Chapter 16.26
FREQUENTLY FLOODED AREAS

Sections:

16.26.010    Purpose.

16.26.015    Methods of reducing flood losses.

16.26.020    Repealed.

16.26.030    General provisions.

16.26.040    Administration.

16.26.050    Floodplain reasonable use exception.

16.26.060    General standards for flood hazard reduction.

16.26.070    Critical facility.

16.26.080    Repealed.

16.26.010 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 areas of special flood hazard;

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

G. To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions. (Ord. 1570 § 1, 2017; Ord. 1301 § 5, 2009).

16.26.015 Methods of reducing flood losses.

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

A. Restricting or prohibiting uses that are dangerous to health, safety, and property due to water or erosion hazards, or result in damaging increases in erosion or in flood heights or velocities;

B. Requiring that uses vulnerable to floods, including facilities that serve such uses, be protected against flood damage at the time of initial construction;

C. Controlling the alteration of natural floodplains, stream channels, and natural protective barriers which help to accommodate or channel floodwaters;

D. Controlling filling, grading, dredging, and other development that 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. 1301 § 5, 2009).

16.26.020 Definitions.

Repealed by Ord. 1615. (Ord. 1570 § 2, 2017; Ord. 1301 § 5, 2009).

16.26.030 General provisions.

A. Lands to Which This Chapter Applies. This chapter shall apply to all areas of special flood hazards within the jurisdiction of the city of Bonney Lake.

B. Basis for Establishing Special Flood Hazard Areas. The special flood hazard areas identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for Pierce County, Washington and Incorporated Areas” dated March 7, 2017, and any subsequent revisions, with an accompanying Flood Insurance Rate Map (FIRM) dated March 7, 2017, and any subsequent revisions, are adopted by reference and declared to be a part of this chapter. The Flood Insurance Study and the FIRM are on file at the office of the public services department located at 9002 Main St. E., Bonney Lake, WA. The best available information for flood hazard area identification as outlined in BLMC 16.26.040(D) shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under that section.

C. 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. Violations of the provisions of this chapter by failure to comply with any of its requirements shall constitute a misdemeanor, punishable in accordance with Chapter 1.16 BLMC, including violations of conditions and safeguards established in connection with conditions. Nothing shall prevent the city from taking such other 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 easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

E. 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 nor repeal any other powers granted under state statutes.

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 manmade or natural causes. This chapter does not imply that land outside the special flood hazards areas 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, any officer or employee of the city, or the Federal Insurance Administration for any flood damages that result from reliance on this chapter or any administrative decision lawfully made in accordance with this chapter. (Ord. 1570 § 3, 2017; Ord. 1523 § 5, 2015; Ord. 1301 § 5, 2009).

16.26.040 Administration.

A. Development Permit Required. A critical areas permit shall be obtained before construction or development begins within any special flood hazard area established in BLMC 16.26.030(B). The permit shall be for all structures including manufactured homes, and for all development including fill and other activities.

B. Application for Development Permit. Application for a development permit shall be through a critical areas permit and may include, but not be limited to, plans 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, in addition to the requirements of BLMC 16.20.090, critical area reports for frequently flooded areas shall include the following information:

1. Elevation in relation to mean sea level, of the lowest floor of all structures shown on a current elevation certificate, including the basement;

2. Elevation in relation to mean sea level to which any structure has been floodproofed;

3. Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet floodproofing criteria in BLMC 16.26.060(F)(2);

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

5. If the project involves the alteration or relocation of a watercourse or the placement of fill within a floodplain, a model shall be provided to demonstrate that there is not a loss of storage within the watercourse or floodplain;

6. Biological assessment or consultation as required under the Endangered Species Act.

C. The local administrator is appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions.

1. Duties and Responsibilities of the Local Administrator. Duties of the local administrator or designee shall include, but not be limited to:

2. 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, or local governmental agencies from which prior approval is required.

c. 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 BLMC 16.26.060(H)(1) are met.

D. Use of Other Base Flood Data. When base flood elevation data has not been provided in an A Zone in accordance with BLMC 16.26.030(B), Basis for Establishing Special Flood Hazard Areas, the local 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 BLMC 16.26.060(F), Specific Standards, and BLMC 16.26.060(H), Floodways.

E. Information to Be Obtained and Maintained.

1. Where base flood elevation data is provided through the Flood Insurance Study (FIS), Flood Insurance Rate Map (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 the 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.

b. Maintain the floodproofing certifications required in subsection (B)(3) of this section.

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

F. Alteration of Watercourses.

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 Administration.

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

G. Interpretation of FIRM Boundaries. Make interpretations where needed, as to exact location of the boundaries of special flood hazards areas, specifically 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 BLMC 16.26.050. (Ord. 1615 § 12, 2019; Ord. 1570 § 4, 2017; Ord. 1301 § 5, 2009).

16.26.050 Floodplain reasonable use exception.

A. Generally, the only condition under which a deviation from the elevation standard may be issued is for new construction and substantial improvements to be erected on a lot one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level. As the lot size increases the technical justification required for issuing the deviation increases.

B. A reasonable use exception shall not be issued within a designated floodway if any increase in flood levels during the base flood discharge would result.

C. Repealed by Ord. 1570.

D. A reasonable use exception shall only be issued upon:

1. A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief;

2. A showing of good and sufficient cause;

3. A determination that failure to grant the deviation would result in exceptional hardship to the applicant;

4. A determination that the granting of a deviation 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;

5. A favorable biological assessment as required under the Endangered Species Act;

6. Demonstrating 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 BLMC 16.20.030 in the definition of “functionally dependent use.”

E. In determining whether a reasonable use exception should be granted, the hearing examiner shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and the following:

1. The danger that materials may be swept onto other lands to the injury of others;

2. The danger of life and property due to flooding or erosion damage;

3. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;

4. The importance of the services provided by the proposed facility to the community;

5. The necessity to the facility of a waterfront location, where applicable;

6. The availability of alternative locations for the proposed use, which are not subject to flooding or erosion damage;

7. The compatibility of the proposed use with existing and anticipated development;

8. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;

9. The safety of access to the property in time of flood for ordinary and emergency vehicles;

10. The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters expected at the site; and

11. 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.

F. A reasonable use exception established under this section is the same as a variance as interpreted in the National Flood Insurance Program (NFIP). Under the NFIP variances are based on the general zoning law principle in that a variance shall only pertain to a physical piece of property; they are not personal in nature and do not pertain to the structure, its inhabitants, economic or financial circumstances. They primarily address small lots in densely populated residential neighborhoods. As such, deviations from flood elevations should be quite rare.

G. A reasonable use exception may be issued for nonresidential buildings in very limited circumstances to allow a lesser degree of floodproofing than watertight or dry-floodproofing, where it can be determined that such action will have low damage potential, complies with all other exemption criteria except subsection B of this section, and otherwise complies with BLMC 16.26.060(A), (C) and (D), general standards.

H. Any applicant to whom a reasonable use exception is granted shall be given written notice that:

1. The issuance of a deviation to construct a structure below the base flood elevation 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 base flood elevation increases risks to life and property. (Ord. 1615 § 13, 2019; Ord. 1570 § 5, 2017; Ord. 1301 § 5, 2009).

16.26.060 General standards for flood hazard reduction.

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

A. Anchoring.

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

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, 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 so as to prevent water from entering or accumulating within the components during conditions of flooding.

C. Utilities.

1. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems.

2. Water wells shall be located where they are not subject to ponding and are not in a floodway, except as provided in Chapter 86.16 RCW.

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 and Multifamily Proposals.

1. All subdivision proposals shall be consistent with the need to minimize flood damage.

2. All subdivision proposals shall have public utilities and facilities, such as sewer, gas, electrical, and water systems, located and constructed to minimize or eliminate flood damage.

3. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage.

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 developments that contain at least 50 lots or five acres, whichever is less.

5. Density calculations shall not include floodways or special flood hazard areas.

E. Review of Building Permits. Where elevation data is not available either through the Flood Insurance Study (FIS), Flood Insurance Rate Maps (FIRM), or from another authoritative source (BLMC 16.26.040(D)), 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 the highest adjacent grade in these zones may result in higher insurance rates.

F. Specific Standards. In all areas of special flood hazards where base flood elevation data has been provided as set forth in BLMC 16.26.030(B), Basis for Establishing Special Flood Hazard Areas, or BLMC 16.26.040(D), Use of Other Base Flood Data, the following criteria apply:

1. Residential Construction.

a. 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 (BFE).

b. 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 minimum criteria:

i. 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.

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

iii. Openings may be equipped with screens, louvers, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters.

2. Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated one foot or more above the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

a. Be 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.

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 BLMC 16.26.040(E)(2).

d. Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection (F)(1)(b) of this section.

e. Nonresidential buildings that are floodproofed will have flood insurance premiums based on rates that are one foot below the floodproofed level.

3. Below-Grade Crawlspaces. Below-grade crawlspaces are allowed if, in addition to the above requirements, the following requirements are met:

a. The interior grade of a crawlspace below the BFE must not be more than two feet below the lowest adjacent exterior grade (LAG), shown as D in Figure 3 of Bulletin 11-01.

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; this is illustrated and shown as L in Figure 3. The height limitation is the maximum allowable unsupported wall height according to the engineering analyses and building code requirements for flood hazard areas. Also see the section Guidance for Pre-Engineered Crawlspaces on page 7 of Bulletin 11-01.

c. Adequate drainage must be supplied that removes floodwaters from the interior areas of the crawlspace. The enclosed area should be drained within a reasonable time after a flood event. The type of drainage system will vary because of the site gradient and other drainage characteristics, such as soil types. 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 or mechanical means.

d. The velocity of floodwaters at the site should not exceed five feet per second for any crawlspace. For velocities in excess of five feet per second, other foundation types should be used.

e. Ductwork shall either be placed above the BFE or sealed to prevent the entry of floodwaters.

f. Buildings that have below-grade crawlspaces will have higher flood insurance premiums than buildings that have the interior elevation at or above the lowest adjacent exterior grade. For additional information refer to FEMA Technical Bulletin 11.

4. Manufactured Homes. All manufactured homes in the floodplain 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 is securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

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

a. Be on the site for fewer than 180 consecutive days;

b. 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

c. Meet the requirements of subsection (F)(3) of this section and the elevation and anchoring requirements for manufactured homes.

G. AE and A1 – A30 Zones with Base Flood Elevations but No Floodways. In areas with base flood elevations, but a regulatory floodway is not designated, no new construction, substantial improvements, fill, or other development shall be permitted within Zones A1 – A30 and AE, 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 affected floodplain.

H. Floodways. Designated floodways are located within areas of special flood hazard established in BLMC 16.26.030(B). Since the floodway is an extremely hazardous area due to the velocity of floodwaters that can carry debris, and increase erosion potential, the following provisions apply:

1. Encroachments are prohibited. This includes 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 practice that the proposed encroachment would not result in any increase in flood levels during the occurrence of the base flood discharge;

2. Construction or reconstruction of residential structures is prohibited within designated floodways, except for:

a. Repairs, reconstruction, or improvements to a structure that do not increase the ground floor area.

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

i. Before the repair or reconstruction is started; or

ii. If the structure has been damaged, and is being restored, before the damage occurred;

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

d. Structures identified as historic places.

3. If subsection (H)(1) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of BLMC 16.26.060. (Ord. 1570 § 6, 2017; Ord. 1523 § 6, 2015; Ord. 1301 § 5, 2009).

16.26.070 Critical facility.

Construction of new critical facilities shall be, to the extent possible, located outside the limits of areas of special flood hazard. Construction of new critical facilities shall be permissible within areas of special flood hazard if no feasible alternative site is available. Critical facilities constructed within areas of special flood hazard 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. 1570 § 7, 2017; Ord. 1301 § 5, 2009).

16.26.080 Requirements for below-grade crawlspaces.

Repealed by Ord. 1570. (Ord. 1523 § 7, 2015; Ord. 1301 § 5, 2009).