Chapter 21.30
FLOODPLAIN REGULATIONS
Sections:
21.30.010 Purpose and applicability.
21.30.020 Basis for establishing areas of special flood hazard.
21.30.030 Compliance and enforcement.
21.30.040 Abrogation and greater restrictions.
21.30.060 Warning and disclaimer of liability.
21.30.090 Provisions for flood hazard reduction.
21.30.100 Additional requirements.
21.30.110 Critical facilities.
21.30.010 Purpose and applicability.
The provisions of this chapter shall apply to all areas of special flood hazards within the jurisdiction of Spokane Valley, Washington, and shall be administered in conformance with the National Flood Insurance Act, as amended (codified in 44 CFR 60) and “A Summary of NFIP Policy for Local Officials,” FEMA Region 10 Mitigation Division, July 2001. (Ord. 07-015 § 4, 2007).
21.30.020 Basis for establishing areas of special flood hazard.
The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for Spokane County, Washington, and Incorporated Areas,” dated July 6, 2010, 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 office of the Spokane Valley floodplain administrator. (Ord. 10-010 § 2, 2010; Ord. 07-015 § 4, 2007).
21.30.030 Compliance and enforcement.
No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter. Enforcement procedures for violations of this chapter shall be in conformance with Chapter 17.100 SVMC. (Ord. 07-015 § 4, 2007).
21.30.040 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. 07-015 § 4, 2007).
21.30.050 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. 07-015 § 4, 2007).
21.30.060 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 Spokane Valley, 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. 07-015 § 4, 2007).
21.30.070 Administration.
A. Development Permit Required. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in this chapter. The permit shall be for all structures including manufactured homes, as defined in Appendix A, and for all development including fill and other activities, also defined in Appendix A.
B. Application for Development Permit. Application for a development permit shall be made on forms furnished by the City 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:
1. Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures recorded on a current elevation certificate (FF 81-31) with Section B completed by the local official;
2. Elevation in relation to mean sea level to which any structure has been flood-proofed;
3. Certification by a registered professional land surveyor, engineer or architect that the flood-proofing methods for any nonresidential structure meet the flood-proofing criteria in SVMC 21.30.090(C)(2); and
4. Description of the extent to which a watercourse will be altered or relocated as a result of proposed development.
C. Designation of the Local Administrator. The city manager or designee is hereby designated as floodplain administrator and appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions.
D. Duties and responsibilities of the local administrator shall include, but not be limited to:
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 SVMC 21.30.090(C)(7) are met.
4. When base flood elevation data has not been provided (A and V Zones) in accordance with SVMC 21.30.020, Basis for establishing areas of special flood hazard, the floodplain 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 SVMC 21.30.090(C), Specific Standards, and SVMC 21.30.090(C)(7), Floodways.
5. Where base flood elevation data is provided through the Flood Insurance Study, FIRM, or required as in subsection (D)(4) of this section, the actual 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 shall be recorded on a current elevation certificate (FF 81-31) with Section B completed by the local administrator.
6. For all new or substantially improved flood-proofed structures where base flood elevation data is provided through the Flood Insurance Study, FIRM, or as required in subsection (D)(4) of this section, the local administrator shall:
a. Obtain and record the elevation (in relation to mean sea level) to which the structure was flood-proofed; and
b. Maintain the flood-proofing certifications required in subsection (B)(3) of this section; and
c. Maintain for public inspection all records pertaining to the provisions of this chapter.
7. The local administrator shall:
a. 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.
b. Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood carrying capacity is not diminished.
8. The local administrator shall 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 interpretation of the floodplain administrator in relation to the boundary shall be given a reasonable opportunity to appeal pursuant to the procedures outlined in Chapter 17.90 SVMC, Appeals.
9. The local administrator is expressly authorized to require compliance with all federal and state permit requirements, and may require Letters of Map Amendment (LOMA) and Conditional Letters of Map Revision (CLOMR), particularly where a proposal identifies a floodplain location that is different from that set forth on the official FIRM. (Ord. 17-004 § 3, 2017; Ord. 07-015 § 4, 2007).
21.30.080 Variances.
A. Decision on Variances.
1. The duly appointed hearing examiner shall hear and decide requests for variances from the requirements of this section following notice of not less than 15 days and public hearing. The contents of the appeal shall be as set forth in Chapter 17.90 SVMC. Appeal procedures shall be as set forth in Chapter 17.90 SVMC. The decision or determination of the hearing examiner shall be final unless appealed pursuant to Chapter 36.70C RCW.
2. In passing upon such applications, the hearing examiner shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, 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;
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 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, and water systems, and streets and bridges.
3. Upon consideration of the factors and the purposes of this chapter, the hearing examiner may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter. The City shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request.
B. Conditions for Variances.
1. Generally, the only condition under which a variance from the elevation standard may be issued is 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 level, providing subsections (A)(2)(a) through (k) of this section have been fully considered. As the lot size increases, the technical justification required for issuing the variance increases.
2. Variances may be issued for the reconstruction, rehabilitation, or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places, without regard to the procedures set forth in this section.
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 only be issued upon:
a. A showing of good and sufficient cause, pursuant to subsection (A)(2) of this section;
b. A determination that failure to grant the variance would result in exceptional hardship to the applicant;
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 on or victimization of the public, or conflict with existing local laws or ordinances.
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, its inhabitants, or economic or financial circumstances.
7. Variances may be issued for nonresidential buildings in very limited circumstances to allow a lesser degree of flood-proofing than watertight or dry flood-proofing, where it can be determined that such action will have low damage potential, complies with all other variance criteria except subsection (B)(1) of this section, and otherwise complies with SVMC 21.30.090(A)(1), (2) and (3) of the general standards.
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 risk resulting from the reduced lowest floor elevation.
9. Any appeal of a decision or determination of the local administrator is a decision on a Type II application. An appeal of the decision shall be made pursuant to Chapter 17.90 SVMC. (Ord. 07-015 § 4, 2007).
21.30.090 Provisions for flood hazard reduction.
A. General Standards. In all areas of special flood hazards, the following standards are required:
1. Anchoring.
a. All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
b. Where permitted pursuant to subsection (C)(3) of this section, 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 (reference FEMA’s “Manufactured Home Installation in Flood Hazard Areas” guidebook for additional techniques).
2. AH Zone Drainage. Adequate drainage paths are required around structures on slopes to guide flood waters around and away from proposed structures.
3. 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.
4. Utilities.
a. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the systems;
b. The proposed water well shall be located on high ground that is not in the floodway (WAC 173-160-171);
c. 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; and
d. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
5. Subdivision and Other Proposed Developments.
a. All development 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;
c. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and
d. Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated by a civil engineer licensed in the state of Washington for all short subdivision and subdivision proposals and binding site plans;
e. Pursuant to RCW 58.17.120, no plat shall be approved for any land situated within the 100-year floodplain as provided in Chapter 86.16 RCW without the prior written approval of the Department of Ecology of the state of Washington.
B. Review of Building Permits. Where elevation data is not available either through the Flood Insurance Study, FIRM, 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 is the floodplain administrator’s judgment and includes, but is not limited to, use of historical data, high-water marks, photographs of past flooding, etc., where available. The floodplain administrator may require the applicant to locate the lowest floor at least two feet above the highest adjacent natural ground surface. Failure to elevate at least two feet above the highest adjacent natural ground surface in these zones may result in higher insurance rates.
C. Specific Standards. In all areas of special flood hazards where base flood elevation data has been provided (Zones A1 – 30, AH, and AE) as set forth in SVMC 21.30.020, Basis for establishing areas of special flood hazard, or SVMC 21.30.070(D)(4) relating to 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, including basement, elevated one foot or more above the base flood elevation.
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 professional engineer or architect licensed in the state of Washington 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 flood waters.
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 flood-proofed 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 professional engineer or architect licensed in the state of Washington 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;
d. Nonresidential structures that are elevated, not flood-proofed, must meet the same standards for space below the lowest floor;
e. Applicants flood-proofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the flood-proofed level (e.g., a building flood-proofed to the base flood level will be rated as one foot below).
3. Manufactured Homes. All manufactured homes in the floodplain 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 shall be securely anchored to a permanent foundation system to resist flotation, collapse and lateral movement; provided, however, that manufactured homes to be placed on substantially improved sites in an existing manufactured home park or subdivision which has not experienced substantial damage as a result of flooding shall be elevated so that either:
a. The bottom of the crawlspace of the manufactured home is elevated one foot or more above the base flood elevation; or
b. 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 be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
4. Recreational Vehicles. Recreational vehicles placed on sites are required to either:
a. Be on the site for fewer than 180 consecutive days; or
b. Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions.
5. AE and A1 – 30 Zones with Base Flood Elevations but No Floodways.
a. In areas where 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.
b. In the unnumbered A zones, the development may not increase the water surface elevation of the base flood by more than one foot at any point.
c. In the A zones where base flood elevations have been provided, but floodways have not been established, the development may not increase the surface water elevation of the base flood by more than one-tenth of a foot at any point.
d. All adjacent or other property owners impacted by the development within the floodplain must give their written, notarized approval for any increased base flood elevations upon their property.
6. A Zones with Base Flood Elevations and Floodways Established. In the A zones where base flood elevations have been provided and floodways have been established, the development may not increase the surface water elevation of the base flood at any point.
7. Floodways. Located within areas of special flood hazard are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and erosion potential, the following provisions apply:
a. 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 practice that the proposed encroachment would not result in any increase in flood levels during the occurrence of the base flood discharge.
b. Construction or reconstruction of residential structures is prohibited within designated floodways, except for: (i) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and (ii) 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 included in the 50 percent.
c. If the provisions of this section are satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section.
8. Water-Dependent Works. For water-dependent utilities and other installations which by their very nature must be in the flood fringe and/or floodway (such uses as, but not limited to, roads, bridges, marinas, dams for domestic/industrial water supply, flood control and/or hydroelectric production; water diversion structures and facilities for water supply, irrigation, and/or fisheries enhancement; flood water and drainage pumping plants and facilities; hydroelectric generating facilities and appurtenant structures; structural and nonstructural flood damage reduction facilities, and stream bank stabilization structures and practices), these provisions apply:
a. The applicant shall supply convincing evidence that a flood fringe and/or floodway location is necessary in view of the objectives of the proposal; and provided further, that the proposal is consistent with other provisions of this title and relevant local, state and federal regulations.
b. In all instances of locating utilities and other installations in floodway locations, project design must incorporate flood-proofing certified by a professional civil engineer registered as such by the state of Washington to be capable of withstanding 100-year flood flows and velocities.
c. For any works that impound water, the applicant shall provide documentation of easements, flowage rights or ownership of the impoundment area and certification by a professional civil engineer registered as such by the state of Washington that the works will cause no increase in the 100-year flood elevation outside the impoundment areas and that the works and associated impoundment area will not impair the ability of natural drainage ways to drain flood waters adequately during a flooding event.
9. Standards for Shallow Flooding Areas (AO Zones). Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these zones range from one to three feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. In these areas, the following provisions apply:
a. 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 adjacent grade to the structure, one foot or more above the depth number specified in feet on the community’s FIRM (at least three feet above the highest adjacent grade to the structure if no depth number is specified).
b. 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 FIRM (at least three 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.
c. Require adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures.
d. Recreational vehicles placed on sites within AO Zones on the community’s FIRM either:
i. Be on the site for fewer than 180 consecutive days;
ii. Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions. (Ord. 07-015 § 4, 2007).
21.30.100 Additional requirements.
A. In all storage areas designated on the FIRM, there shall be no net loss of flood storage or infiltration capacity.
B. No development shall be allowed which removes flood storage volume unless an equal volume of storage as defined by the pre-development ground surface and the base flood elevation is provided in the immediate area of the proposed development to compensate for the volume of storage which is lost (compensatory storage). Excavation below the ground water table shall not constitute an equal volume of storage.
C. No obstruction shall be permitted in any storage area which restricts or diminishes flood water conveyance capacity or floodway characteristics. (Ord. 07-015 § 4, 2007).
21.30.110 Critical facilities.
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 (Shaded Zone X), whichever is higher. Access to and from the critical facility should also be protected to the height utilized above. Flood-proofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into flood waters. 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. 07-015 § 4, 2007).