Chapter 15.30 FLOOD DAMAGE PREVENTION

A. The flood hazard areas of the city of Toppenish 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 may be caused by the cumulative effect of obstructions in areas of special flood hazard that 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. 2021-03 § 1, 2021; Ord. 2007-12 § 1.1, 2007).

15.30.020 Statement of purpose.

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

A. To protect human life and health;

B. To minimize expenditure of public money and 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 flood hazard areas;

F. To help maintain a stable tax base by providing for the sound use and development of flood hazard areas to minimize blight areas caused by flooding;

G. To notify potential buyers that the property is in a special flood hazard area;

H. To notify those who occupy special flood hazard areas that they assume responsibility for their actions; and

I. To participate in and maintain eligibility for flood insurance and disaster relief. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 1.2, 2007).

15.30.030 Methods of reducing flood losses.

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

A. Restricting or prohibiting development that is dangerous to health, safety, and property due to water or erosion hazards, or which results in damaging increases in erosion or in flood heights or velocities;

B. Requiring that uses vulnerable to floods 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 floodwaters;

D. Controlling filling, grading, dredging, and other development which may increase flood damage; and

E. Preventing or regulating the construction of flood barriers that unnaturally divert floodwaters or may increase flood hazards in other areas. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 1.3, 2007).

15.30.040 Definitions.

Unless specifically defined below, terms or phrases used in this chapter shall be interpreted to give them the meaning they have in common usage and to give this chapter its most reasonable application.

A. “Alteration of watercourse” means any action that will change the location of the channel occupied by water within the banks of any portion of a riverine water body.

B. “Appeal” means a request for a review of the interpretation of any provision of this chapter or a request for a variance.

C. “Area of shallow flooding” means a designated zone AO, AH, AR/AO or AR/AH on a community’s Flood Insurance Rate Map (FIRM) with one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist; where the path of flooding is unpredictable; and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. Also referred to as the sheet flow area.

D. “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. It is shown on the Flood Insurance Rate Map (FIRM) as zone A, AO, AH, A1-30, AE, A99, or AR. “Special flood hazard area” is synonymous in meaning with the phrase “area of special flood hazard.”

E. “ASCE 24” means the most recently published version of the ASCE 24, Flood Resistant Design and Construction, published by the American Society of Civil Engineers.

F. “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”).

G. “Base flood elevation (BFE)” means the elevation to which floodwater is anticipated to rise during the base flood.

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

I. “Building Code” means the International Building Code and the International Residential Building Code as adopted in Chapter 15.01 TMC.

J. “Critical facility” means a facility for which even a slight chance of flooding might be too great. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and emergency response installations, and installations that produce, use, or store hazardous materials or hazardous waste.

K. “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 equipment or materials located within the area of special flood hazard.

L. “Elevated building” means, for insurance purposes, a nonbasement building that has its lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings, or columns.

M. “Elevation certificate” means an administrative tool of the National Flood Insurance Program (NFIP) that can be used to provide elevation information, to determine the proper insurance premium rate and to support a request for a Letter of Map Amendment (LOMA) or Letter of Map Revision based on fill (LOMR-F).

N. “Essential facility” has the same meaning as “essential facility” defined in ASCE 24 Table 1-1 which further identifies building occupancies that are essential facilities.

O. “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 is completed before the effective date of the adopted floodplain management regulations.

P. “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.

Q. “Flood or flooding” means:

1. A general and temporary condition of partial or complete inundation of normally dry land areas from:

a. The overflow of inland or tidal waters; and/or

b. The unusual and rapid accumulation of runoff of surface waters from any source; and/or

c. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection (Q)(1)(b) of this section and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.

2. The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in subsection (Q)(1)(a) of this section.

R. “Flood elevation study” means an examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e., mudflow) and/or flood-related erosion hazards. Also known as a Flood Insurance Study (FIS).

S. “Flood Insurance Rate Map (FIRM)” means the official map of a community on which the Federal Insurance Administrator has delineated both the areas of special hazard and the risk premium zones applicable to the community. A FIRM that has been made available digitally is called a Digital Flood Insurance Rate Map (DFIRM).

T. “Floodplain or flood-prone area” means any land area susceptible to being inundated by water from any source. See also “Flood or flooding.”

U. “Floodplain administrator” means the community official designated by title to administer and enforce the floodplain management regulations.

V. “Floodplain management regulations” means zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances such as floodplain ordinance, grading ordinance, erosion control ordinance and other applications of police power. The term describes such state or local regulations, in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction.

W. “Floodproofing” means any combination of structural and nonstructural additions, changes, or adjustments to structures that reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents. Floodproofed structures are those that have the structural integrity and design to be impervious to floodwater below the base flood elevation.

X. “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 by more than a designated height. Also referred to as a “regulatory floodway.”

Y. “Functionally dependent use” means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and shipbuilding and ship repair facilities, and does not include long-term storage or related manufacturing facilities.

Z. “Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

AA. “Historic structure” means any structure that is:

1. Listed individually in the National Register of Historic Places, which is 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 that 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.

BB. “Lowest floor” means the lowest floor of the lowest enclosed area including the 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 to render the structure in violation of the applicable nonelevation design requirements found at TMC 15.30.160(A)(2) (i.e., provided there are adequate flood ventilation openings).

CC. “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.

DD. “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.

EE. “Mean sea level” means, for purposes of the National Flood Insurance Program, the vertical datum to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced.

FF. “New construction” means, for the purposes of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial Flood Insurance Rate Map or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new construction” means structures for which the start of construction commenced on or after the effective date of the ordinance codified in this chapter and includes any subsequent improvements to such structures.

GG. “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 the ordinance codified in this chapter.

HH. “Reasonably safe from flooding” means development that is designed and built to be safe from flooding based on consideration of current flood elevation studies, historical data, high water marks and other reliable data known to the community. In unnumbered A zones where flood elevation information is not available and cannot be obtained by practicable means, “reasonably safe from flooding” means that the lowest floor is at least two feet above the highest adjacent grade.

II. “Recreational vehicle” means a vehicle that is:

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.

JJ. “Start of construction” includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement or other improvement was within 180 days of the permit issuance 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 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 parts of a building, whether or not that alteration affects the external dimensions of the building.

KK. “Structure” means, for flood management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.

LL. “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.

MM. “Substantial improvement” means any addition, repair, reconstruction, rehabilitation or other improvements 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 that have incurred substantial damage, regardless of the actual repair work performed. The term excludes:

1. Any project for improvement of a structure to correct previously identified existing violations of state or local health, sanitary, or safety code specifications that have been previously identified by the local code enforcement official and that are the minimum necessary to assure safe living conditions; or

2. Any alteration of a historic structure listed on the National Register of Historic Places or a state inventory of historic places, provided the alteration will not preclude the structure’s continued designation as a historic structure.

NN. “Variance” means a grant of relief from the terms of this chapter.

OO. “Water dependent” means a structure for commerce or industry that cannot exist in any other location and is dependent on the water by reason of the intrinsic nature of its operations.

PP. “Water surface elevation” means the height, in relation to the vertical datum utilized in the applicable flood insurance study, of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 2.0, 2007).

15.30.050 Lands to which this chapter applies.

This chapter shall apply to all areas of special flood hazard within the jurisdiction of the city of Toppenish. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 3.1, 2007).

15.30.060 Basis for establishing the areas of special flood hazard.

The areas of special flood hazard identified by the Federal Insurance Administrator in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for the City of Toppenish” dated June 16, 2016, and any revisions thereto, with accompanying Flood Insurance Rate Maps (FIRM) dated November 18, 2009, and any revisions thereto, are hereby adopted by reference and declared to be part of this chapter. The FIS and FIRM are on file at the City of Toppenish, City Hall, 21 West First Avenue, Toppenish, WA 98948. The best available information for flood hazard area identification as outlined in TMC 15.30.130(D) shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under TMC 15.30.130(D). (Ord. 2021-03 § 1, 2021; Ord. 2009-10, 2009; Ord. 2007-12 § 3.2, 2007).

15.30.065 Compliance.

All development within special flood hazard areas is subject to the terms of this chapter and other applicable regulations. (Ord. 2021-03 § 1, 2021).

15.30.070 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. Pursuant to Chapter 2.90 TMC, violations 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 misdemeanor. Any person who violates this chapter or fails to comply with any of its requirements shall upon conviction thereof be fined not more than $1,000 or imprisoned for not more than 90 days, or both, for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent the city of Toppenish from taking such other lawful action as is necessary to prevent or remedy any violation. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 3.3, 2007).

15.30.080 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. 2021-03 § 1, 2021; Ord. 2007-12 § 3.4, 2007).

15.30.090 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. 2021-03 § 1, 2021; Ord. 2007-12 § 3.5, 2007).

15.30.100 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 or flood damages. This chapter shall not create liability on the part of the city of Toppenish, any officer or employee thereof, or the Federal Insurance Administration for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 3.6, 2007).

15.30.110 Development permit required – Fee.

A flood development permit shall be obtained before construction or development begins within any special flood hazard area established in TMC 15.30.060. The permit shall be required for all structures, including manufactured homes, and for all development including fill and other activities as set forth in TMC 15.30.040. The fee for a flood development permit shall be as established by resolution of the city council, as amended from time to time. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 4.1, 2007).

15.30.115 Application for development permit.

Application for a development permit shall be made on forms furnished by the city of Toppenish 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. Proposed elevation in relation to mean sea level of the lowest floor, including basements of all structures, recorded on a current elevation certificate with Section B completed by the floodplain administrator;

B. Proposed elevation in relation to mean sea level to which any structure has been floodproofed;

C. Where a structure is to be floodproofed, certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet floodproofing criteria in TMC 15.30.160(B);

D. Description of the extent to which a watercourse will be altered or relocated as a result of the proposed development;

E. Where development is proposed in a floodway, an engineering analysis indicating no rise of the base flood elevation; and

F. Any other such information that may be reasonably required by the floodplain administrator to review the application. (Ord. 2021-03 § 1, 2021. Formerly 15.30.110(B)).

15.30.120 Designation of the floodplain administrator.

The city manager is hereby appointed to administer, implement and enforce this chapter by granting or denying development permit applications in accordance with its provisions. The floodplain administrator may delegate the authority to implement the provisions of this chapter. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 4.2, 2007).

15.30.130 Duties and responsibilities of the floodplain administrator.

Duties of the floodplain administrator 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 those 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 TMC 15.30.180(A) are met.

4. Review all development permits to determine if the proposed development site is reasonably safe from flooding.

B. The floodplain administrator shall notify FEMA when annexations occur in the special flood hazard area.

C. The floodplain administrator shall notify FEMA of changes to the base flood elevation within six months of when technical information of such changes becomes available. Such notifications shall include technical or scientific information.

D. When base flood elevation data has not been provided in A zones in accordance with TMC 15.30.060, the floodplain administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from federal, state or other sources, in order to administer TMC 15.30.160 and 15.30.180.

E. Information to Be Obtained and Maintained.

1. Where base flood elevation data is provided through the Flood Insurance Study, FIRM, or required as in subsection D of this section, obtain and record the actual as-built 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 nonresidential structures where base flood elevation data is provided through the FIS, FIRM, or as required in subsection D of this section:

a. Obtain and record the elevation in relation to mean sea level to which the structure was floodproofed; and

b. Maintain the floodproofing certifications required in TMC 15.30.115(C).

3. Maintain for public inspection all records pertaining to the provisions of this chapter.

4. Certification required by TMC 15.30.180(A).

5. Improvement and damage calculations.

F. Whenever a watercourse is to be altered or relocated the floodplain administrator shall:

1. Notify adjacent communities and the Department of Ecology prior to any alteration or relocation of a watercourse and submit evidence of such notification to the Federal Insurance Administrator through appropriate notification means; and

2. Assure that the flood-carrying capacity of the altered or relocated portion of said watercourse is maintained.

G. Interpretations of FIRM boundaries shall be made by the floodplain administrator where needed, as to the exact boundaries of the areas of special flood hazard (e.g., 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).

H. The review building permit applications where elevation data is not available either through the FIS, FIRM, or from another authoritative source pursuant to TMC 15.30.130(D), applications for floodplain development shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes the use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate habitable buildings at least two feet above the highest adjacent grade in these zones may result in higher insurance rates. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 4.3, 2007).

15.30.135 Variances.

A. The variance criteria set forth in this chapter are based on the general principle of zoning law that variances pertain to a piece of property and are not personal in nature. A variance may be granted for a parcel of property with physical characteristics so unusual that complying with the requirements of this chapter would create an exceptional hardship to the applicant or the surrounding property owners. The characteristics must be unique to the property and not be shared by adjacent parcels. The unique characteristic must pertain to the land itself, not to the structure, its inhabitants, or the property owners.

B. It is the duty of the city of Toppenish to help protect its citizens from flooding. This need is so compelling and the implications of the cost of insuring a structure built below the base flood elevation are so serious that variances from the flood elevation or other requirements in this chapter are quite rare. The long-term goal of preventing and reducing flood loss and damage can only be met if variances are strictly limited. Therefore, the variance guidelines provided in this chapter are more detailed and contain multiple provisions that must be met before a variance can be properly granted. The criteria are designed to screen out those situations in which alternatives other than a variance are more appropriate. (Ord. 2021-03 § 1, 2021).

15.30.140 Requirements for variances.

A. Variances shall only be issued:

1. Upon showing of good and sufficient cause;

2. Upon a determination that failure to grant the variance would result in exceptional hardship to the applicant;

3. Upon a determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances;

4. For the repair, rehabilitation, or restoration 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;

5. When a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief; and

6. Upon a showing that the use cannot perform its intended purpose unless it is located or carried out in close proximity to water. This includes only facilities defined in TMC 15.30.040(Y).

B. Variances shall not be issued within any floodway if any increase in flood levels during the base flood discharge would result.

C. 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 elevation, provided the procedures of TMC 15.30.110 through 15.30.130 and 15.30.155 through 15.30.195 have been fully considered. As the lot size increases beyond one-half acre, the technical justification required for issuing the variance increases. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 4.4, 2007).

15.30.145 Variance criteria.

In considering variance applications, the hearing examiner shall consider all technical evaluations, all relevant factors, all standards specified in other sections of this chapter, including:

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 owner;

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 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 time of flood for ordinary and emergency vehicles;

J. The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters 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, water system, and streets and bridges. (Ord. 2021-03 § 1, 2021).

15.30.150 Additional requirements for the issuance of a variance.

A. Any applicant to whom a variance is granted shall be given written notice over the signature of a city official that:

1. The issuance of a variance to construct a structure below the BFE will result in increased premium rates for flood insurance up to amounts as high as $25.00 for $100.00 of insurance coverage; and

2. Such construction below the BFE increases risks to life and property.

B. The floodplain administrator shall maintain a record of all variance actions, including the justification for their issuance.

C. The floodplain administrator shall condition the variance as needed to ensure that the requirements and criteria of this chapter are met.

D. Variances as interpreted in the NFIP are based on the general zoning law principle that they pertain to a physical piece of property; they are not personal and do not pertain to the structure, its inhabitants, or economic or financial circumstances. They primarily address small lots in densely populated residential neighborhoods. As such, variances from flood elevations should be quite rare. (Ord. 2021-03 § 1, 2021).

15.30.155 General standards for provisions for flood hazard reduction.

In all special flood hazard areas, the following standards are required:

A. Anchoring.

1. All new construction and substantial improvements, including those relating to manufactured homes, shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads including the effects of buoyancy.

2. All manufactured homes shall 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, the use of over-the-top or frame ties to ground anchors.

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. Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located 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 floodwaters into the systems.

2. Water wells shall be located on high ground that is not in the floodway pursuant to WAC 173-160-171.

3. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into floodwaters.

4. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

D. Subdivision Proposals and Development. All subdivisions and any new development shall:

1. Be consistent with the need to minimize flood damage;

2. Have public utilities and facilities, such as sewer, gas, electrical, and water systems, located and constructed to minimize or eliminate flood damage;

3. Have adequate drainage provided to reduce exposure to flood damage; and

4. Include as part of the application what the base flood elevation shall be for subdivision proposals and other proposed developments that contain at least 50 lots or five acres, whichever is the lesser.

E. Storage of Materials and Equipment.

1. The storage or processing of materials that could be injurious to human, animal, or plant life if released due to damage from flooding is prohibited in special flood hazard areas.

2. Storage of other material or equipment may be allowed if not subject to damage by floods and if firmly anchored to prevent flotation, or if readily removable from the area within the time available after the issuance of a flood warning. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 5.1, 2007. Formerly 15.30.150).

15.30.160 Specific standards for provisions for flood hazard reduction.

In all areas of special flood hazard where base flood elevation data has been provided as set forth in TMC 15.30.060 or 15.30.130(D), the following provisions are required:

A. Residential Construction.

1. In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained, new construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated one foot or more above the base flood elevation. Mechanical equipment and utilities shall be waterproofed or elevated at least one foot above the base flood elevation.

2. In AO zones, new construction and substantial improvements of residential structures and manufactured homes shall have the lowest floor including the basement and mechanical equipment elevated above the highest adjacent grade to the structure, one foot or more above the depth number specified in feet on the community’s FIRM or at least two feet above the highest adjacent grade to the structure if no depth number is specified.

3. In AO zones, drainage paths are required around structures on slopes to guide floodwaters around and away from proposed structures.

4. New construction and substantial improvement of any residential structure in an unnumbered A zone for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from flooding, but in all cases, the lowest floor shall be at least two feet above the highest adjacent grade.

5. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited or, if used solely for parking, access or storage shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria:

a. 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; and

d. A garage attached to a residential structure, constructed with a garage floor slab below the base flood elevation, must be designed to allow the automatic entry and exit of floodwaters.

B. Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet all of the requirements of either subsection (B)(1) or (B)(2) of this section.

1. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet all of the following requirements:

a. In AE and A1-30 zones or other A zoned areas where the base flood elevation has been determined or can be reasonably obtained, new construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall have the lowest floor, including basement, elevated one foot or more above the base flood elevation, or elevated as required by ASCE 24, whichever is greater. Mechanical equipment and utilities shall be waterproofed or elevated at least one foot above the base flood elevation, or as required by ASCE 24, whichever is greater;

b. In AO zones, new construction or substantial improvements of nonresidential construction shall either:

i. Have the lowest floor including the basement elevated above the highest adjacent grade of the building site, one foot or more above the depth specified on the FIRM or at least two feet if no depth number is specified; or

ii. Together with attendant utility and sanitary facilities, be completely floodproofed to or above that 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 capability 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 subsection (B)(2)(c) of this section;

c. In AO zones, drainage paths are required around structures on slopes to guide floodwaters around and away from proposed structures;

d. If located in an unnumbered A zone for which a BFE is not available and cannot be reasonably obtained, the structure shall be reasonably safe from flooding, but in all cases, the lowest floor shall be at least two feet above the highest adjacent grade; and

e. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited or, if used solely for parking, access or storage, 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:

i. Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding;

ii. The bottom of all openings shall be no higher than one foot above grade;

iii. 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

iv. A garage attached to a structure, constructed with the garage floor slab below the base flood elevation, must be designed to allow for the automatic entry and exit of floodwaters.

v. Alternatively, a registered engineer or architect may design and certify engineered openings.

2. If the requirements of subsection (B)(1) of this section are not met, then new construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet all of the following requirements:

a. Be dry floodproofed so that below one foot or more above the base flood level the structure is watertight with walls substantially impermeable to the passage of water or dry floodproofed to the elevation required by ASCE 24, whichever is greater;

b. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;

c. Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this subsection based on their development and/or review of the structural design, specifications and plans. Such certifications shall be provided to the official as set forth in TMC 15.30.130(E)(2); and

d. Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection (A)(5) of this section.

C. Manufactured Homes. All manufactured homes to be placed or substantially improved on sites shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated 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.

D. Recreational Vehicles. Recreational vehicles placed on sites are required to either:

1. Be on the 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 subsection C of this section and the elevation and anchoring requirements for manufactured homes.

E. Enclosed Areas Below the Lowest Floor. If buildings or manufactured homes are constructed or substantially improved with fully enclosed areas below the lowest floor, the areas shall be used solely for parking of vehicles, building access, or storage.

F. Appurtenant structures, detached garages and small storage sheds in A zones (A, AE, A1, A1-30, AH and AO) shall meet the following requirements:

1. Appurtenant structures used solely for parking of vehicles or limited storage may be constructed such that the floor is below the BFE, provided the structure is designed and constructed in accordance with the following requirements:

a. Use of the appurtenant structure must be limited to parking of vehicles or limited storage;

b. The portions of the appurtenant structure located below the base flood elevation must be built using flood-resistant materials;

c. The appurtenant structure must be adequately anchored to prevent flotation, collapse and lateral movement;

d. Any machinery or equipment servicing the appurtenant structure must be elevated or floodproofed to or above the base flood elevation;

e. The appurtenant structure must comply with floodway encroachment provisions in TMC 15.30.180(A);

f. The appurtenant structure must be designed to allow for the automatic entry and exit of floodwaters in accordance with subsection (A)(5) of this section;

g. The structure shall have low damage potential;

h. If the structure is converted to another use, it must be brought into full compliance with the standards governing such use; and

i. The structure shall not be used for human habitation. (Ord. 2021-03 § 1, 2021; Ord. 2010-8, 2010; Ord. 2007-12 § 5.2, 2007).

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

In areas with base flood elevations (but 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 foot at any point within the community. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 5.3, 2007).

15.30.180 Floodways.

Located within areas of special flood hazard established in TMC 15.30.060 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that can carry debris, and increased erosion potential, the following provisions apply:

A. No Rise Standard. Prohibit encroachments, including fill, new construction, substantial improvements, and other development, unless certification by a registered professional engineer is provided demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practices that the proposed encroachment would not result in an increase in flood levels during the occurrence of the base flood discharge.

B. Residential Construction in Floodways. Construction or reconstruction of residential structures is prohibited within designated floodways, except for:

1. Repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and

2. Repairs, reconstruction or improvements to a structure, the cost of which does not exceed 50 percent of the market value of the structure either:

a. Before the repair or reconstruction is started; or

b. If the structure has been damaged, and is being restored, before the damage occurred. 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 to structures identified as historic places, may be excluded in the 50 percent.

C. Substantially damaged residences in the floodway shall comply with the following:

1. For all substantially damaged residential structures, other than farmhouses, located in a designated floodway, the floodplain administrator may make a written request that the Department of Ecology assess the risk of harm to life and property posed by the specific conditions of the floodway. Based on analysis of depth, velocity, flood-related erosion, channel migration, debris load potential, and flood warning capability, the Department of Ecology may exercise best professional judgment in recommending to the local permitting authority repair, replacement, or relocation of a substantially damaged structure consistent with WAC 173-158-076. The property owner shall be responsible for submitting to the local government and the Department of Ecology any information necessary to complete the assessment. Without a favorable recommendation from the department for the repair or replacement of a substantially damaged residential structure located in the regulatory floodway, no repair or replacement is allowed per WAC 173- 158-070(1).

2. Before the repair, replacement, or reconstruction is started, all requirements of the NFIP, the state requirements adopted pursuant to Chapter 86.16 RCW and all applicable local regulations must be satisfied. In addition, the following conditions must be met:

a. There is no potential safe building location for the replacement residential structure on the same property outside the regulatory floodway;

b. A replacement residential structure is a residential structure built as a substitute for a legally existing residential structure of equivalent use and size;

c. Repairs, reconstruction, or replacement of a residential structure shall not increase the total square footage of floodway encroachment;

d. The elevation of the lowest floor of the substantially damaged or replacement residential structure is a minimum of one foot higher than the base flood elevation;

e. New and replacement water supply systems are designed to eliminate or minimize infiltration of floodwater into the system;

f. New and replacement sanitary sewerage systems are designed and located to eliminate or minimize infiltration of floodwater into the system and discharge from the system into the floodwaters; and

g. All other utilities and connections to public utilities are designed, constructed, and located to eliminate or minimize flood damage.

D. All Other Building Standards That Apply in the Floodway. If subsection A of this section is satisfied or construction is allowed pursuant to subsection B of this section, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of TMC 15.30.155 through 15.30.195. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 5.4, 2007).

15.30.185 General requirements for other development.

All development, including manmade changes to improved or unimproved real estate for which specific provisions are not specified in this chapter or the state building codes with adopted amendments and any city of Toppenish amendments shall:

A. Be located and constructed to minimize flood damage;

B. Meet the encroachment limitations of this chapter, if located in a regulatory floodway;

C. Be anchored to prevent flotation, collapse, or lateral movement resulting from hydrostatic loads, including the effects of buoyancy, during conditions of the design flood;

D. Be constructed of flood damage-resistant materials;

E. Meet the flood opening requirements of TMC 15.30.160(A)(5); and

F. Have mechanical, plumbing, and electrical systems above the design flood elevation or meet the requirements of ASCE 24, except that minimum electric service required to address life safety and electric code requirements is permitted below the design flood elevation, provided it conforms to the provisions of the electrical part of the International Building Code for wet locations. (Ord. 2021-03 § 1, 2021).

15.30.190 Critical facility.

Construction of new critical facilities shall be, to the extent possible, located outside the limits of the special flood hazard area (SFHA) (100-year floodplain). Construction of new critical facilities shall be permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated three feet above BFE or to the height of the 500-year flood, whichever is higher. Access to and from the critical facility should also be protected to the height utilized above. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters. Access routes elevated to or above the level of the base flood elevation shall be provided to all critical facilities to the extent possible. (Ord. 2021-03 § 1, 2021; Ord. 2007-12 § 5.7, 2007).

15.30.195 Livestock sanctuaries.

Elevated areas to create a flood sanctuary for livestock are allowed on farm units where livestock is allowed. Livestock flood sanctuaries shall be sized appropriately for the expected number of livestock and be elevated sufficiently to protect livestock. Proposals for livestock flood sanctuaries shall meet all procedural and substantive requirements of this chapter. (Ord. 2021-03 § 1, 2021).

15.30.200 Severability.

The ordinance codified in this chapter and the various parts thereof are hereby declared to be severable. Should any section of this chapter be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole or any portion thereof other than the section so declared to be unconstitutional or invalid. (Ord. 2021-03 § 1, 2021).