A. 
Purpose and Intent. The purpose of this section is to promote the public health, safety, and general welfare, and to protect the ecological functions of floodplains and riparian areas by managing, restricting, and regulating development in areas of the city designated as floodplains and in other areas which are important to maintaining the ecological and hydrologic functions of floodplains. Specifically, this section is intended to accomplish the following objectives:
1. 
Protect human life, health and property from the dangers of flooding;
2. 
Minimize the need for publicly funded and hazardous rescue efforts to save those who are isolated by floodwaters;
3. 
Minimize expenditure of public money for costly flood damage repair and flood control projects;
4. 
Minimize disruption of commerce and governmental services;
5. 
Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets, and bridges located in the floodplain;
6. 
Maintain a stable tax base by providing for the sound use of flood prone areas so as to minimize future flood blight areas;
7. 
Encourage that those who occupy areas subject to flooding and channel migration assume responsibility for their actions;
8. 
Ensure the city's residents and property owners can obtain flood insurance through participation in the National Flood Insurance Program;
9. 
Maintain or improve the quality, availability, and ecological functions of rivers, streams, lakes, wetlands, ground water, estuaries, and other water resources;
10. 
Retain the natural channel, shoreline, and floodplain creation processes and other natural floodplain functions that protect, create, and maintain habitat for threatened and endangered species;
11. 
Prevent or minimize loss of hydraulic, geomorphic, and ecological functions of floodplains and stream channels.
B. 
Applicability. Except as explicitly exempt, this chapter shall apply to all development as follows:
1. 
Floodplain Management Areas. This chapter shall apply to all areas mapped as or meeting the definition of a floodplain management area.
2. 
Other Areas. For areas outside of, or not otherwise meeting the definition of, a floodplain management area, all new buildings, and substantial improvements to existing buildings, shall comply with the requirements of BMC § 14.15.430 (Construction standards).
(Ord. 1903 § 2 (Exh. A), 2021; Ord. 1933 § 1 (Exh. A), 2023)
A. 
Designation. The following areas and features are designated as floodplain management areas:
1. 
Flood hazard area. The flood hazard area, or floodplain, is the land subject to inundation by the base flood. Flood hazard areas are designated on flood insurance rate maps with the letters "A" or "V" including AE, AO, AH, A1-99, and VE.
2. 
Protected area. Includes lands that lie within the boundaries of a floodway, riparian habitat zone, or channel migration area.
3. 
Riparian habitat zone. The water body, and adjacent land areas, likely to support aquatic and riparian habitat. For purposes of administering this section, the riparian habitat zone shall be any water body capable of being classified as a type "S," "F," "Np," or "Ns" water body, together with its associated riparian buffer, as described in this chapter.
4. 
Floodway. Within the city of Burlington the floodway consists of the Skagit River and all areas riverward of the toe of the dikes and levees along the Skagit River.
5. 
Chanel migration zone. Within the city of Burlington the channel zone shall be limited to the Skagit River and all areas riverward of the toe of the dikes and levees along the Skagit River.
6. 
Special flood risk zone. The special flood risk zone includes the following floodplain areas:
a. 
Gages Slough, including wetlands and deep water habitat areas; or
b. 
Areas with a ground elevation three feet or more below the base flood elevation that are hydraulically connected to Gages Slough through a channel, watercourse, or other topographical feature that provides a continuous path capable of conveying floodwaters with an elevation three feet or more below the base flood elevation; or
c. 
Areas within 300 feet of the landward toe of dikes and levees along the Skagit River, excluding floodways.
7. 
Other areas. Other areas may be designated as floodplain management areas if the director determines, based on credible evidence, they are at equivalent risk of flooding to mapped floodplain areas. In making such determinations the director shall consider elevation, survey, or hydrologic data affecting the potential of the area for flooding. Only information prepared by a licensed surveyor, or engineer, or otherwise meeting the criteria for best available science in chapter 365-195 WAC shall be considered.
B. 
Mapping. The director shall be responsible for maintaining the city's floodplain maps and data. The following maps, data sources, and procedures shall be used to identify floodplains and floodplain management areas:
1. 
Valid, adopted, and up-to-date flood insurance rate maps (FIRM). Presently the following maps provide information on the city of Burlington:
a. 
The flood insurance rate map (FIRM) for the city of Burlington dated January 3, 1985, and identified by community panel number 530153 0001 B;
b. 
The flood insurance rate map (FIRM) for Skagit County dated January 3, 1985, and identified by community panel number 530151 0250 C;
c. 
The flood insurance rate map (FIRM) for Skagit County dated September 29, 1989, and identified by community panel number 530151 0235 D.
2. 
Any other valid, adopted, and up-to-date FIRM depicting areas within the city of Burlington may be used for purposes of complying with this chapter.
3. 
The flood insurance study (FIS) for the city of Burlington, Washington, Skagit County, dated July 3, 1984, and the flood insurance study for Skagit County, Washington Unincorporated Areas dated September 29, 1989. In the event an updated FIS depicting areas within the city of Burlington is adopted it may be used for purposes of complying with this chapter.
4. 
The director shall make interpretations where needed as to the exact location and boundaries of the floodplain management area and floodplain. Interpretations may be necessary where there appears to be a conflict between the mapped location of the floodplain management area or floodplain, and the actual field conditions based on ground elevations or base flood elevations.
5. 
Any approved FEMA "letter of map amendment" or "letter of map revision."
6. 
The base flood elevation for floodplain areas within the city of Burlington delineated as a "zone AH" or "zone AO" shall be the corresponding elevation (or depth) identified on the applicable FIRM. Where base flood depths are not available for areas identified as a "zone AO" the base flood elevation shall be considered to be two feet above the highest grade adjacent to the structure.
7. 
The flood protection elevation (FPE) shall be determined as follows:
a. 
New structures and developments and substantial improvements to existing structures or developments: base flood elevation plus one foot of additional elevation;
b. 
New critical facilities and substantial improvements to existing structures or developments: base flood elevation plus three feet of additional elevation.
8. 
The floodways shall be delineated as shown on the applicable FIRM. In all cases the floodway shall, at a minimum, include the Skagit River and all areas riverward of the toe of the dikes and levees along the Skagit River.
9. 
Where base flood elevation and floodway data have not been provided in floodplain areas, the director shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal or state agency, or, in the absence of information from a federal or state agency, another relevant source provided such information is consistent with the criteria for best available science in chapter 365-195 WAC.
C. 
New Regulatory Data and Map Revisions.
1. 
All requests to revise or change floodplain mapping or hazard data, including requests for a letter of map revision and a conditional letter of map revision, shall be subject to the following:
a. 
Community acknowledgment forms shall not be signed for requests based on filling or other development, unless the filling or development was conducted in full compliance with the requirements of this chapter and all other applicable regulatory requirements;
b. 
Requests to revise or change a floodway delineation shall not be approved until FEMA has issued a conditional letter of map revision approving the change.
2. 
Site-specific base flood elevation data shall be generated for subdivision proposals involving more than 50 lots or five acres, whichever is less, if no applicable base flood elevation data or mapping is available.
3. 
If areas are added to the city of Burlington through annexation that are adjacent to the Skagit River, and if such areas do not meet the definition of a disconnected migration area as defined in WAC 173-26-221(3)(b), the floodway associated such areas shall include the Skagit River and one-half the mapped floodplain at any point.
4. 
All new hydrologic and hydraulic flood studies conducted pursuant to this section shall consider future conditions and the cumulative effects from anticipated land use changes in accordance with Regional Guidance for Hydrologic and Hydraulic Studies in Support of the Model Ordinance for Floodplain Management under the National Flood Insurance Program and the Endangered Species Act, FEMA Region 10, 2012.
5. 
In weighing conflicting official information sources regarding channel migration zones, floodways, future flood conditions, and the location of riparian habitat areas, the most restrictive data available at the time the decision is rendered shall be used.
D. 
All floodplain mapping, data, studies, regulations, and other information shall be maintained by the community development director and shall be available during regular city business hours, 833 South Spruce Street.
(Ord. 1903 § 2 (Exh. A), 2021)
A. 
Permit Required. Unless explicitly identified as exempt, a flood development permit shall be required for all development in a floodplain management area. An exemption from having to obtain a permit shall not be construed as an exemption from other applicable requirements. All development in a floodplain management area shall be subject to the requirements of this chapter unless explicitly exempt.
B. 
Exempt Development. The following development shall not require a flood development permit:
1. 
Routine maintenance of landscaping that does not involve grading, excavation, or filling;
2. 
Removal of noxious weeds and hazard trees and replacement of non-native vegetation with native vegetation;
3. 
Normal maintenance of structures, such as re-roofing and replacing siding, provided such work does not qualify as a substantial improvement;
4. 
Normal maintenance of above-ground utilities and facilities, such as replacing downed power lines and utility poles;
5. 
Normal street and road maintenance, including filling potholes, repaving, installing signs and traffic and traffic lights, but not including the expansion of existing paved areas;
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;
7. 
Plowing and other normal farm practices (other than structures or filling) on farms in the floodplain management areas and in existence as of the effective date of the ordinance codified in this chapter do not require a floodplain development permit. Clearing additional land for agriculture after the date of the ordinance codified in this chapter will require a flood plain development permit; and
8. 
The placement or storage of a recreational vehicle on a lot or site for less than 180 days provided:
a. 
Recreational vehicles shall be used only for travel and recreational purposes. Recreational vehicles shall not be used as a dwelling unit or a place of permanent habitation and shall under no circumstances be occupied for periods of 30 days or more;
b. 
All recreational vehicles shall 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.
C. 
Application Requirements. Applications for flood development permits shall be made on forms provided by the director and shall include all of the information required by the form in addition to all of the items listed below. Only applications including all of the information required by this section shall be deemed complete for purposes of complying with this chapter and BMC Title 14A. A complete application shall, at a minimum, include:
1. 
One or more site plans, drawn to scale, showing:
a. 
The location, boundaries, dimensions, and elevations of the development site;
b. 
Names and location of all lakes, water bodies, watercourses, wetlands, rivers and drainage facilities within 300 feet of the development site;
c. 
The elevations of the 10-, 50-, 100‑, and 500-year floods, where the data are available;
d. 
The boundaries of the floodplain, special flood risk area, floodway, riparian habitat zone, and channel migration area;
e. 
The proposed drainage system including, but not limited to, storm sewers, overland flow paths, detention facilities, and roads;
f. 
Existing and proposed structures, fill, pavement and other impervious surfaces, and sites for storage of materials;
g. 
All wetlands;
h. 
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);
i. 
Existing native vegetation, significant trees, and any proposed revegetation, planting, or mitigation areas.
2. 
If the development involves grading, excavation, or filling, the site plan shall include post-development elevation contours at one-foot intervals.
3. 
If the proposed development involves a new structure, substantial improvement to an existing structure, or repairs to a substantially damaged structure that will be elevated, the application shall include site elevation data and the following additional elevations. All elevation data shall be provided in relation to mean sea level and shall be prepared using the datum and methods prescribed by FEMA. Elevation data shall be submitted on an approved elevation certificate form consistent with the requirements of this chapter.
a. 
The top of bottom floor (including basement, crawlspace, or enclosure floor).
b. 
The lowest elevation of any machinery, equipment, mechanical equipment, or HVAC systems servicing the structure.
4. 
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 to which the structure will be dry floodproofed. A certification prepared by a registered professional engineer or licensed architect shall be submitted and shall document that the dry floodproofing methods employed are consistent with the floodproofing criteria and requirements in this chapter.
5. 
The proposed project must be designed and located so that new structural flood protection is not needed.
6. 
The application shall include a description of the extent to which a stream, lake, watercourse, or other water body, including its shoreline, will be altered or relocated as a result of the proposed development.
7. 
The application shall include 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 inspection 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.
8. 
The application shall include 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.
9. 
Any other information requested by the director necessary to demonstrate compliance with the requirements of this chapter, other Burlington Municipal Code requirements, or any other applicable state or federal regulatory requirements.
D. 
Approval Criteria. Flood development permits shall be subject to the approval criteria and development regulations identified in this section. The city shall have the authority to condition floodplain permits in order to ensure full compliance with this section and to ensure all development is reasonably safe from flooding. No permit shall be issued or approved unless the proposal is consistent with the following requirements.
E. 
Review Process. Unless otherwise stated in this section, flood development permits shall be processed in accordance with the review procedures prescribed in BMC Title 14A.
F. 
Appeals. Flood development permit decisions may be appealed in accordance with the procedures prescribed in BMC Title 14A.
G. 
Time Limits. Flood development permits shall be subject to the following time limits:
1. 
Flood development permits associated with a building or grading permit shall be subject to the time limit and expiration date applicable to the building or grading permit.
2. 
Flood development permits associated with a land use permit or platting decision shall be subject to the time limit and expiration date applicable to the land use permit or platting decision.
3. 
For flood development permits not associated with another permit type, the development authorized by the permit shall begin within 180 days and all development shall be completed within two years.
(Ord. 1903 § 2 (Exh. A), 2021; Ord. 1933 § 1 (Exh. A), 2023)
A. 
Applicability. The provisions of this section shall apply to all development in the floodplain.
B. 
General Regulations.
1. 
All utilities providing services such as sanitary sewer, gas, electricity, and potable water shall located, designed, and constructed to prevent or minimize flood damage;
2. 
New development requiring potable water shall be connected to a public water supply system;
3. 
Private water systems and wells shall not be used as a source of potable water for new development. All wells within the floodplain management area shall be subject to the following:
a. 
Wells shall be located outside the floodway; and
b. 
Wells and associated water system components shall be protected to the flood protection elevation to prevent floodwaters from entering the well;
4. 
New development that generates, or has the potential to generate, wastewater shall be connected to the municipal sewer system. New on-site waste disposal systems are prohibited in the floodplain;
5. 
Development shall not create a threat to public health, safety, or negatively affect water quality;
6. 
No construction, development, or substantial improvements shall be permitted if the cumulative floodwater displacement effect of the proposed development, combined with all other existing and proposed development, would cause the base flood elevation to increase by more than one foot at any location in the city. A displacement analysis, prepared by a licensed engineer, demonstrating compliance with this provision shall be submitted for any construction, development, or substantial improvement in flood zones A1-30 and AE.
C. 
Land Division. The following development regulations shall apply to all land divisions including short plats, subdivisions, and binding site plans:
1. 
Land divisions shall employ site design, engineering, or construction practices to minimize flood damage.
2. 
Applications for preliminary subdivision or binding site plan approval shall include a habitat assessment and mitigation plan consistent with the requirements of this chapter.
3. 
The layout and development density of proposed subdivisions and binding site plans must be consistent with the restrictions and mitigation measures identified in the habitat assessment and mitigation plan. The cluster development provisions identified in BMC Titles 16 and 17 shall be used when necessary to mitigate impacts to floodplain ecology and hydrology.
4. 
All final plats, short plats, and binding site plans shall include a note stating that the plat contains property within a floodplain management area. Notes shall also be included identifying any restrictions placed on the use or development of lots within the plat or BSP.
5. 
Stormwater management and drainage systems shall be provided consistent with the requirements of BMC Title 14 and shall incorporate LID measures in accordance with the requirements of BMC Titles 16 and 17.
6. 
For land divisions involving five acres or more or the creation of 50 or more lots, site-specific base flood elevation data shall be generated if base flood elevation data for the development site is not available from an authorized source.
D. 
Riparian Habitat Zone. The following regulations shall apply to all development in a riparian habitat zone or within 300 feet of a stream or river:
1. 
All development in the riparian habitat zone shall comply with the standards and regulations set forth in this chapter for fish and wildlife habitat conservation areas.
2. 
The site plan shall depict the location of the stream or river and the extent of the associated riparian buffer.
E. 
Site Design. The following site design regulations shall apply to all development on existing lots:
1. 
Structures and other development shall be located to avoid flood damage.
2. 
If a lot has a buildable area outside of the floodplain management area, all new structures shall be located in that area to the maximum extent possible.
3. 
If a lot does not have a buildable area outside 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 15 feet from the protected area shall be required for all structures.
5. 
Unless the development is explicitly exempt from habitat assessment and mitigation requirements a habitat impact assessment, and if necessary a mitigation plan, shall be prepared in accordance with the requirements of this chapter.
6. 
All new development shall be designed and located to minimize the impact on flood flows, flood storage, water quality, and habitat.
7. 
Stormwater and drainage features shall incorporate low impact development techniques in accordance with the requirements of BMC Title 17.
8. 
If the development will create new impervious surfaces so that more than 10 percent of the portion of the lot in the regulatory floodplain is covered by impervious surface, the applicant shall demonstrate that there will be no net increase in the rate and volume of the stormwater surface runoff that leaves the site or that the adverse impact is mitigated, as required by this chapter.
9. 
The site plan shall account for surface drainage to ensure that:
a. 
Existing and new buildings on the site will be protected from stormwater runoff; and
b. 
The project will not divert or increase surface water runoff onto neighboring properties.
F. 
Hazardous Materials. These regulations shall apply to all development involving the storage, handling, disposal, processing, or production of hazardous materials.
G. 
Critical Facilities.
1. 
New critical facilities shall not be located in a floodplain management area unless:
a. 
No feasible site exists outside the floodplain management area; or
b. 
The critical facility is necessary to provide flood protection or drainage services.
2. 
If no feasible site exists outside the floodplain management area, than critical facilities may be established within the floodplain management area subject to the following:
a. 
Critical facilities shall have the lowest floor elevated four feet above the base flood elevation or to the height of the 500-year flood, whichever is higher. If no applicable 500-year flood data exists, information shall be developed by a qualified professional in accordance with FEMA mapping guidelines and included with the permit application.
b. 
Access to and from the critical facility shall be protected to the elevation of the 500-year flood to the extent feasible.
H. 
Floodway Development. The following regulations shall apply to all development in the floodway:
1. 
All development shall be prohibited in the floodway except as follows:
a. 
Utility outfall structures authorized by the Corps of Engineers; and
b. 
The construction and maintenance of dikes and levees for flood control purposes; and
c. 
Bridges and other river crossings for transportation or utility purposes as minimally necessary for purposes of permitting an essential public facility; and
d. 
Development which is explicitly exempt from floodplain development permit requirements by BMC § 14.15.410.
2. 
The following information shall be included with any application for a permit for development in the floodway. All information shall be prepared by a licensed engineer.
a. 
A thorough hydraulic and hydrologic analysis prepared by a licensed engineer, in accordance with standard engineering practices, that the proposed development will not result in any increase in flood levels during the occurrence of the base flood discharge; and
b. 
A projection of anticipated changes to hydraulic and hydrologic conditions over the life of development. The required analysis shall be based on the best available science and shall address changes attributable to climate change and projected floodplain development. For the purpose of interpreting these requirements the term "life of the development" shall mean a period of at least 100 years;
c. 
An analysis of any impacts to flood protection structures such as dikes, levees, and outfalls;
d. 
An analysis of potential upstream and downstream flooding impacts;
e. 
Plans prepared by a licensed engineer for the structure or development in accordance with the hydraulic and hydrologic analysis required above;
f. 
Any other information requested by the director in order to demonstrate compliance with this chapter and ensure the development is reasonably safe from flooding.
3. 
Approval Criteria. Floodway development shall not result in any increase in flood levels during the occurrence of the base flood discharge. In addition, above-ground structures in the floodway shall be subject to the following:
a. 
The lowest horizontal element shall be three feet or more above the base flood elevation or the base flood elevation projected for the life of the development, whichever is greater;
b. 
The development shall not compromise flood protection improvements such as dikes and levees;
c. 
The structure shall allow for the unimpeded passage of floodwater and debris flows;
d. 
The structure shall be designed and constructed to minimize the number of vertical supports and fill placed in the floodway.
I. 
Alteration of Watercourses. Developments involving the alteration or relocation of a watercourse shall be subject to the following regulations:
1. 
The following documentation shall be provided with the flood development permit application:
a. 
A letter from FEMA stating that the proposed development does not require a conditional letter of map amendment; or
b. 
An approved conditional letter of map amendment.
2. 
If an approved conditional letter of map amendment is provided, any conditions, restrictions, or mitigation measures identified in the letter shall be included as conditions in the approved flood development permit.
3. 
Notification shall be provided to adjacent communities, the Washington State Department of Fish and Wildlife, the Washington State Department of Natural Resources, and the Washington State Department of Ecology prior to approving development, and shall submit evidence of such notification to FEMA.
4. 
Maintenance shall be provided within the portion of the watercourse that is altered or relocated so that the flood carrying capacity is not diminished. If the maintenance program does not call for cutting of native vegetation, the system shall be oversized at the time of construction to compensate for vegetation growth or any other natural factors that may necessitate future maintenance.
J. 
Development in the Special Flood Risk Zone. Development in the special flood risk zone shall be subject to the following regulations:
1. 
Development other than the following is prohibited in the special flood risk zone; provided, that nothing in this section shall be construed as authorizing construction or fill in wetlands:
a. 
Minor structures and additions for which a building permit is not required and which create no new residences;
b. 
Minor fills and excavations of less than 12 cubic yards or which will not raise the level of land above that of the surrounding area;
c. 
Normal maintenance, resurfacing and rebuilding at comparable grade of bridges, streets and access ways;
d. 
Underground improvements;
e. 
Maintenance, repair, alteration and like replacement of existing improvements;
f. 
Other minor development which causes no significant impoundment or displacement of floodwaters, such as signs and small unenclosed structures;
g. 
Elevated structures which allow floodwaters to flow underneath and which meet the following criteria:
i. 
All structures shall be elevated so that the lowest supporting member is located no lower than one foot above the 100-year flood elevation, with all space below the lowest supporting member open so as not to impede the flow of water, except for breakaway walls as provided below.
ii. 
Solid walls are prohibited below the base flood elevation to keep the area free of obstruction unless they are designed to break away. A breakaway wall shall have a design safe loading resistance of not less than 10 and no more than 20 pounds per square foot.
iii. 
All structures shall be securely anchored on piling, columns, or foundation walls oriented to the axis of the flow path. Said support elements shall be certified by a registered professional engineer or architect as capable of withstanding all applied loads of the 100-year flood flow.
iv. 
There shall be no fill used for structural support.
2. 
Regardless of method of construction, operation, development, substantial improvement, or expansion of residential health care facilities is prohibited in the special flood risk zone.
3. 
New multifamily residential structures are prohibited in the special flood risk zone.
4. 
Land divisions, including short plats, subdivisions, and binding site plans, shall be subject to the following:
a. 
No lot shall be created through a subdivision or short subdivision which lacks an adequate building site outside the floodway or special flood risk area, unless restrictive notes are included on the face of the plat permanently prohibiting development of the lot, or restricting the use of the lot to flood control structures and improvements; and
b. 
Land within a floodway or special flood risk zone shall be placed within a separate tract or easement if required by BMC § 14.15.200(B) and BMC Title 16.
5. 
New structures shall not be located within a special flood risk zone but yards and other nonstructural improvements that fully comply with all other applicable requirements identified in this chapter may extend into a special flood risk zone.
6. 
New structures shall be located so that the proposed project will not affect the hydrologic or hydraulic characteristics of a flooding source and must be certified by a registered professional engineer.
7. 
Proposed structures with an estimated value greater than $250,000 shall be subject to the following:
a. 
The proposed structure shall not have a significant adverse impact on flood hazards; and
b. 
There are no other physically feasible alternatives available.
8. 
Development for which a floodplain permit is required shall not be permitted riverward of a dike or levee or within 100 feet of the landward toe of a dike or levee except as follows:
a. 
Improvements to dikes, levees, and flood control improvements; and
b. 
Interim uses involving no fill, asphalt, stockpiling of material, or permanent structures; and
c. 
Utility outfall structures authorized by the Corps of Engineers; and
d. 
The construction and maintenance of dikes and levees for flood control purposes; and
e. 
Bridges and other river crossings for transportation or utility purposes as minimally necessary for purposes of permitting an essential public facility.
f. 
Prior to authorizing any development riverward of a dike or levee or within 100 feet of the landward toe of a dike or levee the city shall consult with the dike district and shall incorporate conditions as necessary to protect the structural integrity of dikes, levees, and other flood control improvements and as necessary to permit emergency flood fighting efforts.
(Ord. 1903 § 2 (Exh. A), 2021; Ord. 1933 § 1 (Exh. A), 2023)
A. 
General. The following development activities shall be subject to the floodplain construction standards in this section:
1. 
Construction or placement of a new structure;
2. 
Reconstruction, rehabilitation, or other improvements the meet the definition of a "substantial improvement";
3. 
Repairs to an existing building that has been substantially damaged;
4. 
Placing a manufactured home on a lot or site;
5. 
Placing a recreational vehicle or travel trailer on a lot or site for more than 180 days;
6. 
Additions to existing structures.
B. 
Residential Construction.
1. 
All new structures, additions, and substantial improvements shall have the lowest floor, including basement, elevated at or above the FPE.
2. 
The structure shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
3. 
All materials below the FPE shall be resistant to flood damage and firmly anchored to prevent flotation. Materials harmful to aquatic wildlife, such as creosote, are prohibited below the FPE.
4. 
Electrical, heating, ventilation, duct work, 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.
5. 
Fully enclosed areas below the lowest floor that are subject to flooding, including garages attached to residential structures where the floor slab is below the base flood elevation, 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 criteria below:
a. 
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.
b. 
The bottom of all openings shall be no higher than one foot 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.
6. 
In zones V, V1-30 and VE, new structures and substantial improvements shall be elevated on pilings or columns so that:
a. 
The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated above the FPE.
b. 
The pile or column foundation and structure attached thereto is anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Wind and water loading values shall each have a one percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval).
c. 
The areas below the lowest floor that are subject to flooding shall be free of obstruction.
d. 
The structure or improvement shall be located landward of the reach of mean high tide.
e. 
The use of fill for structural support of a structure or addition is prohibited.
f. 
A registered professional engineer or architect shall develop or review the structural design, specifications and plans for the construction, and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for meeting these provisions.
C. 
Nonresidential Construction.
1. 
The structure shall not located in zones V, V1-30, or VE;
2. 
New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall have the lowest floor, including basement, elevated at or above the flood protection elevation, or the elevation required by ASCE 24, whichever is greater. Mechanical equipment and utilities shall be waterproofed or be installed at or above the flood protection elevation or the elevation required by ASCE 24, whichever is greater;
3. 
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 criteria below:
a. 
A minimum of two openings with a total net area of at least 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 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;
4. 
As an alternative to the elevation and venting requirements identified in subsections (C)(2) and (3) of this section, new construction and substantial improvements may be dry floodproofed in accordance with the following standards:
a. 
All portions of the structure below the flood protection elevation, or the elevation required by ASCE 24, whichever is greater, shall be dry floodproofed with watertight walls substantially impermeable to the passage of water;
b. 
The structural components shall be capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
c. 
A registered professional engineer or licensed architect shall stamp the building plans and certify 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; and
d. 
A permit condition shall be included notifying the permit applicant that flood insurance premiums be determined based on an elevation that is one foot below the floodproofed elevation. For example, if the dry floodproofed elevation is one foot above the base flood elevation, flood insurance rates will be assessed as if the building is located at the base flood elevation; and
5. 
Mechanical equipment, HVAC systems, and utilities shall either be installed at or above the flood protection elevation, waterproofed, or located in an area that has been dry floodproofed in accordance with the requirements of this chapter.
D. 
Manufactured Homes. The placement of manufactured homes on a site or lot, substantial improvements to existing manufactured homes shall be subject to the following regulations:
1. 
A permanent foundation shall be provided; and
2. 
The foundation shall be elevated in accordance with the requirements of this section; and
3. 
The manufactured home shall be 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.
4. 
Only manufactured homes meeting the definition of a "manufactured home" in BMC Title 17 shall be used as a dwelling unit or a place of permanent habitation. Recreational vehicles shall not be used as a dwelling unit or a place of permanent habitation.
E. 
Crawlspaces. Buildings utilizing crawlspace construction, where any portion of the crawlspace is below the grade on all sides, shall meet the following requirements:
1. 
Crawlspace construction is not permitted in the V zones;
2. 
Crawlspace construction is not permitted in zones AO and A1-A30 where floodwater velocities could exceed five feet per second, unless it can be shown through an engineering analysis that the structural components will resist flotation, collapse, and lateral movement from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
3. 
The interior grade of the crawlspace shall not be more than two feet below the lowest adjacent grade;
4. 
The height of the crawlspace, measured from the interior grade of the crawlspace to the top of the foundation wall, shall not exceed four feet at any point and the height, measured from the crawlspace grade to the top of the next highest floor, shall not exceed five feet at any point;
5. 
An adequate drainage system shall be provided to remove floodwaters from the crawlspace in a reasonable amount of time after a flood event.
F. 
Accessory Structures. Accessory structures shall comply with all of the requirements in this section, except that accessory structures shall be exempt from elevation requirements provided they are:
1. 
Used only for parking or storage; and
2. 
Constructed and placed on the site or lot so as to offer minimum resistance to the flow of floodwaters; and
3. 
Anchored to prevent flotation which may result in damage to other structures; and
4. 
Constructed of flood-resistant materials below the flood protection elevation.
G. 
Certificate of Occupancy. No final inspection or occupancy shall be approved unless all of the following requirements have been met:
1. 
An elevation or floodproofing certificate, consistent with the requirements of this chapter, shall be submitted;
2. 
For projects subject to floodplain habitat mitigation plan requirements, all of the required mitigation activities and work identified in the mitigation plan shall be completed and inspected;
3. 
Copies of all other required federal, state, and local permits shall be submitted;
4. 
The project fully complies with the requirements of this chapter.
(Ord. 1903 § 2 (Exh. A), 2021; Ord. 1933 § 1 (Exh. A), 2023)
A. 
Applicability. A habitat assessment, and if necessary a mitigation plan, shall be provided with all applications for a flood development permit unless the development activity is explicitly identified as being exempt below.
B. 
Exempt Development. The following development activities shall be exempt from the habitat assessment and mitigation requirements of this section:
1. 
Repairing or remodeling an existing structure provided the work does not constitute a substantial improvement or a repair to substantial damage.
2. 
Additions to existing structures provided the addition or expansion does not increase the footprint of the structure by more than 10 percent, or constitute a substantial improvement. For purposes of determining compliance with this requirement, measurements shall be counted cumulatively from the effective date of the ordinance codified in this chapter or September 22, 2011, whichever is earlier. If the structure is in the floodway, there shall be no change in the dimensions perpendicular to flow.
3. 
Development undertaken for the sole purpose of creating, restoring or enhancing the natural functions of floodplains, streams, watercourses, fish and wildlife habitat, and riparian areas; provided, that:
a. 
The project complies with all other applicable federal, state, and local permit requirements and regulations;
b. 
The development activities do not include the placement of fill or the creation of additional impervious surface areas.
4. 
Development of open space and recreational facilities, such as parks, trails, and play fields, that do not include structures, fill, impervious surfaces or the removal of more than five percent of the native vegetation within the floodplain management area.
5. 
Other development activities consistent with all of the following:
a. 
Native vegetation within the riparian habitat zone shall not be removed; and
b. 
Native vegetation removal outside of the riparian habitat zone does not exceed 35 percent of the surface area of the portion of the site within the floodplain management area. If the site contains a riparian habitat zone, the vegetation within the riparian habitat zone may be counted towards this requirement; and
c. 
The development does not involve the storage, handling, processing, disposal, transport, or production of significant quantities of 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; and
d. 
The development is not riverward of a dike or levee; and
e. 
The development does not reduce the effective flood storage volume of the floodplain management area, or the development provides compensatory storage consistent with all of the following:
i. 
The compensatory storage is provided at an equivalent volume and at equivalent elevations to the flood storage capacity being displaced. For purposes of interpreting this requirement "equivalent elevation" shall mean an elevation with a similar relationship to the ordinary high water and the best available 15-, 50-, and 100-year flood surface water profiles; and
ii. 
The compensatory storage is hydraulically connected to the source of flooding; and
iii. 
Flood development permit applications for projects involving compensatory mitigation shall include grading plans and calculations prepared by a licensed engineer demonstrating compliance with the compensatory mitigation requirements.
C. 
Habitat Impact Assessment. Unless the proposal involves development activities explicitly identified above as exempt, all flood development permit applications shall include a habitat assessment prepared consistent with the requirements of this section.
1. 
Requirements. All habitat assessments shall include the following information, analysis, and materials:
a. 
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
b. 
Documentation that the activity fits within Section 4(d) of the Endangered Species Act; or
c. 
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
d. 
An assessment prepared in accordance with Regional Guidance for Floodplain Habitat Assessment and Mitigation, FEMA Region 10, 2010. The assessment shall determine if the project would adversely affect:
i. 
Species that are federal, state or local listed as threatened or endangered;
ii. 
The primary constituent elements for critical habitat, when designated;
iii. 
Essential fish habitat designated by the National Marine Fisheries Service;
iv. 
Fish and wildlife habitat conservation areas;
v. 
Other protected areas and elements necessary for species conservation.
D. 
Habitat Mitigation Plan. If the habitat assessment provided with the flood development permit application concludes the development is expected to have an adverse effect on water quality, aquatic or riparian habitat, or habitat functions, the applicant shall provide a habitat mitigation plan. The following requirements shall apply to habitat mitigation plans and to all developments requiring a habitat mitigation plan:
1. 
Habitat mitigation plans shall be prepared in accordance with standards and procedures identified in the "Regional Guidance for Floodplain Habitat Assessment and Mitigation" published by FEMA Region 10.
2. 
If the project is located outside the protected area, the mitigation plan shall include such avoidance, minimization, restoration, or compensation measures so that indirect adverse effects of development in the floodplain (effects to stormwater, riparian vegetation, bank stability, channel migration, hyporheic zones, wetlands, large woody debris, etc.) are mitigated such that equivalent or better habitat protection is provided.
3. 
New stream crossings are not allowed outside the protected area unless the crossing has been explicitly approved consistent with the requirements of this chapter.
4. 
For development within 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.
5. 
The plan's habitat mitigation activities shall be incorporated into the design of development. The floodplain development permit shall be based on the redesigned project and its mitigation components.
6. 
If the NMFS or USFWS issues an incidental take permit under Section 10 ESA, Biological Opinion under Section 7, ESA; it can be then it can be used as a mitigation plan to meet the requirements of this section.
(Ord. 1903 § 2 (Exh. A), 2021)
Certificates, forms, studies, and other documents required by this chapter shall be consistent with the following requirements and shall be maintained by the city and made available for public review:
A. 
The finished construction elevations required by this chapter shall be recorded on a current FEMA elevation certificate. All elevation certificates shall be prepared, stamped, and signed by a professional land surveyor licensed in the state of Washington.
B. 
Base flood elevation data, in relationship to the datum of the effective FIRM, shall be recorded on a current FEMA floodproofing certificate. All floodproofing certificates shall be prepared, stamped, and signed by a professional engineer licensed in the state of Washington.
C. 
Flood development permits, documents included with flood development permit applications, elevation certificates, floodproofing certificates, and certificates of occupancy shall be maintained by the city and shall be available for public review.
D. 
Maps, studies, reports and other sources of information used in the administration of this section shall be maintained by the director and shall be available for public review.
E. 
The city shall maintain, and make available for public review, any other documents or studies required by this chapter including, but not limited to, floodplain habitat assessments, improvement and damage calculations, inspection records, approved permits, and completed application forms.
(Ord. 1903 § 2 (Exh. A), 2021)
Failure to obtain a flood development permit or any other violation of any of the regulations identified in this section shall be subject to the penalty and enforcement provisions identified in chapter 1.34 BMC and any other applicable enforcement provisions authorized by Burlington Municipal Code.
(Ord. 1903 § 2 (Exh. A), 2021)