Chapter 9.18 — FLOODPLAIN SAFETY OVERLAY DISTRICT

The floodplain safety (FP) overlay established by section 9.05.030, "Establishment Of Base Zoning And Overlay Districts", and chapter 9.15, "Overlay Districts", of this article 2, is created to provide greater public safety, promote public health, and minimize public and private economic losses due to flood conditions by establishing regulations for development and construction within flood prone areas. (Ord. 253, 12-16-2014)

A. The FP1, FP2, and FP3 overlays described in section 9.18.040 of this chapter are applied to areas of special flood hazard identified by the federal emergency management agency (FEMA) or the federal insurance administration in a scientific and engineering report entitled "Flood Insurance Study" for the county of San Bernardino, prepared in 1996, which has subsequent updates, with accompanying flood insurance rate maps (FIRMs). Subsequent report and map updates that may be published in the future shall further identify additional flood hazard areas.

B. The flood insurance study establishes the minimum areas to which the FP overlays may be applied. Additional areas may be added after studies for the areas are prepared by the flood control district or other governmental agencies (e.g., corps of engineers). (Ord. 253, 12-16-2014)

No structure or land use shall hereafter be constructed, located, extended, converted, or altered without full compliance with the provisions of this chapter and other applicable regulations. Violations of the provisions of this chapter by failure to comply with any of its requirements (including violation of conditions and safeguards required by conditions of approval) shall be subject to the penalties established by this development code. Nothing in this chapter shall prevent the town from taking lawful action as is necessary to prevent or remedy any violation.

A. Abrogation And Greater Restrictions: The provisions of this section are not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this section and another section, easement, covenant, or deed restriction conflict or overlap, the more stringent regulations or standards shall govern. B. Interpretation: In the interpretation and application of this section all provisions shall be considered as minimum requirements, liberally construed in favor of the governing body and, deemed neither to limit nor repeal any other powers granted under state statutes.

C. Implementation: The requirements of this section shall be integrated into the processing and review of all land use applications and development permits where specific flood hazard review and flood protection recommendations are necessary. (Ord. 253, 12-16-2014)

The floodplain safety overlay (FP) shall be subdivided into three (3) review areas as follows. Proposed development shall comply with the following standards of the applicable review area:

A. Floodplain review area 1 (FP1): FP1 includes areas subject to a base flood (also called 100-year flood) as defined by the federal flood insurance regulations. The following FEMA designated flood hazard zones are included in FP1: A and AE. The following standards shall apply to property within the FP1 area:

1. Elevation Of Lowest Floor: New construction and substantial improvement of any structure shall be constructed so that the first floor (including basement) shall be one foot (1') or more above the base flood elevation, when the FEMA map base flood elevations are shown, and will not result in any significant increase in flood levels during the base flood discharge. When the base flood elevations are not shown, new construction and substantial improvement of any residential structure shall be constructed so that the first floor (including basement) shall be two feet (2') or more above the highest adjacent grade.

2. Review Procedures: A project proposed in this area shall be subject to a flood hazard development review. This review shall ensure that the proposed project complies with this development code regarding flood protection measures and will require the submittal of an elevation certificate completed by a land surveyor, engineer, or architect who is authorized by state or local law to certify elevation information.

3. Development Restriction: In areas where no regulatory floodway has been designated, no new construction, substantial improvement or other development (including fill) shall be permitted within any areas designated by FEMA as A or AE on the FIRM or flood boundary maps, unless it is demonstrated that the cumulative effect of the proposed development when combined with all other existing and anticipated development will not increase the water surface elevation of the base flood more than one foot (1') at any point within the community.

B. Floodplain review area 2 (FP2): FP2 includes areas between limits of the base flood (100-year flood) and subject to a 500-year flood; and certain areas subject to 100-year flooding with an average depth of less than one foot (1') or where the contributing drainage areas are less than one square mile; or areas protected by levees from the base flood. The following FEMA designated flood hazard zones are included in FP2: shaded zone X. The following standards shall apply to property within the FP2 area:

1. Elevation Of First Floor: New construction and substantial improvement of any structure is recommended to be constructed so the first floor (including basement) shall be one foot (1') above the highest adjacent grade.

2. Review Procedures: A project proposed in this area may be subject to a flood hazard development review based upon the determination by the drainage section of land development of the town. This review shall ensure that the proposed project complies with this development code regarding flood protection measures and will require the submittal of an elevation certificate completed by a land surveyor, engineer, or architect who is authorized by state or local law to certify elevation information.

C. Floodplain review area 3 (FP3): FP3 includes areas of shallow flooding with undetermined (D) as defined on the FIRM map, but possible, flood hazards as determined by the town. The following standards shall apply to property within the FP3 area:

1. Field Investigation Required: Before a building permit can be issued on any affected lot, a field investigation shall be made of the lot to determine if the proposed construction will have any substantial detrimental effect on the drainageway. An applicant for the building permit on an affected lot shall first apply for the required field investigation and shall pay the appropriate fee. The following shall be included in the application for field investigation:

a. A plot plan showing the proposed structures and grading by size, location and orientation.

2. Final Building Plan Content: The final building plans that are submitted for approval shall show the approved location and mitigating measures. (Ord. 253, 12-16-2014)

A. Standards Of Construction: The following provisions shall apply in all areas of special flood hazards:

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

the effects of buoyancy. If a structure is elevated on fill as specified in subsections A2e and A3a of this section, the anchoring requirement shall be satisfied. Other alternative anchoring techniques that are effective may be considered.

2. Construction Materials And Methods:

a. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. This would include, but not be limited to, water resistant lumber, floor coverings, adhesives, paints, masonry construction and finishes, waterproof electrical systems, and mechanical footings, or other acceptable materials measures. (See FEMA technical bulletin TB 2-93.)

b. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage. This would include, but not be limited to, elevating the structure, parallel alignment of structure with water flow, increase the structural designs to withstand hydrologic and hydrolographic sources, and increase depth of footings.

c. All new construction and substantial improvements 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.

d. Adequate drainage paths are provided around structures on slopes to guide floodwaters around and away from proposed structures.

e. If fill is placed to elevate pads one foot (1') above base elevation, it must be demonstrated that fill will not settle and is protected from erosion, scour, or differential settlement, as follows:

(1) Fill shall be compacted to ninety five percent (95%) per ASTM (American Society For Testing And Materials) standard D-698.

(2) Fill slopes of granular material shall be no steeper than one-half foot ([1] /2') horizontal to one foot (1')

vertical ratio unless substantiating data for steeper slopes is provided, and the slopes are approved by the town. (3) If flow velocities are greater than five feet (5') per second, fill slopes shall be armored with stone or rock slope protection.

3. Elevation And Floodproofing:

a. New construction and substantial improvement of any residential structure shall include having the lowest floor (including basement), elevated to one foot (1') above base flood elevation or two feet (2') or more above the highest adjacent grade in the FP1 area, and it is recommended in the FP2 area to be one foot (1') above ground level. Upon completion of the structure, the elevation of the lowest floor (including basement) shall be certified by a registered professional engineer or licensed land surveyor, and verified by the building official to be properly elevated above the floodplain elevation at the time of certification. The certification or verification shall be provided to the floodplain administrator. In instances when the base flood elevation data has not been provided on the flood insurance rate map (FIRM), the provisions of this development code shall apply.

b. Nonresidential construction shall be either elevated in compliance with subsection A3a of this section or together with attendant utility and sanitary facilities and shall:

(1) Be floodproofed so that below 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; and

(3) 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 management administrator.

c. All new construction and substantial improvements to existing structures, shall include fully enclosed structural areas below the lowest floor that are subject to flooding, and the areas 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:

• (1) Be certified by a registered professional engineer or an architect; or

• (2) Provide a minimum of two (2) openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. 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 floodwaters; or

• (3) Be verified by the floodplain administrator as complying with floodproofing standards approved by the federal insurance administration.

• B. Utility Standards:

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

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

3. All public utilities and facilities such as electrical, telephone, cable TV, gas, etc., shall utilize floodproofing measures in their location and construction to minimize flood damage.

• C. Zoning Application Review Requirements:

1. All preliminary proposals shall identify the special flood hazard area and the elevation of the base flood.

2. All final plans shall provide the elevation of proposed structures and pads above the floodplain elevation as derived from the FEMA map adopted at the time of certification. If the site is filled above the base flood, the final pad elevation shall be certified by a registered professional engineer or licensed land surveyor and shall be submitted to the floodplain management administrator. The entire site need not be elevated; only the building pads need be elevated and other means of conducting storm flows through the site shall be provided.

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

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

5. All proposals shall provide adequate drainage to reduce exposure to flood hazards and not deflect flood flows onto other properties.

• D. Manufactured Homes: All new and replacement manufactured homes and additions to manufactured homes shall comply with all applicable provisions of this section.

1. Nonresidential construction shall be elevated in compliance with subsection A3 of this section.

2. All manufactured homes shall be securely anchored to a permanent foundation system to resist flotation, collapse or lateral movement. Methods of anchoring shall include, but not be limited to, the use of over the top or frame ties to ground anchors.

• E. Floodway Standards: Floodways are extremely hazardous areas due to the velocity of floodwaters that carry debris, potential projectiles, and erosion potential, therefore, the following provisions apply:

1. Encroachments, including fill, new construction, substantial improvements, stockpiling, and other development are prohibited 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.

2. If subsection E1 of this section is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions of this section. (Ord. 253, 12-16-2014)

A. Exceptions: The following structures and land uses are exempt from the requirements and standards established by this chapter:

1. Existing legally constructed structures for human habitation within the floodplain safety overlay shall be considered legal nonconforming uses and subject to the privileges and regulations thereof.

2. Structures for human habitation for which there was a valid building permit in effect at the time this section became effective.

3. The reconstruction, rehabilitation or restoration of structures listed on the national register of historic places or a state inventory of historic places.

4. Replacement of utilities, including septic systems, in compliance with health and safety codes shall be exempt from the flood elevation requirements of this development code and shall otherwise be subject to the legal nonconforming use provisions of this development code.

B. Modifications: In the public interest, the director may, without notice or public hearing, approve, conditionally approve, deny or refer to the commission requests to modify the requirements of the floodplain safety (FP) overlay.

1. Procedure: Written application (variance) for such modifications shall be submitted to the planning division, upon the forms provided by the town for this purpose.

2. Required Findings: A modification to the standards imposed by this chapter shall be allowed subject to lawful conditions that will secure substantial protection for the public health, safety and general welfare and provided that all of the following be found and justified as being true:

a. The modification, if within any designated regulatory floodway, will not result in any significant increase in flood levels during the base flood discharge.

b. The modification is for new construction or substantial improvement on lots contiguous to and surrounded by lots with existing structures constructed below the base flood level.

c. The granting of the modification will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud or victimization of the public or conflict with existing laws or ordinances.

d. The modification is the minimum necessary, considering the flood hazard, to afford relief and is consistent with the objectives of sound floodplain management. (Ord. 253, 12-16-2014)

An applicant may apply to FEMA for an adjustment to the designated base flood elevation and/or other designations on the FIRM or flood boundary maps. Prior to submitting such application to FEMA, all required documents required by FEMA must be submitted to the town for review and acknowledgment. Depending on the size, scope and specific design of a land use proposal within the town, an applicant for such proposal may be required to submit an application to FEMA for an adjustment to the base flood elevation. The town will determine if this FEMA application is actually required. (Ord. 253, 12-16-2014)