Floodplain Management - 15.40

The Legislature of the State of Colorado has in 31-23-100 et seq., CRS, 1973, as amended, delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety and general welfare of its citizenry.

1. The flood hazard areas of the Town are subject to periodic inundation which may 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.
2. These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards 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.

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

1. Protect human life and health;
2. Minimize expenditure of public money for costly flood control projects;
3. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
4. Minimize prolonged business interruptions;
5. Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, street and bridges located in the area of special flood hazard;
6. Help maintain a stable tax base by providing for the second use and development of areas of special flood hazard so as to minimize future flood blight area;
7. Insure that potential buyers are notified that property is in an area of special flood hazard; and
8. Insure that those who occupy the areas of special flood hazard assume responsibility for their actions.

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

1. “Appeal” means a request for a review of the Town manager’s interpretation of any provision of this chapter or a request for a variance.
2. “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.
3. “Base flood” means the flood having a one percent (1%) chance of being equaled or exceeded in any given year.
4. “Critical feature” means an integral and readily identifiable part of a flood protection system, without which the flood protection provided by the entire system would be compromised.
5. “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 special flood hazard.
6. “Existing manufactured home park” or “manufactured home subdivision” means a manufactured home park or manufactured home subdivision for which the construction of facilities for servicing the lot on which the manufactured homes are to be affixed, including, as 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 provisions of this in this chapter.
7. “Expansion to an existing manufactured home park” or ”manufactured home 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.
8. “Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from the overflow of inland or tidal waters, and/or the unusual and rapid accumulation or runoff of surface waters from any source.
9. “Flood insurance rate map (FIRM)” means the official map on which the Federal Emergency Management Agency has delineated both the area of special flood hazards and the risk premium zones applicable to the community.
10. “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.
11. “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.
12. “Levee” means a man-made structure, usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding.
13. “Levee system” means a flood protection system which consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accordance with sound engineering practices.
14. “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 non-elevation design requirements of this Chapter.
15. “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 connected to the required utilities. The term “manufactured home” does not include a “recreational vehicle.”
16. “Mean sea level” means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a community’s flood insurance rate map are referenced.
17. “New construction” means structures for which the start of construction commenced on or after December 1, 1977.
18. “New manufactured home park” or” manufactured home subdivision” means a parcel, or contiguous parcels, of land divided into two or more manufactured home lots for rent or sale for which the construction of facilities for servicing the lot, including, at a minimum, the installation of utilities, either final site grading or the pouring of concrete pads, and the construction of streets, is completed on or after the effective date of the provisions of this Chapter.
19. “Program deficiency” means a defect in a community’s flood plain management regulations or administrative procedures that impairs effective implementation of those flood plain management regulations or of the NFIP standards in 60.3, 60.4, 60.5, or 60.6.
20. “Recreational Vehicle” means a vehicle which is built on a single chassis; four hundred (400) square feet or less when measured at the largest horizontal projections; designed to be self-propelled or permanently towable by a light duty truck; and designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
21. “Remedy a violation” means to bring the structure or other development into compliance with state or local flood plain management regulations or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of the ordinance or otherwise deterring future similar violations, or reducing federal financial exposure with regard to the structure or other development.
22. “Start of construction” includes substantial improvement and means the date of the building permit was issued, provided 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 of a structure on the site, such as the pouring of a 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.
23. “Structure” means a walled and roofed building or manufactured home that is principally above ground.
24. “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 fifty percent (50%) of the market value of the structure before the damage occurred.
25. “Substantial improvement” means any 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. This term includes structures which have incurred “substantial damage”, regardless of the actual repair work performed. The term does not, however, include either any project for improvement of a structure to comply with existing state or local health, sanitary or safety code specifications which are solely necessary to assure safe living conditions; or any alteration of a structure listed on the National Register of Historic Places or the State Inventory of Historic Places.
26. “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.

In order to accomplish its purposes, this chapter includes methods and provisions for:

1. 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;
2. Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;'
3. Controlling the alteration of natural floodplains, stream channels and natural protective barriers, which help accommodate or channel flood waters;
4. Controlling filling, grading, dredging and other development which may increase flood damage; and '
5. Preventing or regulating the construction of flood barriers which may unnaturally divert floodwaters or which may increase flood hazards in other areas.

1. Land to Which This Chapter Applies. This chapter shall apply to all areas of special flood hazard 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 the Town of Rangely, effective September 28, 1990, with an accompanying flood insurance rate map is adopted by reference and declared to be a part of this chapter. The Flood Insurance Study is on file at the Municipal Building, Rangely, Colorado.
3. 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.
4. 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 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 chapter, all provisions shall be considered as minimum requirements, liberally construed in favor of the governing body, and 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 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, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.

1. Establishment of Development Permit. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in Section 15.40.060 General provisions of this Chapter. Application for a development permit shall be made on forms furnished by the Town manager 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 structure; 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 applicable floodproofing criteria in Section 15.40.080 Provisions for flood hazard reduction of this Chapter; and
   4. Description of the extent to which any water course will be altered or relocated as a result of proposed development. All elevation shall be determined by using the benchmark identified by the Federal Emergency Management Agency in its flood insurance rate map.
2. Designation of the Town Manager. The Town manager is appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions.
3. Duties and Responsibilities of the Town Manager. Duties of the Town manager shall include, but not be limited to:
   1. Permit Review. Review all development permits to determine that the permit requirements of this chapter have been satisfied; and review all development permits to determine that all necessary permits have been obtained from those federal, State or local governmental agencies from which prior approval is required; 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 subsection C of Section 15.40.080 Provisions for flood hazard reduction of this Chapter are met.
   2. Use of Other Base Flood Data. When the base flood elevation has not been provided in accordance with Section 15.40.060 General Provisions herein, the Town manager shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from federal, state or other sources, in order to administer Section 15.40.080 Provisions for flood hazard reduction of this Chapter .
   3. 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.
      2. For all new or substantially improved floodproofed structures: verify and record the actual elevation, in relation to mean sea level; and maintain the floodproofing certifications required in subsection A of this section.
      3. Maintain for public inspection all records pertaining to the provisions of this Chapter.
   4. Alteration of Watercourses.
      1. Notify adjacent communities and 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.
   5. Interpretation of FIRM Boundaries. Make interpreta­tions, where needed, as to the exact location of the boundaries of the areas of special flood hazards: for example, where there appears to be a conflict between a mapped boundary and actual field conditions. The persons contesting the location of the boundary shall be given reasonable opportunity to appeal the interpretation as provided in subsection D of this Section.
4. Variance Procedure.
   1. Appeal Board. The board of zoning adjustment, as established by the Town, shall hear and decide appeals and requests for variances from the requirements of this chapter. The board of zoning adjustment shall hear and decide appeals when it is alleged there is an error in any requirement, decision or determination made by the Town manager in the enforcement or administration of this chapter. Those aggrieved by a decision of the board of zoning adjustment, or any taxpayer, may appeal such decision to the district court for the County, as provided by law. In passing upon such applications, the board of zoning adjustment shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and:
      1. The danger that materials may be swept onto other lands to the injury of others;
      2. The danger to life and property due to flooding or erosion damage;
      3. The susceptibility of the proposed facility and its contents to flood damage, and the effect of such damage on the individual owner;
      4. The important of the services provided by the proposed facility to the community;
      5. The necessity to the facility of a waterfront location, where applicable;
      6. The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;
      7. The compatibility of the proposed use with existing and anticipated development;
      8. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;
      9. The safety of the access to the property in times of flood for ordinary and emergency vehicles;
      10. The expected heights, velocity, duration, rate or rise, and sediment transport of the floodwaters, and the effects of wave action, if applicable, expected at the site; and
      11. 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, and streets and bridges.
   2. Variances generally. Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (1/2) acre or less in size, contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing all items in paragraph (d) above have been fully considered. As the lot size increased beyond one-half (1/2) acre, the technical justification required for issuing the variance increases.
   3. Factors considered. Upon consideration of the factors in paragraph D (1) above and the purposes of this Chapter, the board of zoning adjustment may attach such conditions to the granting of variances as it deems necessary to further the purposes of this Chapter.
   4. Records and reports. The Town manager shall maintain the records of all appeal actions and report any variances to the Federal Emergency Management Agency upon request.
5. Conditions for Variances. 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. Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief. Variance shall only be issued upon:
   1. A showing of good and sufficient cause;
   2. A determination that failure to grant the variance would result in exceptional hardship to the applicant; and
   3. 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, or conflict with existing local laws or provisions of this Code.
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 elevation below the base flood elevation, and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation.

1. General Standards. In all areas of special flood hazard the following standards are required:
   1. Anchoring.
      1. All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure and to withstand hydrodynamic loads.
      2. All manufactured homes shall be anchored to resist flotation, collapse or lateral movement by providing over-the-top and frame ties to ground anchors. Specific requirements shall be that 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; 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; all components of the anchoring system be capable of carrying a force of our thousand eight hundred (1,800) pounds; and any additions to the manufactured home be similarly anchored.
   2. 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. 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: A minimum of two openings having a total net area of not less than one (1) square inch for every square foot of enclosed are subject to flooding shall be provided. The bottom of all openings shall be no higher than one (1) foot above grade. Openings may be equipped with screen, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters. This provision applies only to homes constructed with the lowest floor at or above the base flood elevation.
   3. 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 system into floodwater; and
      3. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
      4. Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
   4. 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 developments which contain at least fifty (50( lots of 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 Section 15.40.060 General provisions or Section 15.40.070 Administration of this Chapter, the following provisions are required:
   1. Residential Construction. New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the base floor elevation.
   2. 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 level 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. Provide that where a non-residential structure is intended to be made watertight below the base flood level, (I) A registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for the construction, an shall certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the applicable provisions of this section, and (II) A record of such certificates which includes the specific elevation (in relation to mean sea level) tow which such structures are floodproofed shall be maintained with the official designated by the community under subsection B of Section 15.40.070 Administration of this Chapter.
   3. Manufactured Homes. All manufactured homes or those to be substantially improved shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the base flood elevation and is securely anchored to an adequately anchored foundation system. This paragraph applies to manufactured homes to be placed o substantially improved in an expansion to an existing manufactured home park or subdivision. This paragraph does not apply to manufactured homes to be placed or substantially improved in an existing manufactured home park or subdivision.
3. Floodways. Located within areas of special flood hazard established in Section 15.40.060 General provisions of this Chapter 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:
   1. Encroachments are prohibited, including fill, new construction, substantial improvements, and other development, unless certification by a registered professional engineer or architect is provided demonstrating that encroachments will not result in any increase in flood levels during the occurrence of the base flood discharge.
   2. If paragraph 1. above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section.