Source: https://www.codepublishing.com/CA/ElkGrove/html/ElkGrove16/ElkGrove1650.html
Timestamp: 2019-12-07 11:14:10
Document Index: 764586589

Matched Legal Cases: ['§5', '§3', '§5', '§3', '§5', '§2', '§3', '§5', '§3', '§5', '§3', '§5']

Chapter 16.50 FLOOD DAMAGE PREVENTION
16.50.030 Administration.
16.50.040 General provisions.
16.50.050 Floodplain development permit.
16.50.060 Provisions for flood hazard reduction.
It is the purpose of this chapter to enact regulations applied uniformly throughout the community to all publicly and privately owned land within flood-prone areas. These regulations are designed to:
E. Minimize damage to public facilities and utilities such as water and gas mains; electric, telephone, and sewer lines; and streets and bridges located in areas of special flood hazard;
The City’s intent in adopting this chapter is to provide floodplain management regulations, as authorized under Sections 65302, 65560 and 65800 of the California Government Code, and similar sections. [Ord. 15-2016 §5 (Exh. C), eff. 9-23-2016]
For the purposes of this chapter, the following terms, phrases, and words shall have the following definitions:
1. A Zone. See definition for “Special flood hazard area (SFHA).”
2. “Accessory building” means an accessory building as defined in EGMC Title 23.
3. “Accessory building, small” means an accessory building, as defined in EGMC Title 23, with an enclosed space of less than one hundred twenty (120 ft2) square feet.
4. “Accessory structure” means an accessory structure as defined in EGMC Title 23.
5. “Accessory use” means a use which is incidental and subordinate to the principal use of the parcel of land on which it is located.
6. “Alluvial fan” means a geomorphologic feature characterized by a cone- or fan-shaped deposit of boulders, gravel, and fine sediments that have been eroded from mountain slopes, transported by flood flows, and then deposited on the valley floors, and which is subject to flash flooding, high-velocity flows, debris flows, erosion, sediment movement and deposition, and channel migration.
7. “Apex” means a point on an alluvial fan or similar landform below which the flow path of the major stream that formed the fan becomes unpredictable and alluvial fan flooding can occur.
8. “Appeal” means a request for a review of the Floodplain Administrator’s interpretation of any provision of this chapter.
9. “Area of shallow flooding” means a designated AO or AH Zone on the Flood Insurance Rate Map (FIRM). The base flood depths range from one (1') foot to three (3') feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
10. “Area of special flood hazard” means an area designated as a special flood hazard area (SFHA).
1. “Base flood” means a flood which has a one (1%) percent chance of being equaled or exceeded in any given year (also called the one hundred (100) year flood). “Base flood” is the term used throughout this chapter.
2. “Base flood elevation (BFE)” means the water surface elevation resulting from a flood that has a one (1%) percent or greater chance of being equaled or exceeded in any given year (one hundred (100) year flood). The BFE is shown on Flood Insurance Rate Maps as Zones AE and AH. For unmapped areas, the BFE shall be analyzed and established as directed and approved by the Floodplain Administrator.
3. “Basement” means any area of the building having its floor subgrade (i.e., below ground level) on all sides.
4. “Building” means a building as defined in EGMC Title 23.
1. “City Council” means the City Council of the City of Elk Grove.
1. “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, or storage of construction equipment or materials.
1. “Encroachment” means the advance or infringement of uses, plant growth, fill, excavation, buildings, permanent structures, or development into a floodplain which may impede or alter the flow capacity of a floodplain.
2. “Existing 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) was completed before the effective date of the ordinance codifying this chapter.
3. “Expansion to an existing manufactured home park or subdivision” means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).
1. “Flood, flooding, or floodwater” means:
a. A general and temporary condition of partial or complete inundation of normally dry land areas from the overflow of inland waters and the unusual and rapid accumulation or runoff of surface waters from any source; and
2. “Flood Insurance Rate Map (FIRM)” means the official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.
3. “Flood Insurance Study” means the official report provided by the Federal Insurance Administration that may include flood profiles, the Flood Insurance Rate Map, the Flood Boundary and Floodway Map, and the base flood elevation.
4. “Floodplain or flood-prone area” means any land area susceptible to being inundated by water from any source. See “Flood, flooding, or floodwater.”
5. “Floodplain Administrator” means the Public Works Director, or their designee, who is tasked with enforcing the floodplain management regulations.
6. “Floodplain management” means the operation of an overall program of corrective and preventive measures for reducing flood damage and preserving and enhancing, where possible, natural resources in the floodplain, including but not limited to emergency preparedness plans, flood control works, floodplain management regulations, and open space plans.
7. “Floodplain management regulations” means this chapter and other regulations in this municipal code, subdivision regulations, building codes, health regulations, special purpose regulations (such as grading and erosion control), and other application of police power which control development in flood-prone areas. This term describes Federal, State, or local regulations in any combination thereof which provide standards for preventing and reducing flood loss and damage.
8. “Flood-proofing” means any combination of structural and 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. For guidelines on dry and wet flood-proofing, see FEMA Technical Bulletins TB 1-93, TB 3-93, and TB 7-93.
9. “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. Also referred to as regulatory floodway.
10. “Floodway fringe” means that area of the floodplain on either side of the regulatory floodway where encroachment may be permitted.
G. “G” Definitions. Reserved for future use.
1. “Habitable structure” means any structure that is designed to be lived in or otherwise occupied for extended periods of time. Examples include, but are not limited to, residential units (single-family residences, apartments), commercial space, office space, or other similar areas with conditioned space.
2. “Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.
I. “I” Definitions. Reserved for future use.
J. “J” Definitions. Reserved for future use.
K. “K” Definitions. Reserved for future use.
1. “Local hazard mitigation plan” means a plan that incorporates a process whereby the potential of future loss due to flooding can be minimized by planning and implementing one (1) or more alternatives to floodplain management on a community-wide basis.
2. “Levee” means a manmade 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.
3. “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 accord with sound engineering practices.
4. “Lowest floor” means the lowest floor of the lowest enclosed area, including basement (see “Basement”). An unfinished or flood-resistant enclosure below the lowest floor that is 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 it conforms to applicable nonelevation design requirements, including, but not limited to:
a. The anchoring standards in EGMC Section 16.50.060(A)(1) (Anchoring);
b. The construction materials and methods standards in EGMC Section 16.50.060(A)(2) (Construction Materials and Methods);
c. The flood openings standards in EGMC Section 16.50.060(A)(3)(c) (Flood Openings); and
d. The standards for utilities in EGMC Section 16.50.060(B) (Standards for Utilities).
For residential structures, all subgrade enclosed areas are prohibited as they are considered to be basements (see “Basement”). This prohibition includes below-grade garages and storage areas that are attached to the main structure.
1. “Manufactured home” means a structure, transportable in one (1) 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.”
2. “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for rent or sale.
3. “Market value” means the value as determined by estimating the cost to replace the structure in new condition and adjusting that cost figure by the amount of depreciation which has accrued since the structure was constructed. The cost of replacement of the structure shall be based on a square foot cost factor determined by reference to a building cost estimating guide recognized by the building construction industry. The amount of depreciation shall be determined by taking into account the age and physical deterioration of the structure and its functional obsolescence, as approved by the Floodplain Administrator, but shall not include economic or other forms of external obsolescence. Use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be considered only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences.
4. “Mean sea level,” for purposes of the National Flood Insurance Program, means the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum (NAVD) of 1988, or other datum to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced.
1. “New construction,” for floodplain management purposes, means structures for which the “start of construction” commenced on or after the effective date of the ordinance codifying this chapter, and includes any subsequent improvements to such structures.
2. “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) was completed on or after the effective date of the ordinance codifying this chapter.
3. “Nonhabitable accessory structure” means a structure that is not designed to be lived in or otherwise occupied for long durations. Examples include, but are not limited to, garages not attached to the main structure, storage sheds, barns, carports, gazebos, patio covers, arbors, and play equipment.
1. “Obstruction” means, but is not limited to, any dam, wall, wharf, embankment, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, building, wire, fence, rock, gravel, refuse, fill, structure, vegetation, or other material in, along, across, or projecting into any watercourse which may alter, impede, retard, or change the direction and/or velocity of the flow of water, or due to its location, its propensity to snare or collect debris carried by the flow of water, or its likelihood of being carried downstream.
2. “One hundred (100) year flood” means as provided in the term “Base flood.”
1. “Program deficiency” means a defect in a community’s floodplain management regulations or administrative procedures that impairs effective implementation of those floodplain management regulations.
Q. “Q” Definitions. Reserved for future use.
1. “Recreational vehicle” means a vehicle which is:
b. Four hundred (400 ft2) square feet or less when measured at the largest horizontal projection;
2. “Regulatory floodway” means the channel of a river or other watercourse and the adjacent land areas, as determined by FEMA, that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation.
3. “Remedy a violation” means to bring the structure or other development into compliance with State or local floodplain management regulations, or if this is not physically possible due to site conditions, to reduce the impacts of its noncompliance to a level deemed acceptable to the City. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of the chapter or otherwise deterring future similar violations, or reducing State or Federal financial exposure with regard to the structure or other development.
4. “Riverine” means as relating to, formed by, or resembling a river (including tributaries), stream, brook, etc.
1. “Sheet flow area” means as provided in the term “shallow flooding.”
2. “Special flood hazard area (SFHA)” means an area in the floodplain subject to a one (1%) percent or greater chance of flooding in any given year. It is shown on FIRM as Zone A, AO, AE, or AH.
3. “Start of construction” means the date the building permit was issued for substantial improvement and other proposed new development, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within one hundred eighty (180) days from the date of the permit. The “actual start” means either the first (1st) 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 flood control improvements, 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 (1st) 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.
4. “Structure” means a structure as defined in EGMC Title 23.
5. “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 (50%) percent of the market value of the structure before the damage occurred.
6. “Substantial improvement” means any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds fifty (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:
a. Any project for improvement of a structure to correct existing violations or 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
T. “T” Definitions. Reserved for future use.
1. “Unmapped area” means any area that is located outside of a special flood hazard area.
1. “Violation” means the failure of a structure or other development to be fully compliant with this chapter. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in this chapter is presumed to be in violation until such time as that documentation is provided.
1. “Water surface elevation” means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum (NAVD) of 1988, or other datum, of floods of various magnitudes and frequencies in the floodplains of riverine areas.
2. “Watercourse” means a lake, river, creek, stream, wash, arroyo, channel, or other topographic feature on or over which waters flow at least periodically. “Watercourse” includes specifically designated areas in which substantial flood damage may occur.
X. “X” Definitions. Reserved for future use.
Y. “Y” Definitions. Reserved for future use.
Z. “Z” Definitions. Reserved for future use. [Ord. 14-2017 §3 (Exh. A), eff. 6-23-2017; Ord. 15-2016 §5 (Exh. C), eff. 9-23-2016]
A. Designation of the Floodplain Administrator. The Public Works Director, or their designee, is hereby appointed to administer, implement, and enforce this chapter.
1. Permit Review. Review all development permits to determine that:
a. Permit requirements of this chapter have been satisfied.
b. All other required State and Federal permits have been obtained.
c. The proposed development or encroachment does not adversely affect the carrying capacity of areas where base flood elevations have been determined but a floodway has not been designated. This means 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 at any point within the City.
d. Any necessary letters of map revision (LOMRs) shall be approved prior to the issuance of building permits. Building permits shall not be issued based on conditional letters of map revision (CLOMRs). Approved CLOMRs will allow for the construction of proposed flood control improvements, land preparation, and/or other exclusions as specified in the “Start of construction” definition.
a. Using FEMA publication FEMA P-758, “Substantial Improvement/Substantial Damage Desk Reference,” develop detailed procedures for identifying and administering requirements for substantial improvement and substantial damage, to include defining market value.
b. Assure procedures are coordinated with other departments/divisions and implemented by City staff.
3. Determine when substantial progress has been made on flood control projects for local projects relative to EGMC Section 23.42.040 (Flood combining district).
4. Review, Use, and Development of Other Base Flood Data. When base flood elevation data has not been provided in accordance with EGMC Section 16.50.040(B) (Basis for Establishing the Areas of Special Flood Hazard), the Floodplain Administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a Federal or State agency, or other source, in order to administer EGMC Section 16.50.060 (Provisions for Flood Hazard Reduction).
Note: For FEMA floodplain mapped areas, a base flood elevation may be obtained using one (1) of two (2) methods from the FEMA publication FEMA 265, “Managing Floodplain Development in Approximate Zone A Areas – A Guide for Obtaining and Developing Base (100-year) Flood Elevations,” dated July 1995. Final decision of method used shall be at the sole discretion of the Floodplain Administrator.
5. Notification of Other Agencies.
ii. Submit evidence of such notification to FEMA; and
b. Base Flood Elevation Changes Due to Physical Alterations to Floodplains Shown on FIRMs.
i. At substantial completion of improvements (flood control improvements, land preparation and/or other exclusions as specified in the “Start of construction” definition) as determined by the Floodplain Administrator, the Floodplain Administrator will submit to FEMA for a letter of map revision (LOMR). For private development projects, the developer shall submit to the Floodplain Administrator all necessary technical or scientific data required as part of the LOMR process prior to submittal to FEMA.
ii. All LOMRs for flood control projects shall be approved prior to the issuance of building permits. Building permits must not be issued based on conditional letters of map revision (CLOMRs). Approved CLOMRs will allow for the construction of proposed flood control improvements, land preparation and/or other exclusions as specified in the “Start of construction” definition.
c. Base Flood Elevation Changes Due to Physical Alterations to Unmapped Areas. No CLOMR or LOMR is required to be submitted to FEMA; however, no building permits shall be issued until the applicable requirements of EGMC Section 16.50.060(C) have been satisfied as determined by the Floodplain Administrator.
d. Changes in Corporate Boundaries. Notify FEMA in writing whenever the corporate boundaries have been modified by annexation or other means and include a copy of a map of the community clearly delineating the new corporate limits.
6. Documentation of Floodplain Development. Obtain and maintain for public inspection and make available as needed the following:
a. Certification required by EGMC Section 16.50.060(A)(3)(a) (Residential Construction);
b. Certification required by EGMC Section 16.50.060(A)(3)(b) (Nonresidential Construction);
c. Certification required by EGMC Section 16.50.060(A)(3)(c) (Flood Openings);
d. Certification of elevation required by EGMC Section 16.50.060(C) (standards for subdivisions and other proposed development);
e. Certification required by EGMC Section 16.50.060(D)(2) (floodways).
7. Map Determination. Make interpretations, where needed, as to the exact location of the boundaries of the areas of special flood hazard, 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 EGMC Section 16.50.050(D) (Appeals).
8. Remedial Action. Take action to remedy violations of this chapter as specified in EGMC Section 16.50.040(C) (Compliance).
9. Planning. Assure the City’s General Plan and Zoning Code are consistent with floodplain management objectives herein. [Ord. 14-2017 §3 (Exh. A), eff. 6-23-2017; Ord. 15-2016 §5 (Exh. C), eff. 9-23-2016]
A. Lands to Which This Chapter Applies. This chapter shall apply to all areas of special flood hazards within the City of Elk Grove.
B. Basis for Establishing the Areas of Special Flood Hazard. The areas of special flood hazard identified by the Federal Emergency Management Agency (FEMA) in the “Flood Insurance Study (FIS) for Sacramento County, California, and Incorporated Areas dated August 16, 2012,” with accompanying Flood Insurance Rate Maps (FIRMs) and Flood Boundary and Floodway Maps (FBFMs), dated August 16, 2012, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this chapter. This FIS and attendant mapping are the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter and which are recommended to the City Council by the Floodplain Administrator. The Flood Insurance Studies and FIRMs are on file at the Public Works Department at the City.
C. 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. Violation of the requirements (including violations of conditions and safeguards) shall constitute a misdemeanor. Nothing herein shall prevent the City from taking such lawful action as is necessary to prevent or remedy any violation.
D. Abrogation and Greater Restrictions. This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another chapter, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
2. Liberally construed in favor of the City Council; and
F. 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 man-made or natural causes. This chapter does not imply that land outside the areas of special flood hazards 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 Council, any officer or employee thereof, the State of California, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. [Ord. 14-2018 §2, eff. 8-10-2018; Ord. 14-2017 §3 (Exh. A), eff. 6-23-2017; Ord. 15-2016 §5 (Exh. C), eff. 9-23-2016]
A. Application. A floodplain development permit shall be obtained before any construction or other development within any area of special flood hazard established in EGMC Section 16.50.040(B) (Basis for Establishing the Areas of Special Flood Hazard). Application for a floodplain development permit shall be made on forms furnished by the City. The applicant shall provide the following minimum information:
a. Location, dimensions, and elevation of the area in question, existing or proposed structures, storage of materials and equipment, and their location;
e. Base flood elevation (BFE) information as specified in EGMC Section 16.50.040(B) (Basis for Establishing the Areas of Special Flood Hazard) or EGMC Section 16.50.030(B)(4) (Review, Use, and Development of Other Base Flood Data);
f. Proposed elevation, in relation to mean sea level, of the lowest floor (including basement) of all structures; and
g. Proposed elevation in relation to mean sea level to which any nonresidential structure will be flood-proofed, as required in EGMC Section 16.50.060(A)(3)(b) (Nonresidential Construction) and detailed in FEMA Technical Bulletin TB 3-93.
2. Certification from a registered civil engineer or architect that the nonresidential flood-proofed building meets the flood-proofing criteria in EGMC Section 16.50.060(A)(3)(b) (Nonresidential Construction).
3. For a crawl space foundation, location and total net area of foundation openings as required in EGMC Section 16.50.060(A)(3)(c) (Flood Openings) and detailed in FEMA Technical Bulletins 1-93 and 7-93.
5. All appropriate certifications listed in EGMC Section 16.50.030(B)(6) (Documentation of Floodplain Development).
B. Types of Development Allowed in Areas of Special Flood Hazard. Consistent with the City’s General Plan, a floodplain development permit shall only be issued for the following types of development:
1. Nonhabitable accessory structures as provided in EGMC Section 16.50.060(A)(4);
2. New subdivisions and other proposed development pursuant to the provisions of EGMC Section 16.50.060(C).
C. Designated Approving Authority. Generally, the Floodplain Administrator shall be the designated approving authority for floodplain development permits; however, when a floodplain development permit is combined with a tentative subdivision map, tentative parcel map, design review, or other entitlement required by EGMC Title 23 (Zoning), the designated approving authority shall be the same as for the other required approvals.
D. Appeals. Appeals of the decision on a floodplain development permit shall be conducted pursuant to the following provisions:
1. For decisions made by the Floodplain Administrator, appeals shall be pursuant to EGMC Chapter 1.11;
2. For decisions made by the Planning Commission, Zoning Administrator or Development Services Director, appeals shall be pursuant to EGMC Section 23.14.060. [Ord. 14-2017 §3 (Exh. A), eff. 6-23-2017; Ord. 15-2016 §5 (Exh. C), eff. 9-23-2016]
A. Standards of Construction. In all areas of special flood hazards, the following standards are required:
1. Anchoring. All new construction and substantial improvements of structures, including manufactured homes and tanks (e.g., water, propane), shall be adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Permanent structures and caskets for burial located within cemeteries shall also meet this anchoring requirement.
a. With flood-resistant materials, and utility equipment resistant to flood damage for areas below the base flood elevation;
c. 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; and
d. Within Zone AH or AO, so that there are adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.
3. Elevation and Flood-Proofing of Improvements to Existing Structures. The following shall apply to remodels of or improvements to existing structures already located within areas of special flood hazard.
a. Residential Construction. When new square footage is proposed for an existing residential structure that is already constructed in an area of special flood hazard, the lowest floor, including basement, of the new square footage shall be in conformance with the following standards. Upon the completion of the new square footage, the elevation of the new floor, including basement, shall be certified by a registered civil engineer or licensed land surveyor to be properly elevated. Such certification and verification shall be provided to the Floodplain Administrator.
i. In AE and AH, elevated to one (1' 0”) foot above the base flood elevation (BFE).
ii. In an AO Zone, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at least two (2') feet above the highest adjacent grade if no depth number is specified.
iii. In an A Zone, without BFEs specified on the FIRM, elevated to or above the base flood elevation, as determined under EGMC Section 16.50.030(B)(4) (Review, Use, and Development of Other Base Flood Data).
b. Nonresidential Construction. When new square footage is proposed for an existing nonresidential structure (commercial, office, or industrial development) that is already constructed in an area of special flood hazard, all new improvements shall either be elevated to conform with subsection (A)(3)(a) of this section (Residential Construction); or
i. Be flood-proofed, together with attendant utility and sanitary facilities, below the elevation recommended under subsection (A)(3)(a) of this section, so that the structure is watertight with walls substantially impermeable to the passage of water;
iii. Be certified by a registered civil engineer or architect that the standards of subsections (A)(3)(b)(i) and (ii) of this section are satisfied. Such certification will be provided to the Floodplain Administrator.
c. Flood Openings. All new construction and substantial improvements of structures with fully enclosed areas below the lowest floor (excluding basements) that are usable solely for parking of vehicles, building access, or storage, and which 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 meet the following minimum criteria:
i. For non-engineered openings:
(A) Have a minimum of two (2) openings on different sides having a total net area of not less than one (1 in2) square inch for every one (1 ft2) square foot of enclosed area subject to flooding;
(B) The bottom of all openings shall be no higher than one (1') foot above grade;
(C) Openings may be equipped with screens, louvers, valves, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwater; and
(D) Buildings with more than one (1) enclosed area must have openings on exterior walls for each area to allow floodwater to directly enter; or
4. New Non-Habitable Accessory Structures.
i. A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry of floodwaters. See subsection (A)(3)(c) of this section (Flood Openings). Areas of the garage below the BFE must be constructed with flood-resistant materials. See subsection (A)(2) of this section (Construction Materials and Methods).
ii. A garage attached to a nonresidential structure must meet the above requirements or be dry flood-proofed. For guidance on below-grade parking areas, see FEMA Technical Bulletin TB-6.
b. Detached Garages and Small Accessory Buildings. An accessory structure used solely for parking or other types of small accessory buildings, as defined in EGMC Section 16.50.020 (Definitions), may be constructed such that its floor is below the base flood elevation (BFE), provided the structure is designed and constructed in accordance with the following requirements:
i. Use of the accessory structure must be limited to parking or limited storage;
ii. The portions of the accessory structure located below the BFE must be built using flood-resistant materials;
iii. The accessory structure must be adequately anchored to prevent flotation, collapse, and lateral movement;
iv. Any mechanical and utility equipment in the accessory structure must be elevated or flood-proofed to or above the BFE;
v. No hazardous materials shall be stored within the structure;
vi. The accessory structure must comply with floodplain encroachment provisions in subsection (D) of this section (Floodways);
vii. The accessory structure must be designed to allow for the automatic entry of floodwaters in accordance with subsection (A)(3)(c) of this section (Flood Openings); and
viii. Detached garages and accessory structures not meeting the above standards must be constructed in accordance with all applicable standards in subsection (A) of this section (Standards of Construction).
c. Other Accessory Structures. Other accessory structures, including but not limited to landscape features, pools and spas, patio covers, gazebos, tanks, and lean-tos, as defined in EGMC Section 23.100.020(A)(2) (Accessory Structure), may be constructed such that their floor is below the base flood elevation (BFE), provided the structure is designed and constructed in accordance with the following requirements:
i. The structure cannot be permanently occupied;
v. The accessory structure must comply with floodplain encroachment provisions in subsection (D) of this section (Floodways);
vi. The accessory structure must be designed to allow for the automatic entry of floodwaters in accordance with subsection (A)(3)(c) of this section (Flood Openings).
C. Standards for Subdivisions and Other Proposed New Development.
1. All new subdivision proposals and other proposed new development, including proposals for manufactured home parks and subdivisions, shall:
a. Identify the special flood hazard areas (SFHAs), if necessary, and base flood elevations (BFEs).
b. Identify the elevations of lowest floors of all proposed structures and pads on the final plans and/or elevation certificate certified from a registered civil engineer or architect.
c. Provide a buildable area outside the area of special flood hazard of sufficient size to accommodate a residence and associated structures.
d. In special flood hazard areas, elevate the lowest finished floor at least one and one-half (1' 6") feet above the base flood elevation. Building pads for slab-on-grade construction shall be at least one and one-half (1' 6") feet above the base flood elevation and the lowest finished floor shall be at least one and one-half (1' 6") feet above the base flood elevation.
e. In unmapped areas, elevate the lowest finished floor at least two (2' 0") feet above the base flood elevation. Building pads for slab-on-grade construction shall be at least two (2' 0") feet above the base flood elevation and the lowest finished floor shall be at least two (2' 0") feet above the BFE.
f. In a SFHA, if the proposed site is to be elevated above the BFE by placement of fill, an application for a conditional letter of map revision, based on fill (CLOMR-F), shall be submitted to FEMA.
3. All subdivision proposals and other proposed development shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.
5. Vehicular access to the buildable area(s) of the proposed development shall be at or above the ten (10) year flood elevation.
6. While the use of fill to create buildable area is strongly discouraged by City policy, should it be allowed, there shall be no net increase to the water surface elevation adjacent to, downstream, and upstream of the development, as determined by the City. Other improvements may be required as part of the proposed project. A conditional letter of map revision (CLOMR) issued by FEMA shall be required prior to grading permit issuance, unless only a LOMR is required. A letter of map revision (LOMR) issued by FEMA shall be required prior to acceptance of the improvements or issuance of the first (1st) building permit as determined by the Floodplain Administrator.
D. Floodways. Since floodways are an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following additional provisions apply:
1. Until a regulatory floodway is adopted by FEMA, no new construction, substantial development, or other development (including fill) shall be permitted within Zones A, AE and AH, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other development, will not increase the water surface elevation of the base flood at any point within the City.
2. Within an adopted regulatory floodway, the City shall prohibit encroachments, including fill, new construction, substantial improvements, and other development, unless certification by a registered civil engineer is provided demonstrating that the proposed encroachment shall not result in any increase in flood levels during the occurrence of the base flood discharge. [Ord. 14-2017 §3 (Exh. A), eff. 6-23-2017; Ord. 15-2016 §5 (Exh. C), eff. 9-23-2016]