Chapter 12.11
FREQUENTLY FLOODED AREAS
Sections:
12.11.010 Designation of frequently flooded areas.
12.11.020 Critical areas report – Additional requirements.
12.11.030 Warning and disclaimer of liability.
12.11.040 Performance standards – General requirements.
12.11.050 Performance standards – Specific uses.
12.11.060 Performance standards – Areas of shallow flooding.
12.11.070 Uses and activities prohibited from frequently flooded areas.
12.11.005 Definitions.
In addition to the definitions in Chapter 12.08 BMC, the following definitions will be used for this chapter. If any term is defined differently in the municipal code, the following terms shall take precedence for floodplains and floodways:
“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.
“Elevation certificate” means the official form (FEMA Form 086-0-33) used to track development and provide elevation information necessary to ensure compliance with community floodplain management ordinances, and determine the proper insurance premium rate with Section B completed by community officials.
“Increased cost of compliance” means a flood insurance claim payment up to $30,000 directly to a property owner for the cost to comply with floodplain management regulations after a direct physical loss caused by a flood. Eligibility for an ICC claim can be through a single instance of “substantial damage” or as a result of a “cumulative substantial damage.” (More information can be found in FEMA ICC Manual 301.)
“Mobile home park or subdivision” means one of the following:
(a) “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 floodplain management regulations adopted by a community.
(b) “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 manufacturing 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).
(c) “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 floodplain management regulations adopted by a community.
“New construction” means structures for which the “start of construction” commenced on or after the effective date of an initial FIRM 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 a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures.
“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 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 part of a building, whether or not that alteration affects the external dimensions of the building.
“Structure” means, for floodplain 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.
“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.
“Substantial improvement” 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:
(a) Before the improvement or repair is started; or
(b) If the structure has been damaged and is being restored, before the damage occurred. For the purposes 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.
(i) This term “substantial improvement” can exclude:
(A) Any project for improvement of a structure to correct pre-cited existing 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
(B) Any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.
“Violation” for this chapter (floods) means the failure of a structure or other development to be fully compliant with the community’s floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in § 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or (e)(5) is presumed to be in violation until such time as that documentation is provided. (Ord. 10-17 § 1 (Att. A), 2017).
12.11.010 Designation of frequently flooded areas.
(1) Frequently Flooded Areas. Frequently flooded areas shall include:
(a) The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for Pierce County and Incorporated Areas” dated March 7, 2017, and any revisions thereto, with an accompanying flood insurance rate map (FIRM), and any revisions thereto, are hereby adopted by reference and declared to be a part of this chapter. The flood insurance study and the FIRM are on file at the building and planning office. The best available information for flood hazard area identification as outlined in this chapter shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under this chapter.
(b) Areas Identified by the Director. Those areas of special flood hazard identified by the planning director based on review of base flood elevation and floodway data available from federal, state, Pierce County or other valid sources when base flood elevation data has not been provided from the Federal Insurance Administration (A and V zones of the flood insurance map(s)).
(2) Use of Additional Information. The planning director may use additional flood information that is more restrictive or detailed than that provided in the flood insurance study conducted by the Federal Emergency Management Agency (FEMA) to designate frequently flooded areas, including data on channel migration, historical data, high water marks, photographs of past flooding, location of restrictive floodways, maps showing future build-out conditions, maps that show riparian habitat areas, or similar information.
(3) Flood Elevation Data. When base flood elevation data is not available (A and V zones), the planning director 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 this chapter.
(4) Designation Made by Director. The flood insurance maps are to be used as a guide for the city of Buckley, project applicants and/or property owners, and the public, and should be considered a minimum designation of frequently flooded areas. As flood insurance maps may be continuously updated as areas are reexamined or new areas are identified, newer and more restrictive information for flood hazard area identification shall be the basis for regulation.
(5) Maintenance of Records. The planning director shall obtain and record the 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. The planning director shall also maintain for public inspection all records of floodplain hazards, certificates of floodproofing, and flood elevation data. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).
12.11.020 Critical areas report – Additional requirements.
In addition to the general critical areas report requirements of BMC 12.08.210, critical areas reports for frequently flooded areas must meet the requirements of this section. Critical areas reports for two or more types of critical areas must meet the report requirements for each relevant type of critical area.
(1) Prepared by a Qualified Professional. A frequently flooded areas report shall be prepared by a qualified professional who is a hydrologist, or engineer, who is licensed in the state of Washington, with experience in preparing flood hazard assessments.
(2) Area Addressed in Critical Areas Report. The following areas shall be addressed in a critical areas report for frequently flooded areas:
(a) The site area of the proposed activity;
(b) All areas of a special flood hazard area, as indicated on the flood insurance map(s) within 200 feet of the project area; and
(c) All other flood areas indicated on the flood insurance map(s) within 200 feet of the project area.
(3) Flood Hazard Assessment Required. A critical areas report for a proposed activity within a frequently flooded area shall contain a flood hazard assessment including the following site- and proposal-related information at a minimum:
(a) Site and Construction Plans. A copy of the site and construction plans for the development proposal showing:
(i) Floodplain (100-year flood elevation), 10-year and 50-year flood elevations, floodway, other critical areas, buffers, and shoreline areas;
(ii) Proposed development, including the location of existing and proposed structures, fill, storage of materials, and drainage facilities, with dimensions indicating distances to the floodplain;
(iii) Clearing limits; and
(iv) Elevation of the lowest floor (including basement) of all structures, and the level to which any nonresidential structure has been floodproofed;
(b) Watercourse Alteration. When watercourse alteration is proposed, the critical areas report shall include:
(i) Extent of Watercourse Alteration. A description of and plan showing the extent to which a watercourse will be altered or relocated as a result of the proposal;
(ii) Maintenance Program Required for Watercourse Alterations. A maintenance program that provides maintenance practices for the altered or relocated portion of the watercourse to ensure that the flood carrying capacity is not diminished; and
(iii) Compliance Documentation. Information describing and documenting how the proposed water course alteration complies with the requirements of Chapter 12.13 BMC, Fish and Wildlife Habitat Conservation Areas, Chapter 19.42 BMC, Shoreline Management, and other applicable state or federal permit requirements.
(4) Information Regarding Other Critical Areas. Potential impacts to wetlands, fish and wildlife habitat, and other critical areas shall be addressed in accordance with the applicable sections of this title. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).
12.11.030 Warning and disclaimer of liability.
(1) 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 frequently flooded 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 of Buckley, 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.
(2) This title shall not in any way impair/remove the necessity of compliance with any other applicable laws, ordinances, regulations, etc. Where this title imposes a greater restriction, the provisions of this title shall control. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).
12.11.040 Performance standards – General requirements.
The following standards shall be adhered to in all frequently flooded areas, except as otherwise provide for in this chapter:
(1) Development Permit Required. A development permit shall be obtained before land is altered or a new use is commenced within a frequently flooded area. For application of this chapter, development shall include any manmade alteration to land, including but not limited to buildings, structures, mining, dredging, filling, grading, paving, excavation, drilling operations, or storage of equipment or materials within the area of special flood hazard.
(2) All Necessary Permits Shall Be Obtained. The planning director shall verify that all necessary permits have been obtained from those governmental agencies from which prior approval is required by federal, state, or local law, including Section 404 of the Federal Water Pollution Control Act Amendment of 1972 and the Endangered Species Act of 1973.
(3) Before Regulatory Floodway. In areas where the base flood elevation is provided, but where a regulatory floodway has not been designated, new construction, substantial improvements, or other development, including fill, shall not be permitted within zones A1 – 30 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 community.
(4) Areas without Base Flood Elevation Data. Where base flood elevation data is not available (A and V zones), and there is insufficient data available from federal, state, or other sources, the planning director shall determine the base flood elevation using FEMA-approved engineering methods, and historical data, high water marks, photographs of past flooding, and other available information. If there is insufficient data available for the planning director to make a determination of the base flood elevation, and standards requiring a base flood elevation cannot be implemented, the planning director shall require measures that assure the proposed structures will be reasonably safe from flooding. At a minimum, the base flood elevation shall be set at least two feet above the highest adjacent grade.
(5) Construction Materials and Methods.
(a) Methods That Minimize Flood Damage. All new construction and substantial improvements shall be constructed using flood-resistant materials and utility equipment, and with methods and practices that minimize flood damage.
(b) Structures shall be located outside the floodplain. All structures, utilities and other improvements located within the floodplain are required to go through the variance process for review and approval.
(c) Utilities Shall Be Protected. 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.
(6) Elevation Certificate Required Following Construction. Following construction of a structure within the floodplain where the base flood elevation is provided, the applicant shall obtain an elevation certificate that records the elevation of the lowest floor. The elevation certificate shall be completed on a form provided by FEMA by a surveyor or engineer licensed in the state of Washington and shall be submitted to the city of Buckley and Pierce County for recording.
(7) Anchoring.
(a) Anchoring Required. All new construction and substantial improvements within the floodplain shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
(b) Manufactured Homes Shall Be Anchored. All manufactured homes placed within the floodplain must 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.
(8) Fill and Grading. Fill and grading within the floodplain shall only occur upon a determination from a qualified professional that the fill or grading will not block side channels, inhibit channel migration, increase flood hazards to others, or be placed within a channel migration zone, whether or not the city of Buckley has delineated such zones as of the time of the application. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).
12.11.050 Performance standards – Specific uses.
Specific uses shall adhere to the following relevant standards, in addition to the general standards of BMC 12.11.040, Performance standards – General requirements.
(1) Residential Construction.
(a) Must Be above Base Flood Elevation. 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.
(b) Areas below the Lowest Floor. Fully enclosed areas below the lowest floor that are subject to flooding shall only be allowed when 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; and
(ii) The bottom of all openings shall be no higher than one foot above grade; and
(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) Manufactured Homes Must Be Elevated. All manufactured homes to be placed or substantially improved 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.
(3) Recreational Vehicles. Recreational vehicles 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 its wheels or jacking system, be attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or
(c) Must obtain a development permit and meet the requirements, including elevation and anchoring, for manufactured homes.
(4) Nonresidential Construction.
(a) Must Be above Base Flood Elevation. 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:
(i) 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;
(ii) Have structural components that shall be capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
(iii) 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. Following construction of the structure, certifications shall be submitted to the city of Buckley and Pierce County that record the actual (as-built) elevation to which the structure was floodproofed;
(iv) Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (for example, a building floodproofed to the base flood level will be rated as one foot below).
(b) Areas below the Lowest Floor. Fully enclosed areas below the lowest floor that are not floodproofed 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; and
(ii) The bottom of all openings shall be no higher than one foot above grade; and
(iii) Openings may be equipped with screens, louvers, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters.
(5) Utilities.
(a) Shall Be Designed to Minimize Infiltration of Floodwaters. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems.
(b) Sanitary Sewage Systems. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters.
(c) On-Site Waste Disposal Systems. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. New on-site sewage disposal systems are prohibited pursuant to BMC 12.11.070(3), Uses and activities prohibited from frequently flooded areas.
(6) Subdivision Proposals.
(a) All subdivisions and short subdivisions shall:
(i) Minimize Flood Damage. Subdivisions and short subdivisions shall be designed to minimize or eliminate flood damage; and public utilities and facilities that are installed as part of such subdivisions, such as sewer, gas, electrical, and water systems, shall be located and constructed to minimize flood damage; subdivisions should be designed using natural features of the landscape, and should not incorporate “flood protection” changes;
(ii) Have Adequate Drainage. Subdivisions and short subdivisions shall have adequate natural surface water drainage in accordance with Chapter 14.30 BMC to reduce exposure to flood hazards; and
(iii) Show Flood Areas on Plat Maps. Subdivisions and short subdivisions shall show the 100-year floodplain, floodway, and channel migration zone on the preliminary and final plat, and short plat maps;
(b) Lots shall have adequate space outside flood areas. All lots created through subdivision or short subdivision shall have adequate building space outside the 100-year floodplain, the floodway, and the channel migration zone. Adequate building space means that each newly created lot shall maintain a minimum buildable lot area outside of the flood areas which totals 75 percent of the minimum lot size area for the zoning district where located; and
(c) Detailed base flood elevation data shall be generated for subdivisions of at least 50 lots or five acres. Where detailed 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 which contain at least 50 lots or five acres, whichever is less.
(7) Alteration of Watercourses.
(a) Shall Be in Accordance with Habitat Regulations. Watercourse alterations shall only be allowed in accordance with Chapter 12.13 BMC, Fish and Wildlife Habitat Conservation Areas, and Chapter 19.42 BMC, Shoreline Management.
(b) Shall Not Result in Blockage. Watercourse alteration projects shall not result in blockage of side channels.
(c) Notification Required. The city of Buckley shall notify adjacent communities and the State Department of Ecology at least 30 days prior to permit issuance and submit evidence of such notification to the Federal Insurance Administration of the proposed watercourse alteration.
(d) Maintenance of Alterations. The applicant shall indefinitely maintain the altered or relocated portion of the watercourse to ensure that the flood carrying capacity is not diminished. Maintenance shall be bonded for a period of at least five years, and be in accordance with an approved maintenance program. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).
12.11.060 Performance standards – Areas of shallow flooding.
Uses in areas of shallow flooding shall adhere to the following standards, in addition to the general standards of BMC 12.11.040, Performance standards – General requirements, and relevant specific standards of BMC 12.11.050, Performance standards – Specific uses.
(1) Residential Structures. 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, one foot or more above the depth number specified in feet on the flood insurance map or at least two feet if no depth number is specified.
(2) Nonresidential Structures. 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, one foot or more above the depth number specified on the flood insurance map or 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 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 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. Following construction of the structure, certifications shall be submitted to the city of Buckley and Pierce County that record the actual (as-built) elevation to which the structure was floodproofed.
(3) Drainage Paths. All development shall include adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.
(4) Recreational Vehicles. Recreational vehicles placed on sites within AO zones on the flood insurance map(s) shall meet the requirements of this chapter. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).
12.11.070 Uses and activities prohibited from frequently flooded areas.
(1) Critical Facilities. Critical facilities are prohibited from frequently flooded areas.
(2) Wells Used for Potable Water. Water wells used for potable water are prohibited from the floodway.
(3) On-Site Sewage Disposal Systems. On-site sewage disposal systems are prohibited from the floodway, the channel migration zone, and the 10-year floodplain elevation.
(4) Construction in Floodways.
(a) New Construction Requires Certification by an Engineer. Encroachments, including new construction, substantial improvements, fill, and other development, are prohibited within designated floodways unless certified by a registered professional engineer. Such certification shall demonstrate through hydrologic and hydraulic analyses, performed in accordance with standard engineering practice, that the proposed encroachment will not result in any increase in flood levels during the occurrence of the base flood discharge.
Small projects that are solely to protect or create fish habitat and designed by a qualified professional may be allowed without certification if the planning director determines that the project will not obstruct flood flows.
(b) Residential Construction and Reconstruction Prohibited. Construction and reconstruction of residential structures is prohibited within designated floodways, except for:
(i) Repairs, reconstruction, or improvements to a structure that do not increase the ground floor area; and
(ii) Repairs, reconstruction or improvements to a structure for which the cost 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;
Improvement to a structure to correct existing violations of state or local health, sanitary, or safety code specifications that have been identified by the local code enforcement official and that are the minimum necessary to assure safe living conditions or to structures identified as historic places shall not be included in the 50 percent. (Ord. 10-17 § 1 (Att. A), 2017; Ord. 21-05 § 2, 2005).