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 SJBMC 12-1-415.
(B) 
Construction Materials and Methods. All new construction and substantial improvement shall be constructed as follows:
(1) 
With materials and utility equipment resistant to flood damage;
(2) 
Using methods and practices that minimize flood damage;
(3) 
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; and
(4) 
Within Zones AH or AO, so that there are adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed or existing structures.
(C) 
Elevation and Floodproofing.
(1) 
Residential construction, new or substantial improvement, shall have the lowest floor, including basement, as follows:
(a) 
In an AO zone, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at least two feet (2') above the highest adjacent grade if no depth number is specified. (The State of California recommends that the lowest floor be elevated above the highest adjacent grade to a height exceeding the depth number specified in feet on the FIRM by at least one foot (1′), or elevated at least three feet (3') above the highest adjacent grade if no depth number is specified.)
(b) 
In an A Zone, elevated to or above the base flood elevation, as determined by the Flood-plain Administrator based on an engineering study done to determine the height of a base flood elevation for the property in question.
(c) 
In all other zones, elevated to or above the base flood elevation.
Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, and verified by the community building inspector to be properly elevated. Such certification or verification shall be provided to the Flood-plain Administrator.
(2) 
Nonresidential construction shall either be elevated to conform with SJBMC 12-1-400(C)(1) or, together with attendant utility and sanitary facilities, as follows:
(a) 
Be floodproofed below the elevation recommended under SJBMC 12-1-400(C)(1) so that 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.
(3) 
All new construction and substantial improvement with fully enclosed areas below the lowest floor (excluding basements) that are usable solely for parking of vehicles, building access or storage, 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 exceed the following minimum criteria:
(a) 
Be certified by a registered professional engineer or architect; or
(b) 
Be certified to comply with a local floodproofing standard approved by the Federal Insurance Administration, Federal Emergency Management Agency; or
(c) 
Have a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one foot (1′) 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.
(4) 
Manufactured homes shall also meet the standards in SJBMC 12-1-415.
(A) 
All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate:
(1) 
Infiltration of floodwaters into the systems; and
(2) 
Discharge from systems into floodwaters.
(B) 
On-site waste disposal systems shall be located to avoid impairment to them, or contamination from them during flooding.
(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 lowest 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.
(A) 
All manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the community’s Flood Insurance Rate Map on sites located outside of a manufactured home park or subdivision, or in a new manufactured home park or subdivision, or in an expansion to an existing manufactured home park or subdivision, or in an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred “substantial damage” as the result of a flood, shall 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 will be elevated so that either:
(1) 
The lowest floor of the manufactured home is at or 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 inches (36″) in height above grade and is securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
All recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community’s Flood Insurance Rate Map must either:
(A) 
Be on the site for fewer than one hundred eighty (180) consecutive days;
(B) 
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-disconnect type utilities and security devices, and has no permanently attached addition; or
(C) 
Meet the permit requirements of Article 3 of this Chapter and the elevation and anchoring requirements for manufactured homes in SJBMC 12-1-415(A).
Located within areas of special flood hazard established in SJBMC 12-1-205 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) 
All encroachments, including fill, new construction, substantial improvement, and other new development is prohibited in a floodway unless certification by a registered professional engineer or architect is provided demonstrating that encroachments shall not result in any increase in the base flood elevations 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 in a floodway shall comply with all other applicable flood hazard reduction provisions of Article 4 of this Chapter.
(C) 
All development or land disturbance shall be set back a minimum of fifty feet (50′) from the annual high water mark of San Juan Creek and twenty-five feet (25′) from the annual high water mark of the San Juan Tributary. Property owners may request a reduction in setback requirements as part of their development permit application. Any reduction in required setbacks may only be granted by the Planning Commission through the variance and a use permit process.
(A) 
The Floodplain Administrator shall review permits for proposed construction of development to determine if it is proposed within a mudslide area.
(B) 
Permits shall be reviewed to determine that the proposed site and improvement is reasonably safe from mudslide hazards. Factors to be considered in making this determination include but are not limited to:
(1) 
Type and quality of soils;
(2) 
Evidence of ground water or surface water problems;
(3) 
Depth and quality of any fill;
(4) 
Overall slope of the site; and
(5) 
Weight that any proposed development will impose on the slope.
(C) 
Within areas which have mudslide hazards, the Floodplain Administrator shall require that:
(1) 
A site investigation and further review be made by a registered geologist;
(2) 
The proposed grading, excavation, new construction, and substantial improvement be adequately designed and protected against mudslide damages;
(3) 
The proposed grading, excavations, new construction and substantial improvement not aggravate the existing hazard by creating either on-site or off-site disturbances; and
(4) 
Drainage, planting, watering and maintenance not endanger slope stability.
(D) 
Within those areas delineated as mudslide prone regions on the City’s environmental hazards map, all proposals for development within these regions shall submit the following information as part of their application for a development permit:
(1) 
The location of foundation and utility systems of new construction, substantial improvement and other proposed new 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, and benchings; and
(4) 
Engineering drawings and specifications to be submitted for all corrective measures, accompanied by supporting soils engineering and geology reports prepared by registered geologists and or geotechnical engineers.