Chapter 17.120 CRITICAL AREAS – FREQUENTLY FLOODED AREAS

Chapter 17.120
CRITICAL AREAS – FREQUENTLY FLOODED AREAS – SPECIFIC STANDARDS

Sections:

17.120.010 Purpose.

17.120.020 General provisions.

17.120.025 Relationship to general standards for critical areas.

17.120.030 Administration.

17.120.035 Critical area reports – Specific requirements for frequently flooded areas.

17.120.040 Provisions for flood hazard reduction.

17.120.050 Specific standards.

17.120.060 Encroachments.

17.120.070 Prohibited uses.

17.120.080 Variance procedure and appeal process.

17.120.090 Conditions for variances.

17.120.010 Purpose.

The purpose of these standards is to:

(1) Protect human life and property;

(2) Minimize the expenditure of public money; and

(3) Maintain the city’s flood insurance eligibility while avoiding regulations which are unnecessarily restrictive or difficult to administer. (Ord. 929 Ch. 10(F)(1), 1995).

17.120.020 General provisions.

(1) Lands to Which These Standards Apply. These standards shall apply to all areas of special flood hazards within the jurisdiction of the city of Stanwood. Special flood hazards may result from high river flow, alteration of river channels, tsunami, high tides combined with high winds, sea level rise associated with global warming, and increased runoff due to increased impervious surface area.

(2) Basis for Establishing the Areas of Special Flood Hazard. The areas of special flood hazard identified by the Federal Emergency Management Agency in a scientific and engineering report entitled “The Flood Insurance Study for Snohomish County, Washington and Incorporated Areas,” dated November 8, 1999, and any revisions thereto, with accompanying Flood Insurance Rate Map (FIRM), and any revisions thereto, is adopted by reference and declared to be a part of this code. The flood insurance study is on file at the City Hall, 10220 270th Street N.W., Stanwood, WA 98292.

(3) Penalties for Noncompliance. No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of these standards and other applicable regulations. Violation of the provisions of these standards by failure to comply with any of their requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute a misdemeanor. Nothing herein contained shall prevent the city of Stanwood from taking such other lawful action as is necessary to prevent or remedy any violation.

(4) Abrogation and Greater Restrictions. These standards are not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where these standards and any other code, easement, covenant, or deed restriction conflict or overlay, whichever imposes the more stringent restrictions shall prevail.

(5) Interpretation. In the interpretation and application of these standards, all provisions shall be:

(a) Considered as minimum requirements;

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

(6) Warning and Disclaimer of Liability. The degree of flood protection required by these standards 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 humanmade or natural causes. These standards do not imply that land outside the areas of special flood hazards, or use permitted within such areas, will be free from flooding or flood damages. These standards shall not create liability on the part of the city of Stanwood, any officer or employee thereof, or the Federal Emergency Management Agency, for any flood damages that result from reliance on them or any administrative decision lawfully made hereunder. (Ord. 1164 § 4, 2004; Ord. 1089 §§ 1, 2, 2000; Ord. 929 Ch. 10(F)(2), 1995).

17.120.025 Relationship to general standards for critical areas.

This chapter contains standards specific to frequently flooded areas, and should be considered in conjunction with the standards in Chapter 17.114 SMC. Please refer to that chapter for general standards and administration. In the event of a conflict between this chapter and Chapter 17.114 SMC, this chapter shall prevail. (Ord. 1164 § 4, 2004).

17.120.030 Administration.

(1) Designation of the Administrator. The planning director, or his designee, is hereby appointed to administer and implement these standards by granting or denying development permit applications in accordance with their provisions. The duties of the planning director shall include, but not be limited to:

(a) Permit Review.

(i) Review all development permits to determine that the permit requirements of these standards have been satisfied;

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

(2) Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with SMC 17.120.020(2), Basis for Establishing the Areas of Special Flood Hazard, the planning director shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state, or other source.

(3) Information to Be Obtained and Maintained.

(a) Where base flood elevation data is provided through the flood insurance study or otherwise required, these data shall be obtained and a record made of 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.

(b) For all new substantially improved floodproofed structures:

(i) Verify and record the actual elevation (in relation to mean sea level) to which the structure was floodproofed.

(ii) Maintain the floodproofing certifications required in SMC 17.120.030(7)(c).

(4) Alteration of Watercourses.

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

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

(5) Interpretation of FIRM Boundaries. Make interpretations, where needed, as to exact location of the boundaries of the areas of special flood hazards. (For example, where there appears to be a conflict between a mapped boundary and actual field conditions.) The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation.

(6) Development Permit Required. A development permit shall be obtained before construction or development begins within any area of special flood hazard. The permit shall be for all structures, including manufactured homes (as set forth in the definitions of this code), and for all development, including fill and other activities.

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

(a) Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;

(b) Elevation in relation to mean sea level to which any structure has been floodproofed;

(c) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in SMC 17.120.050(2); and

(d) Description of the extent to which a watercourse will be altered or relocated as a result of the proposed development. (Ord. 1089 §§ 3 – 6, 2000; Ord. 929 Ch. 10(F)(3), 1995).

17.120.035 Critical area reports – Specific requirements for frequently flooded areas.

In addition to the general requirements of SMC 17.114.160, critical area reports for frequently flooded areas must meet the requirements of this section.

(1) Prepared by a Qualified Professional. A critical areas report for a frequently flooded area shall be prepared by a qualified professional who is a hydrologist or engineer and who is licensed in the state of Washington with experience in preparing flood hazard assessments.

(2) Area addressed in critical area report:

(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

(3) Flood Hazard Assessment Required. A critical area 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- 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. (Ord. 1164 § 4, 2004).

17.120.040 Provisions for flood hazard reduction.

In all areas of special flood hazard, the following standards are required to be met:

(1) Anchoring.

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

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

(2) Construction Materials and Methods.

(a) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

(b) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

(c) 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.

(d) All structures, utilities and other improvements shall be located on the buildable portion of the site out of the floodplain unless there is no buildable site area out of the floodplain. For sites with no buildable area out of the floodplain, structures shall be placed on the highest land on the site, oriented parallel to flow rather than perpendicular, and sited as far from the watercourse and other critical areas as possible. If the city detects any evidence of active hyporheic exchange on a site, the development shall be located to minimize disruption of such exchange.

(e) 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 has delineated such zones as of the time of the application.

(3) Utilities.

(a) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.

(b) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems in flood waters.

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

(4) Subdivision Proposals.

(a) All subdivision proposals shall be consistent with the need to minimize flood damage.

(b) 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.

(d) 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 which contain at least 50 lots or five acres (whichever is less).

(5) Review of Building Permits. Where elevation data is not available either through the flood insurance study, or from another authoritative source, applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness includes use of historic data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet above grade in these areas may result in higher insurance rates. (Ord. 1164 § 4, 2004; Ord. 1089 § 7, 2000; Ord. 929 Ch. 10(F)(4)(a), 1995).

17.120.050 Specific standards.

In all areas of special flood hazards where base flood elevation data have been provided as set forth in SMC 17.120.020(2), Basis for Establishing the Areas of Special Flood Hazard, or SMC 17.120.030(2), Use of Other Base Flood Data, the following provisions are required:

(1) Residential Construction.

(a) New construction and substantial improvement of any residential structure shall have the lowest floor elevated to the base flood elevation plus one foot.

(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 flood waters. 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; and

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

(2) Nonresidential Construction.

(a) New construction and substantial improvement to any commercial, industrial, or other nonresidential structure shall either have the lowest floor elevated to the level of the base flood elevation plus one foot, or, together with attendant utility and sanitary facilities, shall:

(i) Be floodproofed so that below one foot above the base flood level, the structure is watertight, with walls substantially impermeable to the passage of water;

(ii) Have structural components 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 the provisions of this subsection based on their development and/or review of the structural design, specifications, and plans. Such certification shall be provided to the planning director as set forth in SMC 17.120.030(3)(b);

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

(v) Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (e.g., a building floodproofed to one foot above the base flood level will be rated as at the base flood level).

(3) Manufactured Homes.

(a) All manufactured homes to be placed or substantially improved on the following 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 the foundation system to resist flotation, collapse, and lateral movement:

(i) Outside of a manufactured home park or subdivision;

(ii) In a new manufactured home park or subdivision;

(iii) In an expansion to an existing manufactured home park or subdivision; or

(iv) In an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as the result of a flood.

(b) Manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision that are not subject to the above manufactured home provisions must be elevated so that either:

(i) The lowest floor of the manufactured home is elevated one foot or more above the base flood elevation; or

(ii) The manufactured home chassis is supported by reinforced piers or other foundation elements, of at least equivalent strength that are no less than 36 inches in height above grade, and is securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

(4) Recreational Vehicles. Recreational vehicles to be placed on sites within zones A1 – A30 and AE on the community’s FIRM are required to either:

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

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

(c) Must obtain a development permit and meet the requirements, including elevation and anchoring, for manufactured homes.

(5) Areas of Shallow Flooding. Uses in areas of shallow flooding shall adhere to the following standards, in addition to the other requirements of this chapter:

(a) 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.

(b) Nonresidential Structures. New construction and substantial improvements of nonresidential structures within AO zones shall either:

(i) 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

(ii) Together with attendant utility and sanitary facilities, be completely flood-proofed 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 that record the actual (as-built) elevation to which the structure was floodproofed.

(c) Drainage Paths. All development shall include adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.

(d) Recreational Vehicles. Recreational vehicles placed on sites within AO zones on the flood insurance map(s) shall meet the requirements of this chapter. (Ord. 1250 § 7, 2009; Ord. 1164 § 4, 2004; Ord. 1089 § 8, 2000; Ord. 929 Ch. 10(F)(4)(b), 1995).

17.120.060 Encroachments.

The cumulative effect of any proposed development, when combined with all other existing and anticipated development, shall not increase the water surface elevation of the base flood more than one foot at any point. (Ord. 929 Ch. 10(F)(4)(c), 1995).

17.120.070 Prohibited uses.

Uses and activities prohibited from frequently flooded areas:

(1) Critical facilities are prohibited from frequently flooded areas to prevent damage to such facilities, to avoid costs that will be incurred by the public, and to maintain functionality of such facilities during flood events. If such a prohibition is unreasonable, an allowance for critical facilities in frequently flooded areas can be made with the following specific conditions:

(a) Construction of new critical facilities shall be permissible within frequently flooded areas if no feasible alternative site is available.

(b) Critical facilities constructed within frequently flooded areas shall have the lowest floor elevated three feet or more above the level of the base flood elevation (100-year flood).

(c) Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into flood waters.

(d) Access routes elevated to or above the level of the base flood elevation shall be provided to all critical facilities to the extent possible.

(2) Wells used for potable water are prohibited from the floodway.

(3) On-site sewage disposal systems are prohibited from the floodway, the channel migration zone, and the 10-year floodplain elevation. (Ord. 1164 § 4, 2004; Ord. 929 Ch. 10(F)(4)(d), 1995).

17.120.080 Variance procedure and appeal process.

(1) Variances from these regulations and appeals shall be heard as provided by the land use process table, SMC 17.80.130.

(2) In reviewing such applications for variances, the city shall consider all technical evaluations, all relevant factors, criteria specified in other sections of these standards criteria in SMC 17.114.190, and:

(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;

(d) The importance of the services provided by the proposed facility to the community;

(e) The necessity that the facility have a waterfront location, where applicable;

(f) The availability of alternative locations for the proposed use that are not subject to the 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 city’s Comprehensive Plan and floodplain management program for that area;

(i) The safety of access to the property in times of flood for ordinary and emergency vehicles;

(j) The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, 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 systems, and streets and bridges. (Ord. 1164 § 4, 2005; Ord. 1084 § 3, 2000; Ord. 929 Ch. 10(F)(5)(a), 1995).

17.120.090 Conditions for variances.

(1) Variances shall only be issued upon a determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, nuisances, fraud on or victimization of the public, or conflict with existing laws or ordinances. Unavoidable impacts to floodplain functions and values shall be mitigated in accordance with SMC 17.114.180(4), Mitigation Sequencing.

(2) Variances may be issued for the reconstruction, rehabilitation, or restoration of structures listed on the National Register of Historic Places, the State Inventory of Historic Places, or for structures determined to be historically significant by the Stanwood Area Historical Society without regard to the procedures set forth in this chapter.

(3) Variances shall not be issued within a designated floodway if any increase in flood levels during the base flood discharge would result.

(4) Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

(5) Variances shall be issued upon:

(a) A showing of good and sufficient cause;

(b) A determination that failure to grant the variance would result in exceptional hardship to the applicant; and

(c) 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 or victimization of the public, or conflict with the existing local laws and codes.

(6) Variances, as interpreted in the National Flood Insurance Program, are based on the general zoning law principle that they pertain to a physical piece of property; they are not personal in nature and do not pertain to the structure or its inhabitants’ economical or financial circumstances. They primarily address small lots in densely populated residential neighborhoods. As such, variances from the flood elevation should be quite rare.

(7) Variances 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 variance criteria, except subsection (1) of this section, and otherwise complies with SMC 17.120.040(1) through (3).

(8) Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased rise resulting from the reduced lowest floor elevation. (Ord. 1164 § 4, 2004; Ord. 1110 § 3, 2002; Ord. 1089 §§ 9, 10, 2000; Ord. 929 Ch. 10(F)(5)(b), 1995).