A. Purpose: The purposes of these storm water management provisions are to protect life and property from reasonably preventable flood hazards; protect the quality of surface waters from contamination, and to minimize loss of valuable wildlife by preserving habitat and linkages between wildlife habitat areas.
B. Design Objectives:
1. Minimum Interference: In rural, suburban and, where appropriate, urban areas, natural drainageways shall be retained to minimize interference with floodwater conveyance, floodwater storage, wetlands, and both surface and subsurface hydrology. The director of public works may approve modifications to natural channels that are consistent with the other provisions of the UDO.
2. Exposure; Nuisances: Development design should comply with CCRFCD's hydrologic criteria and drainage design manual and reduce the exposure of people and property to flood hazards and nuisances associated with inadequate management of storm water runoff.
3. Erosion: Erosion and sedimentation problems should be minimized to conserve/enhance water quality and conserve valuable topsoil.
4. Floods: Development design should accommodate large floods and smaller, more frequent floods along major and minor waterways.
5. Future Expenses: Storm water systems should be designed to minimize future operational and maintenance expenses.
6. Public Facilities Exposure: Storm water systems should be designed to reduce the exposure of streets, utilities and other public facilities to damage from storm water.
7. Rescue And Relief Efforts: Development design should minimize need for rescue and relief efforts from floods and provide sufficient access for such efforts when needed.
C. Floodplain Management:
1. Scope Of Floodplain Management: The provisions of this section shall apply to all areas of the city identified on the flood insurance rate maps (FIRM) or floodway maps as promulgated by the federal emergency management agency (FEMA).
2. Disclaimer Of Liability: The provisions of this section do not imply or otherwise warrant that areas outside of the FIRM or floodway maps will be free from flooding or flood damage, nor does this subsection create liability on the part of the city, its officers or employees for any flood damages that may result from reliance on these floodplain management provisions, FEMA or any regulations or administrative decision made hereunder.
3. Permit Required: In all areas covered by these floodplain management provisions, no development or construction, including manufactured homes, located, extended, converted, structurally altered or otherwise shall be permitted except upon city issuance of a permit to develop granted under the procedures stated herein.
a. No person shall initiate any development, construction or substantial improvement or cause the same to be done within a designated floodplain without first obtaining a separate permit for development under these floodplain management provisions and in compliance with FEMA regulations.
b. Application for a permit for development, construction or substantial improvement within a designated floodplain shall be made in accordance with CCRFCD regulations.
4. Residences Within Designated Floodplain: All residences to be placed or substantially improved within a designated floodplain shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at least eighteen inches (18") above base flood elevation and shall be permanently anchored to said foundation.
5. Preventing Water Accumulation: 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.
6. Automatic Equalization Of Hydrostatic Flood Forces: 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 floodwater. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria: A minimum of two (2) openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be no higher than one foot (1') above grade. Openings may be equipped with screens, louvers or other coverings or devices; provided, that they permit the automatic entry and exit of floodwater.
7. Enforcement Officer: The director of public works or building official is hereby designated as the enforcement officer for compliance under these floodplain management provisions and FEMA regulations.
8. Duties Of Enforcement Officer: The duties of the enforcement officer shall include, but not be limited to, the following:
a. Review of all applications for development permits to require that sites are reasonably safe from flooding and that the permit requirements of this section have been satisfied as well as the other requirements of these regulations;
b. Review of all permits for proposed developments to confirm that all necessary permits have been obtained from those federal, state or local governmental agencies from which prior approval is required;
c. Notify adjacent communities and the appropriate state agencies prior to any alteration or relocation of a watercourse, and to provide evidence of such notification for FEMA;
d. Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood carrying capacity is not diminished;
e. Require verification, recording and updating of records of the actual elevation (in relation to mean sea level) of the lowest floor (including basement) of all new or substantially improved structures, using reference marks (RM) established by FEMA;
f. Require verification, recording and updating of records of the actual elevation (in relation to mean sea level) using reference marks (RM) established by FEMA, to which the new or substantially improved structures have been floodproofed and certified by a qualified individual as defined by FEMA when "floodproofing", as defined herein, is utilized for a particular structure;
g. Take any actions necessary to assure compliance with FEMA regulations in the granting or denial of applications for any permits in a designated floodplain;
h. Require that all proposals for subdivisions and other new development (including manufactured home subdivisions or parks) are consistent with the need to minimize flood damage and that:
(1) All public utilities and facilities such as sewer, gas, electrical and water systems are located, elevated and constructed to minimize or eliminate damage from floods; and
(2) Adequate drainage is provided for the purpose of reducing exposure to flood hazards; and
(3) Regulatory flood elevations utilizing FEMA "RM" are included in all proposals for all development.
9. Floodplain Permit Application Requirements: All written applications for development or substantial improvement in a designated floodplain shall:
a. Identify and describe the development to be covered by the permit;
b. Describe the land on which the proposed development is to be done by lot, block, tract and house and street address, or similar description that will readily identify and definitely locate the proposed building or development;
c. Indicate the use or occupancy for which the proposed development is intended;
d. Be accompanied by plans and specifications for proposed construction;
e. Be signed by the proposed permittee or his authorized agent who may be required to submit evidence to indicate such authority;
f. Provide such other information as reasonably may be required by the enforcement officer or as required from the applicant under any part of these regulations, including, but not limited, to evidence of compliance with FEMA regulations or guidelines for anchoring to prevent flotation and lateral movement, the use of flood resistant materials and utility equipment and construction methods which minimize flood damage.
10. Floodplain Considerations In Granting Variances: The board of zoning adjustment and Clark County flood control district shall hear and decide appeals and requests for variances from the requirements of this subsection. In all situations, the board shall begin its consideration based on the premise that variances are disfavored and should only be allowed upon a strong showing by the applicant that the circumstances dictate otherwise. In passing upon such applications, the board shall consider all technical evaluations, all relevant factors, standards specified in other sections of these regulations; 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 land use to flood damage and the effect of such damage on the individual owner;
d. The importance of the services provided by the proposed land use to the community;
e. The necessity to the proposed land use of a waterfront location, where applicable;
f. The availability of alternative locations, not subject to flooding or erosion damage, for the proposed land use;
g. The compatibility of the proposed land use with existing and anticipated development;
h. The relationship of the proposed land 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, and streets and bridges. (Ord. 172, 9-24-1996, eff. 10-31-1996)