14-1-7: HABITAT IMPACTS:

   A.   Nondevelopment Activities: Activities that do not meet the definition of "development" are allowed in the regulatory floodplain without the need for a floodplain development permit under this chapter, provided all other federal, state, and local requirements are met. The following are examples of activities not considered development or "manmade changes to improved or unimproved real estate".

      1.   Routine maintenance of landscaping that does not involve grading, excavation, or filling;

      2.   Removal of noxious weeds and hazard trees and replacement of nonnative vegetation with native vegetation;

      3.   Normal maintenance of structures, such as reroofing and replacing siding, provided such work does not qualify as a substantial improvement;

      4.   Normal maintenance of aboveground utilities and facilities, such as replacing downed power lines and utility poles;

      5.   Normal street and road maintenance, including filling potholes, repaving, and installing signs and traffic signals, but not including expansion of paved areas; and

      6.   Normal maintenance of a levee or other flood control facility prescribed in the operations and maintenance plan for the levee or flood control facility are allowed in the regulatory floodplain without need for a floodplain development permit. Normal maintenance does not include repair from flood damage, expansion of the prism, expansion of the face or toe or addition for protection on the face or toe with rock armor.

   B.   Activities Allowed With A Floodplain Permit: The following activities are allowed in the regulatory floodplain without the habitat impact assessment required under subsection C of this section, providing all other requirements of this chapter are met, including obtaining a floodplain development permit:

      1.   Repairs or remodeling of an existing structure, provided that the repairs or remodeling are not a substantial improvement or a repair of substantial damage.

      2.   Expansion of an existing structure that is no greater than ten percent (10%) beyond its existing footprint, provided that the repairs or remodeling are not a substantial improvement or a repair of substantial damage. This measurement is counted cumulatively from the effective date hereof. If the structure is in the floodway, there shall be no change in the dimensions perpendicular to flow.

      3.   Activities with the sole purpose of creating, restoring or enhancing natural functions associated with floodplains, streams, lakes, estuaries, marine areas, habitat, and riparian areas that meet federal and state standards, provided the activities do not include buildings, liquid or gas storage tanks, or impervious surfaces.

      4.   Development of open space and recreational facilities, such as parks, trails, and hunting grounds, that do not include structures, fill, impervious surfaces or removal of more than five percent (5%) of the native vegetation on that portion of the property in the regulatory floodplain.

      5.   Repair to on site septic systems provided the ground disturbance is the minimum necessary.

   C.   Habitat Impact Assessment: Unless allowed under subsections A and B of this section, a permit application to develop in the regulatory floodplain shall include an assessment of the impact of the project on federal, state or locally protected species and habitat, water quality and aquatic and riparian habitat. The assessment shall be:

      1.   A biological evaluation or biological assessment developed per 50 CFR 402.12 to initiate federal interagency consultation under endangered species act section 7(a)(2); or

      2.   Documentation that the activity fits within section 4(d) of the endangered species act; or

      3.   Documentation that the activity fits within a habitat conservation plan approved pursuant to section 10 of the endangered species act, where any such assessment has been prepared or is otherwise made available; or

      4.   An assessment prepared in accordance with "Regional Guidance For Floodplain Habitat Assessment And Mitigation", FEMA region X, 2010. The assessment shall determine if the project would adversely affect:

         a.   Species that are federal, state or local listed as threatened or endangered,

         b.   The primary constituent elements for critical habitat, when designated,

         c.   Essential fish habitat designated by the national marine fisheries service,

         d.   Fish and wildlife habitat conservation areas,

         e.   Other protected areas and elements necessary for species conservation.

   D.   Habitat Mitigation Plan:

      1.   If the assessment conducted under subsection C of this section concludes the project is expected to have an adverse effect on water quality and/or aquatic or riparian habitat or habitat functions, the applicant shall provide a plan to mitigate those impacts, in accordance with "Regional Guidance For Floodplain Habitat Assessment And Mitigation", FEMA region X, 2010.

         a.   If the project is located outside the protected area, the mitigation plan shall include such avoidance, minimization, restoration, or compensation measures as are appropriate for the situation.

         b.   No new stream crossings are allowed within the special flood hazard zone, but outside the protected area.

         c.   If the project is located in the protected area, the mitigation plan shall stipulate avoidance measures as are needed to ensure that there is no adverse effect during any phase of the project.

      2.   The plan's habitat mitigation activities shall be incorporated into the proposed project. The floodplain development permit shall be based on the redesigned project and its mitigation components.

      3.   The floodplain administrator shall not issue a certification of use or a certificate of occupancy until all work identified in the biological evaluation, biological assessment, or mitigation plan has been completed or the applicant has provided the necessary assurance that unfinished portions of the project will be completed. (Ord. 913, 9-28-2011)

14-1-8: ADMINISTRATION:

   A.   Designation Of Flood Damage Prevention Chapter Administrator: The city of Orting hereby appoints the city administrator or his/her designee to administer and implement the provisions of this chapter, and is hereinafter referred to as the floodplain administrator.

   B.   Duties Of The Floodplain Administrator: Duties of the floodplain administrator shall include, but not be limited to:

      1.   Review all floodplain development permits to determine that the permit requirements of this chapter have been satisfied.

      2.   Review all floodplain 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, including those local, state or federal permits that may be required to assure compliance with the endangered species act and/or other appropriate state or federal laws.

      3.   Review all floodplain development permits to determine if the proposed development is located in the protected area. If located in the protected area, ensure that the provisions of this chapter are met.

      4.   Ensure that all development activities within the regulatory floodplain of the jurisdiction of the city of Orting meet the requirements of this chapter.

      5.   Inspect all development projects before, during and after construction to ensure compliance with all provisions of this chapter, including proper elevation of the structure.

      6.   Maintain for public inspection all records pertaining to the provisions of this chapter on a permanent basis.

      7.   Submit reports as required for the national flood insurance program.

      8.   Notify FEMA of any proposed amendments to this chapter.

      9.   Cooperate with state and federal agencies to improve flood and other technical data and notify FEMA of any new data that would revise the FIRM.

   C.   Records:

      1.   Where base flood elevation data have been obtained pursuant to this chapter, the administrator shall obtain, record, and maintain the actual "finished construction" elevation. This information shall be recorded on a current FEMA elevation certificate (FEMA form 81-31), signed and sealed by a professional land surveyor, currently licensed in the state of Washington.

      2.   For all new or substantially improved dry floodproofed nonresidential structures, where base flood elevation data has been obtained pursuant to this chapter, the administrator shall obtain, record and maintain the elevation (in relation to the datum of the effective FIRM) to which the structure was floodproofed. This information shall be recorded on a permanent basis on a current FEMA floodproofing certificate (FEMA form 81-65), professional engineer, currently licensed in the state of Washington.

   D.   Development Permits: All required land use and building permits granted by the city shall be subject to the provisions of this chapter.

      1.   Establishment; 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 set forth in this chapter, and for all development including fill and other activities, also as set forth in this chapter.

      2.   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:

         a.   Elevations of the area of development in relation to mean sea level (such as a contour map) for both existing and proposed development;

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

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

         d.   Elevations of the 10-, 50-, 100-, and 500-year floods, where the data are available;

         e.   The riparian habitat zone shall be delineated on the site plan for all development proposals within three hundred feet (300') of any stream or shoreline;

         f.   Certification by a registered professional surveyor that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in subsection 14-1-9B2 of this chapter;

         g.   Existing and proposed infrastructure. If the proposed project includes a new structure, substantial improvement, or repairs to a substantially damaged nonresidential structure that will be dry floodproofed, the application shall include the FPE for the building site and the elevation in relation to the datum of the effective FIRM to which the structure will be dry floodproofed and a certification by a registered professional engineer or licensed architect that the dry floodproofing methods meet the floodproofing criteria;

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

         i.   Description of the extent to which a stream, lake, or other water body, including its shoreline, will be altered or relocated as a result of the proposed development;

         j.   Designated fish and wildlife habitat conservation areas, and habitat areas identified for conservation or protection under state or federal or local laws or regulations (e.g., endangered species act, Magnuson-Stevens fishery conservation and management act, growth management act, shorelines management act, priority habitat and species list);

         k.   Existing native vegetation and proposed revegetation;

         l.   Documentation that the applicant will apply for all necessary permits required by federal, state, or local law. The application shall include written acknowledgment that the applicant understands that the final certification of use or certificate of occupancy will be issued only if the applicant provides copies of the required federal, state, and local permits or letters stating that a permit is not required. The floodplain permit is not valid if those other permits and approvals are not obtained prior to any ground disturbing work or structural improvements; and

         m.   Acknowledgment by the applicant that representatives of any federal, state or local unit of government with regulatory authority over the project are authorized to enter upon the property to inspect the development.

      3.   Construction Stage: If the floodplain encroaches five feet (5') into the subject property line, then a flood floor elevation certificate will be required. Upon placement of the lowest floor, or floodproofing by whatever means, it shall be the duty of the permit holder to submit to the floodplain management administrator a certification of the elevation of the lowest floor or floodproofed elevation, as built in relation to mean sea level. A registered land surveyor who is authorized to certify such information in the state of Washington shall prepare said certification. Any work undertaken prior to the submission of the certification shall be at the permit holder's risk.

The administrator shall review the lowest floor elevation and floodproofing certificate. Should these documents be found not in conformance with the requirements of this chapter the permit holder shall immediately cease further work, and shall correct the deficiencies. Failure of the permit holder to submit the surveyed lowest floor elevation and floodproofing certificates, and failure to correct said deficiencies required, shall be the cause to issue a stop work order for the project.

   E.   Administration By City; Grant Or Deny Permits: The city is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions.

   F.   Duties And Responsibilities Of City: Duties of the city shall include, but not be limited to:

      1.   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 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.

   G.   Certificate Of Occupancy:

      1.   A certification of use for the property or a certificate of occupancy for a new or substantially improved structure or an addition shall not be issued until:

         a.   The permit applicant provides a properly completed, signed and sealed elevation or floodproofing certificate showing finished construction data as required by this chapter;

         b.   If a mitigation plan is required by this chapter, all work identified in the plan has been completed according to the plan's schedule;

         c.   The applicant provides copies of all required federal, state, and local permits noted in the permit application instructions; and

         d.   All other provisions of this chapter have been met.

      2.   The floodplain administrator may accept a performance bond or other security that will ensure that unfinished portions of the project will be completed after the certification of use or certificate of occupancy has been issued.

   H.   Floodplain Development Permit Expiration: If there has been no start of construction, a floodplain development permit shall expire one hundred eighty (180) days after the date of issuance. Where the applicant documents a need for an extension beyond this period due to conditions beyond the applicant's control, the floodplain administrator may authorize one or more extensions.

   I.   Variance Procedure: Variances from the provisions of this chapter shall be processed as described in title 15 of this code. Approved variances shall permit structures to be built with a lowest floor elevation below the base flood elevation and shall assert that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. The findings and conclusions of approved variances shall be recorded with the Pierce County auditor and shall run with the land.

      1.   Variance Considerations: In considering such variances, the hearings examiner shall consider the following factors:

         a.   The danger that materials may be swept onto other lands at the risk of injury to 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 availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;

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

         g.   The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters and the effects of wave action, if applicable, expected at the site; and

         h.   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.

      2.   Conditions For Variances:

         a.   Upon a determination that the proposed repair or rehabilitation of a historic structure will not preclude the structure's continued designation as a historic structure, and the variance is the minimum necessary to preserve the historic character and design of the structure.

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

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

         d.   A determination that failure to grant the variance would result in exceptional hardship to the applicant.

         e.   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.

         f.   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 in this section and otherwise complies with subsections of this chapter. (Ord. 2017-1010, 3-6-2017)

14-1-9: 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 including manufactured housing 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 "Manufactured 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 at least one (1) foot above the base flood elevation.

      3.   Utilities:

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

         b.   Water wells shall be located on high ground that is not in the floodway;

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

         d.   On site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. A habitat impact assessment shall be conducted in accordance with subsection 14-1-7B5 of this chapter as a condition of approval of an on site waste disposal system to be located in the regulatory floodplain.

      4.   Subdivision Proposals 1 : This section applies to all subdivision proposals, short subdivisions, short plats, planned developments, and new and expansions to manufactured housing parks.

         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 flood damage;

         c.   All subdivision proposals shall have adequate drainage provided to reduce exposure to 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 fifty (50) lots or five (5) acres (whichever is less);

         e.   The proposed subdivision should have one or more new lots in the regulatory floodplain set aside for open space use through deed restriction, easement, subdivision covenant, or donation to a public agency. The density of the development in the portion of the development outside the regulatory floodplain may be increased to compensate for the amount of land in the regulatory floodplain preserved as open space in accordance with Orting development regulations. Optionally, the city may choose to accept a mitigation contribution in lieu of dedicated open space; and

         f.   The final recorded subdivision plat shall include a notice that part of the property is in the SFHA, riparian habitat zone and/or channel migration area, as appropriate.

      5.   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 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 (2') above the highest adjacent grade in these zones may result in higher insurance rates.

      6.   Shoreline Modifications:

         a.   The proposed project must be designed and located so that new structural flood protection is not needed.

         b.   Bank stabilization measures must be minimized to the maximum extent possible. If bank stabilization measures are necessary, bioengineered armoring of stream banks must be used per the "Integrated Streambank Protection Guidelines" 2003.

      7.   Hazardous Materials: No new development shall create a threat to public health, public safety, or water quality. Chemicals, explosives, gasoline, propane, buoyant materials, animal wastes, fertilizers, flammable liquids, pollutants, or other materials that are hazardous, toxic, or a threat to water quality are prohibited from the regulatory floodplain. This prohibition does not apply to small quantities of these materials kept for normal household use. This prohibition does not apply to the continued operations of existing facilities and structures, reuse of existing facilities and structures, or functionally dependent facilities or structures. If the proposed project cannot meet these requirements, then a habitat assessment must be conducted in accordance with section 14-1-7 of this chapter.

   B.   Specific Standards: In all areas of special flood hazards where base flood elevation data have been provided as set forth in subsection 14-1-6B of this chapter, the following provisions are required:

      1.   Residential Construction:

         a.   New construction, substantial improvements and/or reconstruction due to substantial damage of any residential structure, including machinery and equipment shall have the lowest floor, including basement, elevated one foot (1') or more above base flood elevation.

         b.   Fully enclosed areas below the lowest floor shall be used solely for parking of vehicles, building access, or storage. These enclosed areas shall be designed and constructed to allow 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:

            (1)   A minimum of two (2) 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.

            (2)   The bottom of all openings shall be no higher than one foot (1') above grade.

            (3)   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 improvements of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated one foot (1') or more above the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

         a.   Be floodproofed so that below one foot (1') 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;

         d.   Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection B1b of this section; and

         e.   Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot (1') below the floodproofed level (e.g., a building floodproofed to 1 foot above the base flood level will be rated as at the base flood level).

      3.   Critical Facility: Construction of new critical facilities shall be, to the extent possible, located outside the limits of the SFHA. 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 to three feet (3') or more above the level of the base flood elevation at the site. 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 maximum extent possible.

      4.   Manufactured Homes: All manufactured homes to be placed or substantially improved within zones A1-30, AH, and AE on the community's FIRM shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is one foot (1') or more above the base flood elevation; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of subsection A.1.b. of this section.

      5.   Site Design:.

         a.   Structures and other development shall be located to avoid flood damage.

            (1)   If a lot has a buildable site out of the regulatory floodplain, all new structures shall be located in that area, when possible.

            (2)   The structure shall be aligned parallel with the direction of flood flows where practicable.

            (3)   If a lot does not have a buildable site out of the regulatory floodplain, all new structures, pavement, and other development must be sited in the location that has the least impact on habitat by locating the structures as far from the water body as possible or placing the structures on the highest land on the lot.

            (4)   A minimum setback of fifteen feet (15') from the protected area shall be required for all structures.

            (5)   If the proposed project does not meet the criteria of this section, a habitat impact assessment shall be conducted pursuant to subsection 14-1-7C of this chapter and, if necessary, a habitat mitigation plan shall be prepared and implemented pursuant to subsection 14-1-7D of this chapter.

         b.   All new development shall be designed and located to minimize the impact on flood flows, flood storage, water quality, and habitat.

            (1)   Stormwater and drainage features shall incorporate LID BMPs in accordance with section 9-5A-9D of this code unless, based on the Stormwater Management Manual, LID BMPs are infeasible.

            (2)   If the proposed project will create new impervious surfaces where no more than ten percent (10%) of the lot in the regulatory floodplain is covered by impervious surface, it must comply with title 9, chapter 5, "Stormwater Regulations", of this code, and mitigate adverse impacts as provided by this chapter.

            (3)   Construction or reconstruction of residential structures is prohibited within designated floodways, except for: a) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area, and b) repairs, reconstruction, or improvements which do not exceed fifty percent (50%) of the market value of the structure as specified in Washington administrative code 173-158-070.

   C.   Floodways: Located within areas of special flood hazard established in subsection 14-1-6B of this chapter are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply:

      1.   Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer or architect is provided demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practices that encroachments shall 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 which do not increase the ground floor area; and b) repairs, reconstruction or improvements to a structure, the cost of which does not exceed fifty percent (50%) of the market value of the structure either: 1) before the repair, reconstruction, or improvement is started, or 2) 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 shall not be included in the fifty percent (50%).

      3.   If subsection B of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section.

   D.   Wetlands Management: To the maximum extent possible avoid the short and long term adverse impacts associated with the destruction or modification of wetlands, especially those activities that limit or disrupt the ability of the wetland to alleviate flooding impacts. The following process should be implemented:

      1.   Review proposals for development within base floodplains for their possible impacts on wetlands located within the floodplain.

      2.   Ensure that development activities in or around wetlands do not negatively affect public safety, health, and welfare by disrupting the wetlands' ability to reduce flood and storm drainage.

      3.   Request technical assistance from the department of ecology in identifying wetland areas. Existing wetland map information from the national wetlands inventory (NWI) can be used in conjunction with the community's FIRM to prepare an overlay zone indicating critical wetland areas deserving special attention.

   E.   Native Vegetation: The site plan required in section 14-1-8 of this chapter shall show existing native vegetation.

      1.   In the riparian habitat zone, native vegetation shall be left undisturbed, except as provided in sections 7.1 and 7.2.C.

      2.   Outside the riparian habitat zone, removal of native vegetation shall not exceed thirty five percent (35%) of the surface area of the portion of the site in the regulatory floodplain. Native vegetation in the riparian habitat zone portion of the property can be counted toward this requirement.

      3.   If the proposed project does not meet the criteria of sections 7.4.A and B, a habitat impact assessment shall be conducted pursuant to section 7.7 and, if necessary, a habitat mitigation plan shall be prepared and implemented pursuant to section 7.8.

   F.   Compensatory Storage: New development shall not reduce the effective flood storage volume of the regulatory floodplain. A development proposal shall provide compensatory storage if grading or other activity eliminates any effective flood storage volume. Compensatory storage shall:

      1.   Provide equivalent volume at equivalent elevations to that being displaced. For this purpose, "equivalent elevation" means having similar relationship to ordinary high water and to the best available 10-year, 50-year and 100-year water surface profiles;

      2.   Be hydraulically connected to the source of flooding;

      3.   Provide compensatory storage in the same construction season as when the displacement of flood storage volume occurs and before the flood season begins; and

      4.   The newly created storage area shall be graded and vegetated to allow fish access during flood events without creating fish stranding sites.

   G.   Additional Standards; Crawl Space Construction For Buildings Located In Special Flood Hazard Areas:

      1.   The interior grade of a crawl space below the BFE must not be more than two feet (2') below the lowest adjacent exterior grade (LAG), shown as D in figure 3 of this section.

      2.   The height of the below grade crawl space, measured from the interior grade of the crawl space to the top of the crawl space foundation wall must not exceed four feet (4') (shown as L in figure 3 of this section) at any point. The height limitation is the maximum allowable unsupported wall height according to the engineering analyses and building code requirements for flood hazard areas.

      3.   There must be an adequate drainage system that removes floodwaters from the interior area of the crawl space. 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.

      4.   The velocity of floodwaters at the site should not exceed five feet (5') per second for any crawl space. For velocities in excess of five feet (5') per second, other foundation types should be used.

      5.   Any building utility systems within the crawl space must be elevated above BFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions. Ductwork, in particular, must either be placed above the BFE or sealed from floodwaters.

      6.   Portions of the building below the BFE must be constructed with materials resistant to flood damage. This includes not only the foundation walls of the crawl space used to elevate the building, but also any joists, insulation, or other materials that extend below the BFE.

      7.   Below grade crawl space construction in accordance with the requirements listed above will not be considered basements.

   H.   Critical Facilities:

      1.   Construction of new critical facilities shall be, to the extent possible, located outside the limits of the regulatory floodplain (SFHA). 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 maximum extent possible.

      2.   Construction of new critical facilities in the regulatory floodplain shall be permissible if no feasible alternative site is available, provided:

         a.   Critical facilities shall have the lowest floor elevated three feet (3') above the base flood elevation or to the height of the 500-year flood, whichever is higher. If there is no available data on the 500-year flood, the permit applicants shall develop the needed data in accordance with FEMA mapping guidelines.

         b.   Access to and from the critical facility shall be protected to the elevation of the 500-year flood.

(Ord. 913, 9-28-2011; amd. 2017-1006, 2-22-2017; Ord. 2019-1057, 1-8-2020; Ord. 2021-1072, 1-27-2021)

 

Notes

1	1. See title 12 of this code.

14-1-10: STANDARDS FOR PROTECTION OF STRUCTURES:

   A.   Applicability: All permit applications will be reviewed to determine whether proposed building sites will be reasonably safe from flooding. If a proposed building site is in a flood prone area, all new construction and substantial improvements shall: 1) be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, 2) be constructed with materials resistant to flood damage, 3) be constructed by methods and practices that minimize flood damages, and 4) be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

This section's protection requirement applies to all new structures and substantial improvements, which include:

      1.   Construction or placement of a new structure.

      2.   Reconstruction, rehabilitation, or other improvement that will result in a substantially improved building.

      3.   Repairs to an existing building that has been substantially damaged.

      4.   Placing a manufactured home on a site.

      5.   Placing a recreational vehicle or travel trailer on a site for more than one hundred eighty (180) days.

   B.   Flood Protection Standards:

      1.   All new structures and substantial improvements shall have the lowest floor, including basement, elevated above the FPE.

      2.   The structure shall be aligned parallel with the direction of flood flows where practicable.

      3.   The structure shall be anchored to prevent flotation, collapse, or lateral movement of the structure.

      4.   The structure shall be aligned parallel with the direction of flood flows where practicable.

      5.   The structure shall be anchored to prevent flotation, collapse, or lateral movement of the structure.

      6.   All materials below the FPE shall be resistant to flood damage and firmly anchored to prevent flotation.

      7.   Materials harmful to aquatic wildlife, such as creosote, are prohibited below the FPE.

      8.   Electrical, heating, ventilation, ductwork, plumbing, and air conditioning equipment and other service facilities shall be elevated above the FPE. Water, sewage, electrical, and other utility lines below the FPE shall be constructed so as to prevent water from entering or accumulating within them during conditions of flooding.

      9.   Fully enclosed areas below the lowest floor that are subject to flooding shall be used only for parking, storage, or building access and 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 shall either be certified by a registered professional engineer or licensed architect and/or meet or exceed the following minimum criteria:

         a.   A minimum of two (2) openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.

         b.   The bottom of all openings shall be no higher than one foot (1') above grade.

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

   C.   Nonresidential Construction: New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall be elevated in accordance with this chapter. As an alternative to elevation, a new or substantial improvement to a nonresidential structure and its attendant utility and sanitary facilities, may be dry floodproofed in A zones. The project must meet the following:

      1.   The structure is not located in zones V, V1-30, or VE; and

      2.   Below the FPE the structure is watertight with walls substantially impermeable to the passage of water; and

      3.   The structural components are capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

      4.   The plans are certified by a registered professional engineer or licensed 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 floodplain administrator as set forth in this chapter.

   D.   Manufactured Homes: All manufactured homes to be placed or substantially improved on sites shall be:

      1.   Elevated on a permanent foundation in accordance with this chapter, and

      2.   Securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. Methods of anchoring may include, but are not to be limited to, use of over the top or frame ties to ground anchors. This requirement is in addition to other applicable anchoring requirements for resisting wind forces. (For more detailed information, see the "FEMA Guidebook" p-85.)

   E.   Recreational Vehicles: Recreational vehicles placed on sites shall:

      1.   Be on the site for fewer than one hundred eighty (180) consecutive days, or

      2.   Be fully licensed and ready for highway use, on their wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions.

   F.   Appurtenant Structures: A structure which is on the same parcel of property as the principal structure and the use of which is incidental to the use of the principal structure and is not used for human habitation may be exempt from the elevation requirement of this chapter, provided:

      1.   It is used only for parking or storage;

      2.   It is constructed and placed on the building site so as to offer minimum resistance to the flow of floodwaters;

      3.   It is anchored to prevent flotation which may result in damage to other structures;

      4.   All portions of the structure below the FPE must be constructed of flood resistant materials;

      5.   Service utilities such as electrical and heating equipment meet the standards of this chapter;

      6.   It has openings to allow free flowage of water that meet the criteria in this chapter;

      7.   The project meets all the other requirements of this chapter.

   G.   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 outside the floodway and shall be protected to the FPE;

      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.   New on site waste disposal systems are prohibited in the city.

   H.   Subdivision 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 authorized source, it shall be generated for subdivision proposals and other proposed developments which contain at least fifty (50) lots or five (5) acres (whichever is less). (Ord. 2017-1009, 3-1-2017)