Chapter 4.10E
CRITICAL AREA REGULATIONS FREQUENTLY FLOODED AREAS
Sections:
4.10E.010 Statutory authorization.
4.10E.030 Statement of purpose.
4.10E.040 Methods of reducing flood losses.
4.10E.060 Lands to which this chapter applies.
4.10E.070 Basis for establishing the areas of special flood hazard.
4.10E.110 Warning and disclaimer of liability.
4.10E.120 Establishment of development permit.
4.10E.130 Designation of the mayor.
4.10E.140 Duties and responsibilities of the mayor.
4.10E.210 Standards for shallow flooding areas (AO zones).
4.10E.010 Statutory authorization.
The legislature of the state has delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the city council ordains as set forth in this chapter. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.020 Findings of fact.
A. The flood hazard areas identified by the FEMA maps and study adopted in this chapter are subject to periodic inundation which results in loss of life and property, health, and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety, and general welfare.
B. These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities, and when inadequately anchored, damage uses in other areas. Uses that are inadequately floodproofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.030 Statement of purpose.
It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed:
A. To protect human life and health;
B. To limit expenditure of public money on costly flood control projects;
C. To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
D. To minimize prolonged business interruptions;
E. To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets, and bridges located in areas of special flood hazard;
F. To help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future flood blight areas;
G. To ensure that potential buyers are notified that property is in an area of special flood hazard; and
H. To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.040 Methods of reducing flood losses.
In order to accomplish its purposes, this chapter includes methods and provisions for:
A. Restricting or prohibiting uses which are dangerous to health, safety, and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;
B. Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
C. Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel floodwaters;
D. Controlling filling, grading, and other development which may increase flood damage; and
E. Preventing or regulating the construction of flood barriers that will unnaturally divert floodwaters or may increase flood hazards in other areas. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.050 Definitions.
Unless specifically defined below, words or phrases used in this chapter shall be interpreted so as to give them the meaning they have in common usage and to give this chapter its most reasonable application:
“Appeal” means a request for a review of the city’s interpretation of any provision of this chapter or a request for a variance.
“Area of shallow flooding” means designated AO or AH zone on the flood insurance rate map (FIRM). The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident. AO is characterized as sheet flow and AH indicates ponding.
“Area of special flood hazard” means the land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year. Designation on maps always includes the letter A or V.
“Critical facility” means a facility for which even a slight chance of flooding might be too great. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and emergency response installations, installations which produce, use, or store hazardous materials or hazardous waste.
“Development” means any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations located within the area of special flood hazard.
“Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from:
1. The overflow of inland or tidal waters; and/or
2. The unusual and rapid accumulation of runoff of surface waters from any source.
“Flood insurance rate map (FIRM)” means the official report provided by the Federal Insurance Administration that includes flood profiles, the flood boundary-floodway map, and the water surface elevation of the base flood.
“Floodway” means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevations more than one foot.
“Lowest floor” means the lowest floor of the lowest enclosed area (including basement). An unfinished or flood-resistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building’s lowest floor; provided, that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of this chapter found at Section 4.10E.180(A)(2).
“Manufactured home” means a structure constructed after June 15, 1976, and in accordance with state and federal requirements for manufactured homes. All manufactured homes shall bear the appropriate insignia by a state or federal regulatory agency indicating such compliance with all applicable construction standards of the U.S. Department of Housing and Urban Development for manufactured homes as adopted by the Washington State Department of Labor and Industries or the International Building Code as adopted by the city of Bridgeport and be designed primarily for residential occupancy by human beings. For floodplain management purposes the term “manufactured home” also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than forty consecutive days. For insurance purposes the term “manufactured home” does not include park trailers, travel trailers, or other similar vehicles.
“Manufactured home park or subdivision” means a parcel of land under single ownership used for or available for rent for the placement of two or more manufactured homes used as dwellings and meeting the certification requirements of this title. For the purposes of this title the term “manufactured home park” shall be synonymous with the term “mobile home park,” as defined herein, and shall be allowed in any district where mobile home parks are allowed. All mobile home parks proposed or expanded under this title must meet the standards for a manufactured home park.
“New construction” means a structure for which the “start of construction” commenced on or after the effective date of the ordinance codified in this chapter.
“Start of construction” includes substantial improvement, and means the date the building permit was issued provided the actual start of construction, repair, reconstruction, placement or other improvement was within forty days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundation or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure.
“Structure” means a walled and roofed building including a gas or liquid storage tank that is principally above ground.
“Substantial improvement” means any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds fifty percent of the market value of the structure either:
1. Before the improvement or repair is started; or
2. If the structure has been damaged and is being restored, before the damage occurred. For the purposes of this definition “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.
3. The term does not, however, include either:
a. Any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions; or
b. Any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.
“Variance” means the grant of relief from the requirements of this chapter that permits construction in a manner that would otherwise be prohibited by this chapter.
“Water dependent” means a structure for commerce or industry that cannot exist in any other location and is dependent on the water by reason of the intrinsic nature of its operation. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.060 Lands to which this chapter applies.
This chapter shall apply to all areas of special flood hazards within the jurisdiction of the city. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.070 Basis for establishing the areas of special flood hazard.
The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for the City of Bridgeport” dated, November 17, 1981, with accompanying flood insurance maps is adopted by reference and declared to be a part of this chapter. The flood insurance study is on file at City Hall, 1206 Columbia Avenue, Bridgeport, Washington. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.100 Interpretation.
In the interpretation and application of this chapter, all provisions shall be:
A. Considered as minimum requirements;
B. Liberally construed in favor of the governing body; and
C. Deemed neither to limit nor repeal any other powers granted under state statutes.
Potential impacts to wetlands, fish and wildlife habitat and other critical areas shall be addressed in accordance with the applicable sections of this chapter. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.110 Warning and disclaimer of liability.
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by man-made or natural causes. This chapter does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the city, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.120 Establishment of development permit.
A. Development Permit Required. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in this section. The permit shall be for all structures including manufactured homes, as set forth in Section 4.10E.050, and for all development including fill and other activities, also as set forth in Section 4.10E.050.
B. Applications 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, locations, dimensions, and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing. Specifically, the following information is required:
1. Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;
2. Elevation in relation to mean sea level to which any structure has been floodproofed;
3. Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in Section 4.10E.040(B); and
4. Description of the extent to which a watercourse will be altered or relocated as a result of the proposed development. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.130 Designation of the mayor.
The mayor or his/her designee is appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.140 Duties and responsibilities of the mayor.
Duties of the mayor shall include, but not be limited to:
A. Review all development permits to determine:
1. That the permit requirements of this chapter have been satisfied;
2. That all necessary permits have been obtained from those federal, state, or local governmental agencies from which prior approval is required;
3. If the proposed development is located in the floodway. If located in the floodway, assure that the provisions of Section 4.10E.190 are met.
B. When base flood elevation data has not been provided in accordance with Section 4.10E.070, the mayor shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer Sections 4.10E.040 and 4.10E.190.
C. Obtain and maintain the following information:
1. Where base flood elevation data is provided through the flood insurance study or required as in subsection (B) of this section, obtain and record the actual (as built) elevation (in relation to mean sea level) of the lowest floor, including basement, of all new or substantially improved structures, and whether or not the structure contains a basement.
2. For all new or substantially improved floodproofed structures:
a. Obtain and record the actual elevation (in relation to mean sea level) to which the structure was floodproofed; and
b. Maintain the floodproofing certifications required in Section 4.10E.120(B)(3).
3. Maintain for public inspection all records pertaining to the provisions of this chapter.
D. Where there are proposed alteration(s) of watercourses, accomplish the following:
1. 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.
2. Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood-carrying capacity is not diminished.
E. Make interpretations where needed, as to exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). A person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Title 19 BMC for administrative appeals. In passing upon such applications, the hearing officer shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and:
1. The danger that materials may be swept onto other lands to the injury of others;
2. The danger to life and property due to flooding or erosion damage;
3. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;
4. The importance of the services provided by the proposed facility to the community;
5. The necessity to the facility of a waterfront location, where applicable;
6. The availability of alternative locations for the proposed use which is not subject to flooding or erosion damage;
7. The compatibility of the proposed use with existing and anticipated development;
8. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;
9. The safety of access to the property in times of flood for ordinary and emergency vehicles;
10. 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
11. 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.
F. The mayor shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. (Ord. 707 § 1, 2020; Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.160 Variances.
A. Variances, as interpreted in the National Flood Insurance Program, are based on the general zoning law principle that they pertain to a physical piece of property; they are not personal in nature and do not pertain to the structure, its inhabitants, economic or financial circumstances. They primarily address small lots in densely populated residential neighborhoods. As such, variances from the flood elevations should be quite rare.
B. Variances may be issued for the reconstruction, rehabilitation, or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places, without regard to the procedures set forth in this section.
C. Variances shall not be issued within a designated floodway if any increase in flood levels during the base flood discharge would result.
D. Generally, the only condition under which a variance from the elevation standard may be issued is for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing Section 4.10E.140(E)(1) through (11) have been fully considered. As the lot size increases the technical justification required for issuing the variance increases.
E. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
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 except subsection (A) of this section, and otherwise complies with Section 4.10E.170(A) and (B).
G. Variances shall only be issued upon:
1. A showing of good and sufficient cause;
2. A determination that failure to grant the variance would result in exceptional hardship to the applicant;
3. 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 as identified in Section 4.10E.140, or conflict with existing local laws or ordinances.
H. Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.170 General standards.
In all areas of special flood hazards, the following standards are required:
A. Anchoring.
1. All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure;
2. 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).
B. Construction Materials and Methods.
1. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage;
2. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage;
3. Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
C. Utilities.
1. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system;
2. 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
3. On-site waste disposal systems, where permitted, shall be located to avoid impairment to them or contamination from them during flooding.
D. 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 flood damage;
3. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage;
4. All subdivisions shall disclose the presence on each residential lot of one building site, including access, that is suitable of development and is not within the area of special flood hazard; and
5. 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 lots or five acres (whichever is less). (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.180 Specific standards.
In all areas of special flood hazards where base flood elevation data has been provided as set forth in Section 4.10E.070 or 4.10E.140(B), the following provisions are required:
A. Residential Construction.
1. New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated one foot or more above base flood elevation.
2. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of 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:
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.
B. Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated one foot or more above the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:
1. Be floodproofed so that below one foot above the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
2. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
3. 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 as set forth in Section 4.10E.140(C)(2);
4. Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection (A)(2) of this section;
5. Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (e.g., a building floodproofed to one foot above the base flood level will be rated as at the base flood level).
C. 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 or more above the base flood elevation; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of Section 4.10E.170(A)(2).
D. Where elevation data is not available either through the flood insurance study, FIRM, or from another authoritative source (Section 4.10E.140(B)), 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.
E. Recreational vehicles placed on sites are required to either:
1. Be on the site for fewer than one hundred eighty consecutive days; or
2. Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or
3. Meet the requirements of subsection (C) of this section and the elevation and anchoring requirements for manufactured homes. (Ord. 707 §§ 2—4, 2020; Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.190 Floodways.
Located within areas of special flood hazard established in Section 4.10E.070 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:
A. Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer or architect is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood damage.
B. Construction or reconstruction of residential structures is prohibited within designated floodways, except for: (1) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and (2) repairs, reconstruction or improvements to a structure, the cost of which does not exceed fifty percent of the market value of the structure, either: (a) before the repair, reconstruction, or repair is started, or (b) if the structure has been damaged, and is being restored, before the damage occurred. Work done on structures to comply with existing health, sanitary, or safety codes or to structures identified as historic places shall not be included in the fifty percent.
C. If subsection (A) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this article.
D. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the special flood hazard area (SFHA) (one-hundred-year floodplain). Construction of new critical facilities shall be permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated three feet above BFE or to the height of the five-hundred-year flood, whichever is higher. Access to and from the critical facility should also be protected to the height utilized above. 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 extent possible. (Ord. 707 § 5, 2020; Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.200 Encroachments.
The cumulative effect of any proposed development, where combined with all other existing and anticipated development, shall not increase the water surface elevation of the base flood more than one foot at any point. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)
4.10E.210 Standards for shallow flooding areas (AO zones).
Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these zones range from one to three feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. In these areas, the following provisions apply:
A. New construction and substantial improvements of residential structures within AO zones shall have the lowest floor (including basement) elevated above the highest grade adjacent to the building, one foot or more above the depth number specified on the FIRM (at least two feet if no depth number is specified).
B. New construction and substantial improvements of nonresidential structures within AO zones shall either:
1. Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, one foot or more above the depth number specified on the FIRM (at least two feet if no depth number is specified); or
2. Together with attendant utility and sanitary facilities, be completely floodproofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect as in Section 4.10E.180(B)(3).
C. Require adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures. (Ord. 675 § 1 (Exh. A) (part), 2017: Ord. 562 § 1 (part), 2006)