means FEMA's digital floodplain map that serves as the regulatory floodplain map for insurance and floodplain management purposes.

    Elevated building means a nonbasement building: (i) built, in the case of a building in Zones A1-A30, AE, A, A99, B, C, X and D, to have the top of the elevated flood above the ground level by means of pilings, columns (posts and piers) or shear walls parallel to the flow of the water; and (ii) adequately anchored so as not to impair the structural integrity of the building during a flood of up to the magnitude of the base flood. In the case of Zones A1-A30, AE, A, A99, AO, AH, B, C, X and D, elevated building also includes a building elevated by means of fill or solid foundation perimeter walls with openings sufficient to facilitate the unimpeded movement of floodwaters.

    Existing manufactured home park or subdivision means a manufactured home park 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) are completed before the effective date of the ordinance codified herein.

    Expansion to 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, the construction of streets and either final site grading or the pouring of concrete pads).

    FEMA means the Federal Emergency Management Agency, the agency responsible for administering the National Flood Insurance Program.

    Flood or flooding means a general and temporary condition of partial or complete inundation of normally dry land areas from:

    a.

    The overflow of water from channels and reservoir spillways; and/or

    b.

    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 hazard and the risk premium zones.

    Flood Insurance Study means the official report provided by the Federal Emergency Management Agency that includes flood profiles, the Flood Insurance Rate Map and the water surface elevation of the base flood.

    Floodplain or flood-prone area means the area of land that could be inundated as a result of a flood.

    Floodplain Administrator means the community official designated by title to administer and enforce the floodplain management regulations.

    Floodplain development permit means a permit required before construction or development begins within any special flood hazard area (SFHA). If FEMA has not defined the SFHA within a community, the community shall require permits for all proposed construction or other development in the community, including the placement of manufactured homes, so that it may determine whether such construction or other development is proposed within flood-prone areas. Permits are required to ensure that proposed development projects meet the requirements of the NFIP and this Section.

    Floodproofing means any combination of structural and/or nonstructural additions, changes or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.

    Floodway (regulatory 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-half (½) foot (six [6] inches).

    Freeboard means the vertical distance in feet above the predicted water surface elevation intended to provide a margin of safety to compensate for unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood, such as debris blockage of bridge openings and the increased runoff due to urbanization of a watershed.

    Hydraulic analysis means the determination of flood elevations and velocities for various probabilities based on a scientific analysis of the movement and behavior of floodwaters in channels and overbank areas.

    Hydrologic analysis means the computation of the peak rate of flow, or discharge in cubic feet per second, for various selected probabilities for streams, channels or watersheds based on scientific analysis of the physical process.

    Letter of Map Revision (LOMR) means FEMA's official revision of an effective Flood Insurance Rate Map (FIRM) or Flood Boundary and Floodway Map (FBFM), or both. LOMRs are generally based on the implementation of physical measures that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective base flood elevations (BFEs) or the special flood hazard area (SFHA).

    Letter of Map Revision Based on Fill (LOMR-F) means FEMA's modification of the special flood hazard area (SFHA) shown on the Flood Insurance Rate Map (FIRM) based on the placement of fill outside the existing regulatory floodway.

    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 Section.

    Manufactured home means a structure, transportable in one (1) or more sections, which is built on a permanent chassis and is attached to the required utilities. The term manufactured home does not include a recreational vehicle.

    Mean sea level means the North American Vertical Datum (NAVD) of 1988 or other datum to which base flood elevations shown on a community's flood insurance map are referenced.

    National Flood Insurance Program (NFIP) means FEMA's program of flood insurance coverage and floodplain management administered in conjunction with the Robert T. Stafford Relief and Emergency Assistance Act. The NFIP has applicable federal regulations promulgated in Title 44 of the Code of Federal Regulations. The U.S. Congress established the NFIP with the passage of the National Flood Insurance Act of 1968.

    New construction means structures for which the start of construction commenced on or after the effective date of the original ordinance, and includes any subsequent improvements to such structures.

    New manufactured home park or subdivision means a manufactured home park or subdivision for which the construction or 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 those floodplain management regulations.

    No-rise certification means a record of the results of an engineering analysis conducted to determine whether a project will increase flood heights in a floodway. A no-rise certification must be supported by technical data and signed by a registered Colorado professional engineer.

    Physical map revision (PMR) means FEMA's action whereby one (1) or more map panels are physically revised and republished. A PMR is used to change flood risk zones, floodplain and/or floodway delineations, flood elevations and/or planimetric features.

    Recreational vehicle means a vehicle which is: (1) built on a single chassis; (2) four hundred (400) 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 that the actual start of construction, repair, reconstruction, placement or other improvement was within one hundred eighty (180) days of the permit date. The actual start means the first placement of permanent construction or a structure on a site, such as the pouring of slabs 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 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. 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.

    Structure means a walled and roofed building or manufactured home that is principally above ground.

    Structure 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 fifty percent (50%) 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:

    a.

    Any project for improvement of a structure to correct existing violations 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

    b.

    Any alteration of an "historic structure," provided that the alteration will not preclude the structure's continued designation as an "historic structure."

    Substantial damage means flood-related damage that equals or exceeds fifty percent (50%) of the value of the building. The value of the structure shall be determined by the local jurisdiction having land use authority in the area of interest.

    Substantial improvement means any reconstruction, rehabilitation, addition or other improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the start of construction of the improvement. The value of the structure shall be determined by the local jurisdiction having land use authority in the area of interest. This includes structures which have incurred substantial damage , regardless of the actual repair work performed.

    Variance means a grant of relief from the requirements of this Section which permits construction in a manner that would otherwise be prohibited by this Section.

    (c)

    General provisions.

    (1)

    Lands to which this Section applies. This Section shall apply to all areas of special flood hazard and areas removed from the floodplain by the issuance of a FEMA Letter of Map Revision Based on Fill (LOMR-F) within the jurisdiction of the Town.

    (2)

    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 Douglas County, Colorado, and Incorporated Areas , dated March 16, 2016, including any subsequent amendments made by the Town, with an accompanying Flood Insurance Rate Map (FIRM), as it may subsequently be amended, which report is hereby incorporated herein by this reference and declared to be a part of this Section. The Flood Insurance Study (FIS), DFIRMs and FIRMs are on file at the Department of Engineering, 20120 East Mainstreet in the Town.

    (3)

    Compliance. No structure or land shall hereafter be constructed, located, extended, converted or altered without full compliance with the terms of this Section and other applicable regulations. These regulations meet the minimum requirements as set forth by the Colorado Water Conservation Board and the National Flood Insurance Program.

    (4)

    Abrogation and greater restrictions. This Section is not intended to repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this Section and another ordinance, easement, covenant or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

    (5)

    Interpretation. In the interpretation and application of this Section, 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.

    (6)

    Warning and disclaimer of liability. The degree of flood protection required by this Section 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 man-made or natural causes. This Section 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 Section shall not create liability on the part of the Town, any officer or employee thereof or the Federal Emergency Management Agency for any flood damages that result from reliance on this Section or any administrative decision lawfully made thereunder.

    (d)

    Administration.

    (1)

    Establishment of floodplain development permit.

    a.

    A floodplain development permit shall be obtained before construction or development begins within any area of special flood hazard established in Paragraph (c)(2) above.

    b.

    Application for a floodplain development permit shall be made on forms furnished by the Floodplain Administrator 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:

    1.

    Elevation, in relation to mean sea level, of the lowest floor (including basement) of all structures;

    2.

    Elevation, in relation to mean sea level, to which any structure has been floodproofed;

    3.

    Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in Subparagraph (e)(2)b. below; and

    4.

    Description of the extent to which any watercourse will be altered or relocated as a result of proposed development and supporting hydraulic and hydrologic analysis, if appropriate.

    (2)

    Designation of the Floodplain Administrator. The Director of Engineering is hereby appointed to administer and implement this Section by granting or denying floodplain development permit applications in accordance with its provisions and other appropriate sections of 44 C.F.R. (National Flood Insurance Program Regulations) pertaining to floodplain management. The Director of Engineering may assign a designee to act as the Floodplain Administrator.

    (3)

    Duties and responsibilities of the Floodplain Administrator. Duties of the Floodplain Administrator shall include, but not be limited to:

    a.

    Permit review.

    1.

    Review all development permits to determine that the permit requirements of this Section 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 Subparagraph (e)(3)a. below are met.

    b.

    Use of other base flood data. When base flood elevation data has not been provided in accordance with Paragraph (c)(2) above, the Floodplain Administrator 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 area is administered in accordance with Paragraph (e)(2) below.

    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 certification required in Subparagraph (1)b.3. above.

    3.

    Maintain for public inspection all records pertaining to the provisions of this Section.

    d.

    Alteration of watercourses.

    1.

    Notify adjacent communities and the Urban Drainage and Flood Control District and/or the Colorado Water Conservation Board 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 Paragraph (4) below.

    (4)

    Variance procedure.

    a.

    Appeal Board.

    1.

    The Town Council, upon recommendation by the Planning Commission, as established by the Town, shall hear and decide appeals and requests for variances from the requirements of this Section.

    2.

    The Planning Commission and Town Council shall hear and decide appeals when it is alleged there is an error in any requirement, decision or determination made by the Floodplain Administrator in the enforcement or administration of this Section.

    3.

    Those aggrieved by the decision of the Town Council, or any taxpayer, may appeal such decisions to the District Court of the County, as provided in Section 31-23-201, C.R.S.

    4.

    In passing upon such applications, the Town Council shall consider all technical evaluations, all relevant factors, standards specified in other subsections of this Section; 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 damage;

    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 floodwaters 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 above factors of this Paragraph and the purposes of this Section, the Town Council may attach such conditions to the granting of variances as it deems necessary to further the purposes of this Section.

    6.

    The Floodplain Administrator 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 (½) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, provided that items in Subparagraph a.4. above have been fully considered. As the lot size increases beyond the one-half (½) acre, the technical justifications required for issuing the variance increase.

    2.

    Variances may be issued for the repair or rehabilitation of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as an historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure.

    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 expenses, create nuisances, cause fraud on or victimization of the public as identified in Subparagraph a.4. above or conflict with existing local laws or ordinances.

    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.

    (5)

    Properties removed from the floodplain by fill.

    a.

    A floodplain development permit shall not be issued for the construction of a new structure or addition to an existing structure on a property removed from the floodplain by the issuance of a FEMA letter of map revision based on fill (LOMR-F), unless such new structure or addition complies with the following:

    1.

    Residential construction. The lowest floor (including basement), electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities (including ductwork) must be elevated to two (2) feet above the base flood elevation that existed prior to the placement of fill.

    2.

    Nonresidential construction. The lowest floor (including basement), electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities (including ductwork) must be elevated to two (2) feet above the base flood elevation that existed prior to the placement of fill or, together with attendant utility and sanitary facilities, be designed so that the structure or addition is watertight to at least two (2) feet above the base flood level that existed prior to the placement of fill with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads or effects of buoyancy.

    (e)

    Provisions for flood hazard reduction.

    (1)

    General standards. In all areas of special flood hazard, 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 in 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 (4) corners of the manufactured home, with two (2) additional ties per side at intermediate locations, with manufactured homes less than fifty (50) feet long requiring one (1) additional tie per side;

    b)

    Frame ties be provided at each corner of the home with five (5) additional ties per side at intermediate points, with manufactured homes less than fifty (50) feet long requiring four (4) additional ties per side;

    c)

    All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds; and

    d)

    Any additions to the manufactured home be similarly anchored.

    b.

    Construction materials and methods.

    1.

    All new planned developments, subdivisions, site plans and building permits for new buildings shall preclude any development within a designated one-hundred-year floodplain, with the exception of necessary roads, utilities, trails and other facilities found to be acceptable to the Planning Commission and the Town Council. Buildable lots may be partially located within a one-hundred-year floodplain provided that the developer demonstrates that a buildable envelope, suitable in area and dimensions, is located entirely outside of the floodplain.

    2.

    All substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

    3.

    All substantial improvements shall be constructed using methods and practices that minimize flood damage.

    4.

    All 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 floodwaters into the system;

    2.

    New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters; 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 fifty (50) lots or five (5) acres (whichever is less).

    (2)

    Specific standards. In all areas of special flood hazard where base flood elevation data has been provided as set forth in Paragraph (c)(2) or Subparagraph (d)(3)b. above, the following provisions are required:

    a.

    Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement), electrical, heating, ventilation, plumbing and air conditioning equipment elevated, at a minimum, to two (2) feet 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 two (2) feet above the base flood elevation or, together with attendant utility and sanitary facilities, shall:

    1.

    Be floodproofed so that below two (2) feet above 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 Paragraph. Such certifications shall be provided to the Floodplain Administrator as set forth in Subparagraph (d)(3)c.2. above.

    c.

    Critical facilities. All new and substantially changed critical facilities and new additions to critical facilities, shall have a minimum freeboard of two (2) feet above the 100-year-flood elevation (base flood elevation).

    d.

    Openings in enclosures below the lowest floor. For all new construction and substantial improvements, fully enclosed areas below the lowest floor that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. 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:

    1.

    A minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding shall be provided;

    2.

    The bottom of all openings shall be no higher than one (1) foot above grade;

    3.

    Openings may be equipped with screens, louvers or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

    e.

    Manufactured homes.

    1.

    Manufactured homes shall be anchored in accordance with Subparagraph (1)a.2. above.

    2.

    All manufactured homes or those to be substantially improved shall conform to the following requirements:

    a)

    Require that manufactured homes that are placed or substantially improved on a site (i) outside of a manufactured home park or subdivision; (ii) in a new manufactured home park or subdivision; (iii) in an expansion to an existing manufactured home park or subdivision; or (iv) in 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 at least two (2) feet above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

    b)

    Require that manufactured homes to be placed or substantially improved on sites in existing manufactured home parks or subdivisions that are not subject to the provisions in Subparagraph a) above be elevated so that either (i) the lowest floor of the manufactured home is at least two (2) feet above the base flood elevation, or (ii) the manufactured home chassis is supported by reinforced piers or other foundation elements that are not less than thirty-six (36) inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

    f.

    Recreational vehicles. Require that recreational vehicles either shall: (1) be on the site for fewer than one hundred eighty (180) consecutive days; (2) be fully licensed and ready for highway use; or (3) meet the permit requirements and elevation and anchoring requirements for resisting wind forces.

    (3)

    Floodways. Located within areas of special flood hazard established in Paragraph (c)(2) above are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters 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 Subparagraph a. above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this Subsection.

    (4)

    Alteration of a watercourse. For all development purposes that alter a watercourse within a special flood hazard area, the following provisions apply:

    a.

    Channelization and flow diversion projects shall appropriately consider issues of sediment transport, erosion, deposition and channel migration, and properly mitigate potential problems through the project, as well as upstream and downstream of any improvement activity.

    b.

    Any channelization or other stream alteration activity proposed by a project proponent must be evaluated for its impact on the regulatory floodplain and be in compliance with all applicable federal, state and local floodplain rules, regulations and ordinances.

    c.

    Any stream alteration activity shall be designed and sealed by a registered Colorado professional engineer.

    d.

    Within a regulatory floodway, stream alteration activities shall not be constructed unless the project proponent demonstrates through a floodway analysis and report, sealed by a registered Colorado professional engineer, that there is not more than a 0.00-foot rise in the proposed conditions compared to existing conditions floodway resulting from the project, otherwise known as a no-rise certification, unless the community first applies for a CLOMR and a floodway revision.

(Ord. 3.171.3 §1, 2016; Ord. 1.467 §§31, 32, 2015; Ord. 3.01.102 §1, 2013)