15.56.150 Provisions for flood hazard reduction--Standards of construction.

   In all areas of special flood hazards the following standards are required:

   A.   Anchoring.

      1.   All new construction and substantial improvements shall be adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

      2.   All manufactured homes shall meet the anchoring standards of Section 15.56.180.

   B.   Construction Materials and Methods.

      1.   All new construction and substantial improvement shall be constructed with materials and utility equipment resistant to flood damage.

      2.   All new construction and substantial improvement shall be constructed using methods and practices that minimize flood damage.

      3.   All new construction and substantial improvement shall 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.

      4.   Require within Zones AH or AO that adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures.

   C.   Elevation and Floodproofing.

      1.   New construction and substantial improvement shall have the lowest floor, including basement, elevated a minimum one foot above the base flood elevation (i.e. finish floor elevation one foot above base flood elevation). Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, or verified by the city building inspector to be properly elevated. Such certification or verification shall be provided to the floodplain administrator.

      2.   New construction and substantial improvement in Zone AO shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as a minimum one foot above the depth number specified in feet on the FIRM, or at least two feet if no depth number is specified. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, or verified by the building inspector to be properly elevated. Such certification or verification shall be provided to the floodplain administrator.

      3.   Nonresidential construction shall either be elevated to conform to subsection (C)(1) or (C)(2) of this section or together with attendant utility and sanitary facilities:

         a.   Be floodproofed so that below 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; and

         c.   Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifications shall be provided to the floodplain administrator.

      4.   Require, for all new construction and substantial improvement that fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria:

         a.   Either 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. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwater; or

         b.   Be certified to comply with a local floodproofing standard approved by the Federal Insurance Administration, Federal Emergency Management Agency.

      5.   Manufactured homes shall also meet the standards in Section 15.56.180.

(Ord. 424-09 § 5, 2009; Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.190)

15.56.160 Provisions for flood hazard reduction--Standards for utilities.

   A.   All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from systems into flood waters.

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

   C.   Other utilities are addressed at Sections 15.56.150(B) and 15.56.170(D).

(Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.200)

15.56.170 Provisions for flood hazard reduction--Standards for subdivisions.

   A.   All preliminary subdivision proposals shall identify the flood hazard area and the elevation of the base flood.

   B.   All subdivision plans will provide the elevation of proposed structure(s) and pad(s). If the site is filled above the base flood elevation, the final first floor and pad elevations shall be certified by a registered professional engineer or surveyor and provided to the floodplain administrator.

   C.   All subdivision proposals shall be consistent with the need to minimize flood damage.

   D.   All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.

   E.   All subdivisions shall provide adequate drainage to reduce exposure to flood hazards.

(Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.210)

15.56.180 Provisions for flood hazard reduction--Standards for manufactured homes.

   A.   All manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the city's flood insurance rate map on sites (1) outside of a manufactured home park or subdivision, (2) in a new manufactured home park or subdivision, (3) in an expansion to an existing manufactured home park or subdivision, (4) in an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood:

   Be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation collapse and lateral movement.

   B.   All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1-30, AH and AE on the community's flood insurance rate map that are not subject to the provisions of subsection A of this section shall be elevated so that either:

      1.   The lowest floor of the manufactured home is at or a minimum one foot above the base flood elevation, or

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

(Ord. 424-09 § 6, 2009; Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.220)

15.56.190 Provisions for flood hazard reduction--Standards for recreational vehicles.

   A.   All recreational vehicles placed on sites within Zones 2A1-3, AH, and AE on the city's flood insurance rate map will either:

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

      2.   Be fully licensed and ready for highway use (a recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnection type utilities and security services, and has no permanently attached additions), or

      3.   Meet the permit requirements of Section 15.56.120 of this chapter and the elevation and anchoring requirements for manufactured homes in Section 15.56.180(A).

(Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.230)

15.56.200 Provisions for flood hazard reduction--Floodways.

   Located within areas of special flood hazard established in Section 15.56.070. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and erosion potential, the following provisions apply:

   A.   Prohibit encroachments, including fill, new construction, substantial improvement, and other new 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 discharge.

   B.   If subsection A of this section is satisfied, all new construction, substantial improvement and other proposed new development shall comply with all other applicable flood hazard reduction provisions of Sections 15.56.150 through 15.56.220.

(Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.240)

15.56.210 Provisions for flood hazard reduction--Mudslide (i.e., mudflow)-prone areas.

   A.   The floodplain administrator shall review permits for proposed construction of other development to determine if it is proposed within a mudslide area.

   B.   Permits shall be reviewed to determine that the proposed development is reasonably safe from mudslide hazards. Factors to be considered in making this determination include but are not limited to:

      1.   The type and quality of soils;

      2.   Evidence of groundwater or surface water problems;

      3.   The depth and quality of any fill;

      4.   The overall slope of the site; and

      5.   The weight that any proposed development will impose on the slope.

   C.   Within areas which have mudslide hazards, the following requirements apply:

      1.   A site investigation and further review shall be made by persons qualified in geology and soils engineering;

      2.   The proposed grading, excavating, new construction, and substantial improvement shall be adequately designed and protected against mudslide damages;

      3.   The proposed grading, excavations, new construction and substantial improvement shall not aggravate the existing hazard by creating either on-site or off-site disturbances; and

      4.   Drainage, planting, watering and maintenance shall not endanger slope stability.

   D.   Within Zone M on the flood insurance rate map, the city shall adopt a drainage ordinance which at least complies with the standards of Sections 7001 through 7006 and Sections 7008 through 7015 of the 1988 Uniform Building Code:

      1.   The location of foundation and utility systems of new construction, substantial improvement and other proposed development;

      2.   The location, drainage and maintenance of all excavations, cuts and fills and planted slopes;

      3.   Protective measures including but not limited to retaining walls, buttress fills, subdrains, diverter terraces, benchings, etc.; and

      4.   Engineering drawings and specifications to be submitted for all corrective measures, accompanied by supporting soils engineering and geology reports.

(Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.260)

15.56.220 Provisions for flood hazard reduction--Flood-related erosion-prone areas.

   A.   The floodplain administrator shall require permits for proposed construction and other development within all flood-related erosion-prone areas known to the city.

   B.   Such permits shall be reviewed to determine whether the proposed site alterations and improvements will be reasonably safe from flood-related erosion and will not cause flood-related erosion hazards or otherwise aggravate the existing hazard.

   C.   If a proposed improvement is found to be in the path of flood-related erosion or would increase the erosion hazard, such improvement shall be relocated or adequate protective measures shall be taken to avoid aggravating the existing erosion hazard.

   D.   Within Zone E of the flood insurance rate map, a setback is required for all new development from the ocean, lake, bay, riverfront, or other body of water to create a safety buffer consisting of a natural vegetative or contour strip. This buffer shall be designated according to the flood-related erosion hazard and erosion rate, in relation to the anticipated "useful life" of structures, and depending upon the geologic, hydrologic, topographic and climatic characteristics of the land. The buffer may be used for suitable open space purposes, such as for agricultural, forestry, outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only.

(Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.270)