Chapter 14.60
FLOOD DAMAGE PREVENTION REGULATIONS
Sections:
14.60.010 Statutory authorization.
14.60.030 Statement of purpose.
14.60.040 Methods of reducing flood losses.
14.60.060 Lands to which this chapter applies.
14.60.070 Basis for establishing the areas of special flood hazard.
14.60.090 Abrogation and greater restriction.
14.60.110 Warning and disclaimer of liability.
14.60.130 Designation of the building official.
14.60.140 Duties and responsibilities of the building official.
14.60.180 Standards for critical facilities.
14.60.010 Statutory authorization.
The Legislature of the state of Colorado has, in Section 31-23-101, C.R.S., delegated the responsibility to local government units to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. (Ord. 9-2000 § 1; Code 1997 § 14-6-1).
14.60.020 Findings of fact.
A. The flood hazard areas of the city of Gunnison are subject to periodic inundation which results 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. (Ord. 9-2000 § 1; Code 1997 § 14-6-2).
14.60.030 Statement of purpose.
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 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 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. (Ord. 9-2000 § 1; Code 1997 § 14-6-3).
14.60.040 Methods of reducing flood losses.
In order to accomplish its purposes, this chapter 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 flood waters;
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 flood waters or which may increase flood hazards in other areas. (Ord. 9-2000 § 1; Code 1997 § 14-6-4).
14.60.050 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 official’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 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.
“Base flood elevation (BFE)” 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.
“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” means a structure or related infrastructure, but not the land on which it is situated, as specified in GMC 14.60.180, Standards for critical facilities, 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. See GMC 14.60.180.
“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, drilling operations, or storage of equipment and/or materials located within the area of special flood hazard.
“Duct system” means all ducts, duct fittings, plenums, and fans assembled to form a continuous passageway for the distribution of air.
“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 in this chapter.
“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 to the pouring of concrete pads).
“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.
“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 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 the floodplain management ordinance codified in this chapter.
“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 foot.
“Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.
“Historic structure” means any structure that is:
1. Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;
2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;
3. Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or
4. Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:
a. By an approved state program as determined by the Secretary of the Interior; or
b. Directly by the Secretary of the Interior in states without approved programs.
“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 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 construction” means structures for which the “start of construction” commenced on or after the effective date of the original ordinance codified in this chapter, 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 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 these 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. The supporting technical data should be based on the standard step-backwater computer model used to develop the 100-year floodway shown on the Flood Insurance Rate Map (FIRM) or Flood Boundary and Floodway Map (FBFM).
“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 recreation, 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. 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 or 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 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
2. Any alteration of a “historic structure”; provided, that the alteration will not preclude 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.
“Water surface elevation” means the height, in relation to the North American Vertical Datum (NAVD) of 1988 (or other datum, where specified), of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas. (Ord. 8-2013 § 2; Ord. 1-2004 § 1; Ord. 9-2000 § 1; Code 1997 § 14-6-5).
14.60.060 Lands to which this chapter applies.
This chapter shall apply to all areas of special flood hazard and areas removed from the floodplain by a FEMA approved LOMR-F within the jurisdiction of the city of Gunnison. (Ord. 8-2013 § 3; Ord. 9-2000 § 1; Code 1997 § 14-6-6).
14.60.070 Basis for establishing the areas of special flood hazard.
The areas of special flood hazard identified by the Federal Management Agency in a scientific and engineering report entitled, “The Flood Insurance Study for the city of Gunnison, Gunnison County, Colorado,” dated November 16, 1982, with an accompanying Flood Insurance Rate Map (FIRM), is hereby adopted by reference and declared to be a part of this chapter. The flood insurance study and FIRM are on file at the city of Gunnison, Building Department, 201 W. Virginia Ave., Gunnison, CO 81230. (Ord. 9-2000 § 1; Code 1997 § 14-6-7).
14.60.080 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. (Ord. 9-2000 § 1; Code 1997 § 14-6-8).
14.60.090 Abrogation and greater restriction.
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. (Ord. 9-2000 § 1; Code 1997 § 14-6-9).
14.60.100 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. (Ord. 9-2000 § 1; Code 1997 § 14-6-10).
14.60.110 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 city of Gunnison, 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. (Ord. 9-2000 § 1; Code 1997 § 14-6-11).
14.60.120 Development permit.
A development permit shall be obtained before construction or development begins within any area of special flood hazard established in GMC 14.60.070. Application for a development permit shall be made on forms furnished by the building official and may include, but not be limited to:
A. 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.
B. Where base flood elevations are utilized, all new construction, substantial improvements and other development must comply with the requirements of GMC 14.60.140(B), Use of Other Base Flood Data. (Ord. 9-2000 § 1; Code 1997 § 14-6-12).
14.60.130 Designation of the building official.
The building official is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. (Ord. 9-2000 § 1; Code 1997 § 14-6-13).
14.60.140 Duties and responsibilities of the building official.
Duties of the building official shall include, but not be limited to:
A. Permit Review.
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 GMC 14.60.180(A) are met.
B. Use of Other Base Flood Data. When base flood data has not been provided in accordance with GMC 14.60.070, Basis for establishing the areas of special flood hazard, the building official shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from any federal, state, or other source. Where base flood elevation data are utilized, all new construction, substantial improvements, or other development in Zone A are administered in accordance with subsection (C) of this section, Information to Be Obtained and Maintained, and GMC 14.60.170, Specific standards.
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 GMC 14.60.170(B)(3).
3. Maintain for public inspection all records pertaining to the provisions of this chapter.
4. Inspect all development at appropriate times during the period of construction to ensure compliance with all provisions of this chapter, including proper elevation of the structure.
5. For waterways with base flood elevations for which a regulatory floodway has not been designated, no new construction, substantial improvements, or other development (including fill) shall be permitted within zones A1-30 and AE on the community’s FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one-half foot at any point within the community.
6. Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in zones A1-30, AE, AH, on the community’s FIRM which increases the water surface elevation of the base flood by more than one-half foot; provided, that the community first applies for a conditional FIRM revision through FEMA (conditional letter of map revision), fulfills the requirements for such revisions as established under the provisions of Section 65.12 and receives FEMA approval.
D. Alteration of Watercourses.
1. Notify adjacent communities, the District 10 regional planning commission 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.
3. 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. A detailed analysis of sediment transport and overall channel stability should be considered, when appropriate, to assist in determining the most appropriate design.
4. Channelization and flow diversion projects shall evaluate the residual 100-year floodplain.
5. 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.
6. Any stream alteration activity shall be designed and sealed by a registered Colorado professional engineer or certified professional hydrologist.
7. All activities within the regulatory floodplain shall meet all applicable federal, state and city of Gunnison floodplain requirements and regulations.
8. Within the 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 the existing conditions floodway resulting from the project, otherwise known as a no-rise certification, unless the community first applies for a CLOMR and floodway revision.
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 GMC 14.60.150. (Ord. 8-2013 §§ 4, 5; Ord. 9-2000 § 1; Code 1997 § 14-6-14).
14.60.150 Variance procedure.
A. Appeal Board.
1. The zoning board of adjustments and appeals (ZBOA), as established by the city of Gunnison, shall hear and decide appeals and requests for variances from the requirements of this chapter.
2. The ZBOA shall hear and decide appeals when it is alleged there is an error in any requirement, decisions, or determination made by the building official in the enforcement or administration of this chapter.
3. Those aggrieved by the decision of the ZBOA, or any taxpayer, may appeal such decisions to the district court, as provided by law.
4. In passing upon such applications, the ZBOA 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 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 factors of subsection (A)(4) of this section and the purposes of this chapter, the ZBOA may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.
6. The building official 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 flood level, providing subsections (A)(4)(a) through (A)(4)(k) of this section have been fully considered. As the lot size increases beyond one-half acre, the technical justifications required for issuing the variance increases.
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 a 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 applicants; 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, 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 the 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. (Ord. 8-2013 § 6; Ord. 9-2000 § 1; Code 1997 § 14-6-15).
14.60.160 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 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 developments which contain at least 50 lots or five acres (whichever is less). (Ord. 9-2000 § 1; Code 1997 § 14-6-16).
14.60.170 Specific standards.
In all areas of special flood hazard including properties removed from the floodplain by fill (LOMR-F), where base flood elevation data has been provided as set forth in GMC 14.60.070, Basis for establishing the areas of special flood hazard, or GMC 14.60.140(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) electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities (including ductwork) elevated to one foot 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) electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities (including ductwork) elevated to one foot 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 one foot above the base flood level with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
C. 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 openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided;
2. The bottom of all openings shall be no higher than one foot above grade; and
3. Openings may be equipped with screens, louvers, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters.
D. Manufactured Homes.
1. Manufactured homes shall be anchored in accordance with GMC 14.60.160(A)(2).
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 a result of a flood;
be elevated on a permanent foundation such that the lowest floor of the manufactured home and all of the duct system is elevated to one foot or more 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 subsection (D)(2)(a) of this section be elevated so that either:
i. The lowest floor of the manufactured home is at least one foot above the base flood elevation; or
ii. The manufactured home chassis is supported by reinforced piers or other foundation elements that are no less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
E. Recreational Vehicles.
1. Require that recreational vehicles either:
a. Be on the site for fewer than 180 consecutive days;
b. Be fully licensed and ready for highway use; or
c. Meet the permit requirements and elevation and anchoring requirements for manufactured homes. (Ord. 8-2013 §§ 7, 8; Ord. 1-2004 §§ 2, 3, 4; Ord. 9-2000 § 1; Code 1997 § 14-6-17).
14.60.180 Standards for critical facilities.
A critical facility is a structure or related infrastructure, but not the land on which it is situated, as specified in Rule 6 of the Rules and Regulations for Regulatory Floodplains in Colorado, 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.
A. Classification of Critical Facilities. It is the responsibility of the city of Gunnison to identify and confirm that specific structures in their community meet the following criteria:
1. Critical facilities are classified under the following categories: essential services, hazardous materials, at-risk populations, and vital to restoring normal services.
a. Essential Services Facilities. Include public safety, emergency response, emergency medical, designated emergency shelters, communications, public utility plant facilities, and transportation lifelines. These facilities consist of:
i. Public safety (police stations, fire and rescue stations, emergency vehicle and equipment storage, and emergency operation centers);
ii. Emergency medical (hospitals, ambulance service centers, urgent care centers having emergency treatment functions, and nonambulatory surgical structures but excluding clinics, doctor offices, and non-urgent-care medical structures that do not provide these functions);
iii. Designated emergency shelters;
iv. Communications (main hubs for telephone, broadcasting equipment for cable systems, satellite dish systems, cellular systems, television, radio, and other emergency warning systems, but excluding towers, poles, lines, cables, and conduits);
v. Public utility plant facilities for generation and distribution (hubs, treatment plants, substations and pumping stations for water, power and gas, but not including towers, poles, power lines, buried pipelines, transmission lines, distribution lines, and service lines); and
vi. Air transportation lifelines (airports (municipal and larger), helicopter pads and structures) serving emergency functions, and associated infrastructure (aviation control towers, air traffic control centers, and emergency equipment aircraft hangars);
vii. Specific exemptions to this category include wastewater treatment plants (WWTP), nonpotable water treatment and distribution systems, and hydroelectric power generating plants and related appurtenances;
viii. Public utility plant facilities may be exempted if it can be demonstrated to the satisfaction of the {community governing body} that the facility is an element of a redundant system for which service will not be interrupted during a flood. At a minimum, it shall be demonstrated that redundant facilities are available (either owned by the same utility or available through an intergovernmental agreement or other contract) and connected, the alternative facilities are either located outside of the 100-year floodplain or are compliant with the provisions of this chapter, and an operations plan is in effect that states how redundant systems will provide service to the affected area in the event of a flood. Evidence of ongoing redundancy shall be provided to the {community governing body} on an as-needed basis upon request.
b. Hazardous Materials Facilities. Include facilities that produce or store highly volatile, flammable, explosive, toxic and/or water-reactive materials. These facilities may include:
i. Chemical and pharmaceutical plants (chemical plant, pharmaceutical manufacturing);
ii. Laboratories containing highly volatile, flammable, explosive, toxic and/or water-reactive materials;
iii. Refineries;
iv. Hazardous waste storage and disposal sites; and
v. Above ground gasoline or propane storage or sales centers;
vi. Facilities shall be determined to be critical facilities if they produce or store materials in excess of threshold limits. If the owner of a facility is required by the Occupational Safety and Health Administration (OSHA) to keep a Material Safety Data Sheet (MSDS) on file for any chemicals stored or used in the workplace, and the chemical(s) is stored in quantities equal to or greater than the threshold planning quantity (TPQ) for that chemical, then that facility shall be considered to be a critical facility. The TPQ for these chemicals is: either 500 pounds or the TPQ listed (whichever is lower) for the 356 chemicals listed under 40 CFR Section 302 (2010), also known as extremely hazardous substances (EHS); or 10,000 pounds for any other chemical. This threshold is consistent with the requirements for reportable chemicals established by the Colorado Department of Health and Environment. OSHA requirements for MSDS can be found in 29 CFR Section 1910 (2010). The Environmental Protection Agency (EPA) regulation “Designation, Reportable Quantities, and Notification,” 40 CFR Section 302 (2010) and OSHA regulation “Occupational Safety and Health Standards,” 29 CFR Section 1910 (2010) are incorporated herein by reference and include the regulations in existence at the time of the promulgation of the ordinance codified in this chapter, but exclude later amendments to or editions of the regulations.
c. Specific exemptions to this category include:
i. Finished consumer products within retail centers and households containing hazardous materials intended for household use, and agricultural products intended for agricultural use.
ii. Buildings and other structures containing hazardous materials for which it can be demonstrated to the satisfaction of the local authority having jurisdiction by hazard assessment and certification by a qualified professional (as determined by the local jurisdiction having land use authority) that a release of the subject hazardous material does not pose a major threat to the public.
iii. Pharmaceutical sales, use, storage, and distribution centers that do not manufacture pharmaceutical products.
iv. These exemptions shall not apply to buildings or other structures that also function as critical facilities under another category outlined in this section.
d. At-Risk Population Facilities. Include medical care, congregate care, and schools. These facilities consist of:
i. Elder care (nursing homes);
ii. Congregate care serving 12 or more individuals (day care and assisted living);
iii. Public and private schools (pre-schools, K-12 schools), before-school and after-school care serving 12 or more children.
e. Facilities Vital to Restoring Normal Services. Including government operations, these facilities consist of:
i. Essential government operations (public records, courts, jails, building permitting and inspection services, community administration and management, maintenance and equipment centers);
ii. Essential structures for public colleges and universities (dormitories, offices, and classrooms only).
f. These facilities may be exempted if it is demonstrated to the city of Gunnison that the facility is an element of a redundant system for which service will not be interrupted during a flood. At a minimum, it shall be demonstrated that redundant facilities are available (either owned by the same entity or available through an intergovernmental agreement or other contract), the alternative facilities are either located outside of the 100-year floodplain or are compliant with this chapter, and an operations plan is in effect that states how redundant facilities will provide service to the affected area in the event of a flood. Evidence of ongoing redundancy shall be provided to the city of Gunnison on an as-needed basis upon request.
2. Protection for Critical Facilities. All new and substantially improved critical facilities and new additions to critical facilities located within the special flood hazard area shall be regulated to a higher standard than structures not determined to be critical facilities. For the purposes of this chapter, protection shall include one of the following:
a. Location outside the special flood hazard area; or
b. Elevation of the lowest floor or floodproofing of the structure, together with attendant utility and sanitary facilities, to at least two feet above the base flood elevation.
3. Ingress and Egress for New Critical Facilities. New critical facilities shall, when practicable as determined by the city of Gunnison, have continuous noninundated access (ingress and egress for evacuation and emergency services) during a 100-year flood event. (Ord. 8-2013 § 9).
14.60.190 Floodways.
Located within areas of special flood hazard established in GMC 14.60.070 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 GMC 14.60.160, General standards, and GMC 14.60.170, Specific standards. (Ord. 8-2013 § 1; Ord. 9-2000 § 1; Code 1997 § 14-6-18. Formerly 14.60.180).
14.60.200 Penalty.
Any person, firm, or corporation violating any provision of this chapter shall be fined or imprisoned in accordance with GMC 4.20.010, and a separate offense shall be deemed committed on each day a violation occurs or continues. (Ord. 8-2013 § 1; Ord. 9-2000 § 1; Code 1997 § 14-6-19. Formerly 14.60.190).