Chapter 2.05
FLOOD HAZARD PREVENTION1

Sections:

Article I. Definitions

2.05.010    Definitions.

Article II. General Provisions

2.05.020    Lands to which this chapter applies.

2.05.030    Basis for establishing the areas of special flood hazard.

2.05.040    Penalties for noncompliance.

2.05.050    Abrogation and greater restrictions.

2.05.060    Interpretation.

2.05.070    Warning and disclaimer of liability.

Article III. Administration

2.05.080    Establishment of development permit.

2.05.090    Designation of the administration.

2.05.100    Duties and responsibilities of the administrator.

Article IV. Provisions for Flood Hazard Reduction

2.05.110    General standards.

2.05.120    Anchoring.

2.05.130    Construction materials and methods.

2.05.140    Utilities.

2.05.150    Subdivision proposals.

2.05.160    Review of building permits.

2.05.170    Specific standards.

2.05.180    Residential construction.

2.05.190    Nonresidential construction.

2.05.200    Manufactured homes.

2.05.210    Recreational vehicles.

2.05.220    Crawlspaces.

2.05.230    AE and A1-30 zones with base flood elevations but no floodways.

2.05.240    Standards for shallow flooding areas (AO zones).

2.05.250    Encroachments.

Article I. Definitions

2.05.010 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.

“Area of shallow flooding” means a designated AO zone on the flood insurance rate map (FIRM). The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident.

“Area of special flood hazard” means the land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year.

“Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year. Also referred to as the “100-year flood.”

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

“Development” means any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations located within the area of special flood hazard.

“Development permit” means a generic term that includes any and all reviews, licenses, authorizations, approvals, permits, etc., that allow the city a right of review on proposals that ultimately result in a physical alteration to the environment.

“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 of runoff of surface water from any source.

“Flood insurance rate map (FIRM)” means the official map on which the Federal Insurance Administration had delineated both the areas of special flood hazard and the risk premium zones applicable to the community.

“Flood insurance study” means the official report provided by the Federal Insurance Administration that includes flood profiles, the flood boundary-floodway map, and the water surface elevation of the base flood.

“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 (provided there are adequate flood ventilation openings).

“Manufactured home” means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For floodplain management purposes, the term “manufactured home” also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than 180 consecutive days. For insurance purposes, the term “manufactured home” does not include park trailers, travel trailers, and other similar vehicles.

“Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

“New construction” means structures for which the “start of construction” commenced on or after the effective date of the ordinance codified in this chapter.

“Recreational vehicle” means a vehicle:

(1) Built on a single chassis;

(2) Four hundred square feet or less when measured at the largest horizontal projection;

(3) Designed to be self-propelled or permanently towable by a light duty truck; and

(4) Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

“Start of construction” includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement or other improvement was within 180 days of the permit date. The “actual start” means either 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 state 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, foots, piers or foundation or the erection of temporary forms; nor does it include the installation on a property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure.

“Structure” means a walled and roofed building including a gas or liquid storage tank that is principally above ground.

“Substantial improvements” means any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure either:

(1) Before the improvement or repair is started; or

(2) If the structure has been damaged and is being restored, before the damage occurred. For the purpose of this definition, “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.

The term can exclude:

(3) Any project for improvement of a structure to correct pre-cited violations of state or local health, sanitary, or safety code specifications which have been previously identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or

(4) Any alteration of a structure listed in the National Register of Historic Places or a State Inventory of Historic Places.

“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. (Ord. 2016-02 § 1; Ord. 2004-18 § 1)

Article II. General Provisions

2.05.020 Lands to which this chapter applies.

This chapter shall apply to all areas of special flood hazards within the jurisdiction of the city of Wenatchee. This chapter shall only apply to those areas where sufficient information is available to properly implement these regulations. (Ord. 2016-02 § 1; Ord. 2004-18 § 2.1)

2.05.030 Basis for establishing the areas of special flood hazard.

The areas of special flood hazard identified by the Federal Insurance Administration in scientific and engineering reports entitled “The Flood Insurance Study for the City of Wenatchee,” dated January 6, 1996, and subsequent Letter of Map Amendment (LOMR) dated May 13, 1996, and “The Flood Insurance Study for Chelan County,” dated February 4, 1981, and revised September 30, 2004, and any revisions thereto, with accompanying flood insurance maps, is hereby adopted by reference and declared to be a part of this chapter. The flood insurance study is on file at 1350 McKittrick Street. (Ord. 2016-02 § 1; Ord. 2004-18 § 2.2)

2.05.040 Penalties for noncompliance.

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 provisions of this chapter by failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute a code violation. Any person who violates this chapter or fails to comply with any of its requirements shall pay all costs and expenses involved in this case. Nothing herein contained shall prevent the city of Wenatchee from taking such other lawful action as is necessary to prevent or remedy violations. (Ord. 2016-02 § 1; Ord. 2004-18 § 2.3)

2.05.050 Abrogation and greater restrictions.

This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. (Ord. 2016-02 § 1; Ord. 2004-18 § 2.4)

2.05.060 Interpretation.

In the interpretation and application of this chapter, all provisions shall be:

(1) Considered as minimum requirements;

(2) Liberally construed in favor of the governing body; and

(3) Deemed neither to limit or repeal any other powers granted under state statute. (Ord. 2016-02 § 1; Ord. 2004-18 § 2.5)

2.05.070 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 hazards or uses permitted within such areas will be free from flooding and flood damages. This chapter shall not create liability on the part of the city of Wenatchee, any officer or employee thereof, for any flood damage that results from reliance on this chapter or any administrative decision lawfully made herein. (Ord. 2016-02 § 1; Ord. 2004-18 § 2.6)

Article III. Administration

2.05.080 Establishment of development permit.

(1) Development Permit Required. A development permit shall be obtained before construction or development begins within an area of special flood hazard established in WCC 2.05.030. The permit shall be for all structures, including manufactured homes, as set forth in WCC 2.05.010, Definitions, and for all development including fill and other activities, also as set forth in WCC 2.05.010, Definitions.

(2) Application for Development Permit. Application for a development permit shall be made on forms furnished by the local administration and may include, but not be limited to: plans in duplicate drawn to scale showing the nature, location, dimensions and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing. Specifically, the following information is required:

(a) Elevation, in relation to adjacent grade, of the lowest floor (including basement) of all structures;

(b) Elevation in relation to adjacent grade to which any structure has been floodproofed;

(c) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in WCC 2.05.190; and

(d) Description of the extent to which a watercourse will be altered or relocated as a result of proposed development. (Ord. 2016-02 § 1; Ord. 2004-18 § 3.1)

2.05.090 Designation of the administration.

The planning director, building official, or their designee is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. (Ord. 2016-02 § 1; Ord. 2004-18 § 3.2)

2.05.100 Duties and responsibilities of the administrator.

Duties of the administrator shall include, but not be limited to:

(1) Permit Review.

(a) Review all development permits to determine that the permit requirements of this chapter have been satisfied.

(b) Review all development permits to determine that all necessary permits have been obtained from those federal, state and local governmental agencies from which prior approval is required.

(2) Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with WCC 2.05.030, Basis for establishing the areas of special flood hazard, the administrator shall obtain, review and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer WCC 2.05.170 through 2.05.230, Specific standards, and WCC 2.05.240, Standards for shallow flooding areas (AO zones).

(3) Information to Be Obtained and Maintained.

(a) Where base flood elevation data is provided through the flood insurance study or required as in subsection (2) of this section, obtain and record the actual (as built) elevation (above adjacent grade in Zone AO; above mean sea level in Zones A, AE) of the lowest floor (including basement) of all new or substantially improved structures, and whether or not the structure contains a basement.

(b) For all new or substantially improved floodproofed nonresidential structures where base flood elevation data is provided through FIS, FIRM, or as required in subsection (2) of this section:

(i) Verify and record the actual elevation (above adjacent grade in AO zones and above mean sea level in Zones A, AE); and

(ii) Maintain the floodproofing certifications required in WCC 2.05.080(2)(c).

(c) Maintain for public inspection all records pertaining to the provisions of this chapter.

(4) Alteration of Watercourses.

(a) Notify adjacent communities and the Washington State Department of Ecology prior to any alteration or relocation of a watercourse and submit evidence of such notification to the Federal Insurance Administration.

(b) Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood-carrying capacity is not diminished.

(5) Interpretation of FIRM Boundaries. Make interpretation where needed, as to exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation. Such appeals shall be granted consistent with the standards of Section 60.6 of the Rules and Regulations of the National Flood Insurance Program (44 CFR 59-76). (Ord. 2016-02 § 1; Ord. 2004-18 § 3.3)

Article IV. Provisions for Flood Hazard Reduction

2.05.110 General standards.

See WCC 2.05.110 through 2.05.160. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.1)

2.05.120 Anchoring.

(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.

(2) All manufactured homes must likewise be anchored to prevent flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors (reference FEMA’s “Manufactured Home Installation in Flood Hazard Areas” guidebook for additional techniques). (Ord. 2016-02 § 1; Ord. 2004-18 § 4.1-1)

2.05.130 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) Electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.1-2)

2.05.140 Utilities.

(1) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system. Water wells shall be located on high ground that is not in the floodway;

(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. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.1-3)

2.05.150 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, electric, and water systems located and constructed to minimize or eliminate flood damage;

(3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and

(4) Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed development which contain at least 50 lots or five acres (whichever is less). (Ord. 2016-02 § 1; Ord. 2004-18 § 4.1-4)

2.05.160 Review of building permits.

Where elevation data is not available either through the flood insurance study or from another authoritative source (WCC 2.05.100(2)), applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.1-5)

2.05.170 Specific standards.

In all areas of special flood hazards where base flood elevation data has been provided as set forth in WCC 2.05.030, Basis for establishing the areas of special flood hazard, or WCC 2.05.100(2), Use of Other Base Flood Data, the provisions of WCC 2.05.180 through 2.05.230 are required. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.2)

2.05.180 Residential construction.

(1) New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the base flood elevation.

(2) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or 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 criteria:

(a) 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.

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

(c) Openings may be equipped with screens, louvers, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.2-1)

2.05.190 Nonresidential construction.

New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall have the lowest floor, including basement, elevated to the level of the base flood elevation; or together with attendant utility and sanitary facilities, shall:

(1) Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;

(2) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;

(3) Be certified by a registered professional engineer or architect that the design and method of construction are in accordance with acceptable standards of practice for meeting provisions of this subsection based on their development and/or review of the structure design, specifications and plans. Such certifications shall be provided to the official as set forth in WCC 2.05.100(3)(b).

(4) Nonresidential structures that are elevated, not floodproofed, must meet the same standard for space below lowest floor as described in WCC 2.05.180(2).

(5) Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (e.g., a building constructed to the base flood level will be rated as one foot below that level). (Ord. 2016-02 § 1; Ord. 2004-18 § 4.2-2)

2.05.200 Manufactured homes.

All manufactured homes to be placed or substantially improved within the floodplain shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the base flood elevation; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of WCC 2.05.120(2). (Ord. 2016-02 § 1; Ord. 2004-18 § 4.2-3)

2.05.210 Recreational vehicles.

Recreational vehicles placed on sites are required to either:

(1) Be on site for fewer than 180 consecutive days; or

(2) Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or

(3) Meet the requirements of WCC 2.05.200 and the elevation and anchoring requirements for manufactured homes. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.2-3)

2.05.220 Crawlspaces.

Crawlspaces are commonly used as a method of elevating buildings in SFHAs to or above the BFE. General NFIP requirements that apply to all crawlspaces that have enclosed areas or floors below the BFE include the following:

(1) The building must be designed and adequately anchored to resist flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effect of buoyancy. Hydrostatic loads and the effects of buoyancy can usually be addressed through the required openings discussed below. Because of hydrostatic loads, crawlspace construction is not recommended in areas with flood velocities greater than five feet per second unless the design is reviewed by a qualified design professional, such as a registered architect or professional engineer.

(2) The crawlspace is an enclosed area below the BFE and, as such, must have openings that equalize hydrostatic pressures by allowing for the automatic entry and exit of floodwaters. The bottom of each flood vent opening can be no more than one foot above the lowest adjacent exterior grade. (For guidance on flood openings, see Technical Bulletin 1-93, Openings in Foundation Walls.)

(3) Portions of the building below the BFE must be constructed with materials resistant to flood damage. This includes not only the foundation walls of the crawlspace used to elevate the building, but also any joists, insulation, or other materials that extend below the BFE. The recommended construction practice is to elevate the bottom of joists and all insulation above BFE.

(4) Any building utility systems within the crawlspace must be elevated above the BFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions. Duct work in particular must either be placed above the BFE or sealed from floodwaters.

(5) In addition to the above requirements, the following provisions apply to below-grade crawlspaces:

(a) The interior grade of a crawlspace below the BFE must not be more than two feet below the lowest adjacent exterior grade (LAG).

(b) The height of the below-grade crawlspace, measured from the interior grade of the crawlspace to the top of the crawlspace foundation wall, must not exceed four feet at any point.

(c) There must be an adequate drainage system that removes floodwaters from the interior area of the crawlspace. The enclosed area should be drained within a reasonable time after a flood event. Possible options include natural drainage through porous, well-drained soils and drainage systems such as perforated pipes, drainage tiles, or gravel or crushed stone drainage by gravity of mechanical means.

(d) The velocity of floodwaters at the site should not exceed five feet per second for any crawlspace.

(e) Below-grade crawlspace construction in accordance with the requirements listed above will not be considered basements.

(6) All crawlspace construction shall conform to FEMA Technical Bulletin 11-01, Crawlspace Construction for Buildings Located in Special Flood Hazard Areas. (Ord. 2016-02 § 1; Ord. 2007-29 § 1; Ord. 2004-18 § 4.2-4)

2.05.230 AE and A1-30 zones with base flood elevations but no floodways.

In areas with base flood elevation, but no regulatory floodway has been designated, no new construction, substantial improvements, or other development (including fill) shall be permitted within Zones A1-30 and AE on the community 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 foot at any point within the community. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.2-4)

2.05.240 Standards for shallow flooding areas (AO zones).

Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these zones range from one to three feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. In these areas, the following provisions apply:

(1) New construction and substantial improvements of residential structures and manufactured homes within AO zones shall have the lowest floor (including basement) elevated above the highest grade adjacent to the building, to or above the depth number specified on the FIRM (at least two feet if no depth number is specified).

(2) New construction and substantial improvements of nonresidential structures within AO zones shall either:

(a) Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, to or above the depth number specified on the FIRM (at least two feet if no depth number is specified); or

(b) Together with attendant utility and sanitary facilities, be completely floodproofed to or above the level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capacity of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect as in WCC 2.05.190(3).

(3) Require adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.

(4) Recreational vehicles placed on sites within AO zones on the community’s FIRM are required to either:

(a) Be on site for fewer than 180 consecutive days; or

(b) Be fully licensed and ready for highway use, on its wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or

(c) Meet the requirements of subsections (1) and (3) of this section and the anchoring requirements for manufactured homes of WCC 2.05.120. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.3)

2.05.250 Encroachments.

The cumulative effect of any proposed development, when combined with all other existing and anticipated development, shall not increase the water surface elevation of the base flood more than one foot at any point. (Ord. 2016-02 § 1; Ord. 2004-18 § 4.4)


1

Prior legislation: Ord. 2259.