Temecula Municipal Code Art. V Provisions for Flood Hazard Reduction

In all areas of special flood hazards, all new construction and substantial improvements shall comply with the California Building Code (CBC) and the following standards:

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 15.12.180 "Standards for manufactured homes."

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. 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.

4. Require adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures.

C. Elevation and Floodproofing.

1. All new residential and nonresidential construction and substantial improvements shall have the pad elevation elevated to a minimum of one foot above the FIRM base flood elevation. Prior to issuance of building permit, the pad elevation shall be certified by a registered professional engineer or surveyor. Upon completion of the structure, the elevation of the lowest floor, including basement, shall be certified by a registered professional engineer or surveyor. The certification shall be prepared on FEMA's Elevation Certification Form and submitted to the floodplain administrator.

2. All new residential and nonresidential construction and substantial improvements in Zone AO shall have the pad elevation elevated to a minimum of one foot above the highest adjacent grade elevation of the FIRM base flood elevation, or at least two feet if there is no FIRM base elevation of the adjacent grade. Prior to issuance of building permit, the pad elevation shall be certified by a registered professional engineer or surveyor. Upon completion of the structure, the elevation of the lowest floor, including basement, shall be certified by a registered professional engineer or surveyor. The certification shall be prepared on FEMA's Elevation Certification Form and submitted to the floodplain administrator.

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

a. Be floodproofed 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 have been satisfied. Such certifications shall be prepared on FEMA's standard form and submitted to the floodplain administrator.

4. Require (for all new construction and substantial improvements with fully enclosed areas below the lowest floor) that areas, usable solely for parking of vehicles, building access or storage, and 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 have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding, have the bottom of all openings 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 by a registered professional engineer or architect in compliance to applicable floodproofing standards approved by FEMA.

5. Manufactured homes shall so meet the standards in Section 15.12.180 "Standards for manufactured homes."

6. Garages and Low-Cost Accessory Structures.

a. Attached Garages.

i. A garage attached to a residential structure, constructed with the garage floor slab below the base flood elevation (BFE) must be designed to allow for the automatic entry of flood waters. See subsection (C)(3). Areas of the garage below the BFE must be constructed with flood resistant materials. See subsection B.

ii. A garage attached to a nonresidential structure must meet the above requirements or be dry-proofed. For guidance on below grade parking areas, see FEMA Technical Bulletin TB-6.

b. Detached Garages and Accessory Structures.

i. "Accessory structure" used solely for parking (two-car detached garages or smaller) or limited storage (small, low-cost sheds), as defined in Article II "Definitions," may be constructed such that its floor is below the BFE, provided the structure is designed and constructed in accordance with the following requirements:

(A) Use of the accessory structure must be limited to parking or limited storage;

(B) The portion of the accessory structure below the BFE must be built using flood-resistant materials;

(C) The accessory structure must be adequately anchored to prevent flotation, collapse and lateral movement;

(D) Any mechanical and utility equipment in an accessory structure must be elevated or flood-proofed to or above the BFE;

(E) The accessory structure must comply with floodplain encroachment provisions in Section 15.12.200 "Floodways"; and

(F) The accessory structure must be designed to allow for the automatic entry of flood waters in accordance with subsection (C)(3).

ii. Detached garages and accessory structures not meeting the above standards must be constructed in accordance with the applicable standards in this section.

(Ord. 91-12 § 5.1; Ord. 13-05 § 4)

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 in Sections 15.12.150(B) "Construction materials and methods" and 15.12.170(D) "Standards for subdivisions."

(Ord. 91-12 § 5.2; Ord. 13-05 § 4)

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

B. All subdivision plans shall provide the elevation of proposed pad(s) and structure(s). The pad elevation(s) shall be elevated to a minimum of one foot above the FIRM base flood elevation and shall be certified by a registered professional engineer or surveyor and submitted to the floodplain administrator. Upon completion of the structure, the elevation of the lowest floor, including basement, shall be certified by a registered professional engineer or surveyor. The certification shall be prepared on FEMA's Elevation Certification Form and submitted to the floodplain administrator.

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

D. All subdivision proposals 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 provisions and improvements to reduce exposure to flood hazards.

(Ord. 91-12 § 5.3; Ord. 13-05 § 4)

A. All manufactured homes that are placed or substantially improved within a special flood hazard area on the community's FIRM: (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; and/or (4) in an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" as the result of a flood must:

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

B. All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision on the community's FIRM that are not subject to the provisions of subsection A will be elevated so that either:

1. The lowest floor of the manufactured home is elevated to a minimum of one foot above the FIRM 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 in height above grade and be securely anchored to an adequately anchored foundation system to resist floatation, collapse and lateral movement.

C. All manufactured homes to be placed or substantially improved on sites within Zones V1-30, V and VE on the community's FIRM shall meet the applicable standards of subsections A and B.

(Ord. 91-12 § 5.4; Ord. 13-05 § 4)

All recreational vehicles placed on sites within a floodplain shown on the community's FIRM shall either:

A. Be on the site for fewer than one hundred eighty consecutive days;

B. Be fully licensed and ready for highway use; or

C. Meet the permit requirements of Article IV "Administration" of this chapter and the elevation and anchoring requirements for manufactured homes in Section 15.12.180 "Standards for manufactured homes."

(Ord. 91-12 § 5.5; Ord. 13-05 § 4)

Located within areas of special flood hazard established in Section 15.12.070 "Basis for establishing the areas of special flood hazard" are areas designated as floodways. Since the floodway is 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 level 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 Article V "Provisions for Flood Hazard Reduction" of this chapter.

(Ord. 91-12 § 5.6; Ord. 13-05 § 4)

A. The floodplain administrator shall review permits for proposed construction of other developments to determine if they are 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 of quality of soils;

2. Evidence of ground water 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, excavation, 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 FIRM, the community shall adopt a drainage ordinance which at least complies with the standards of the California Building Code:

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, sub-drains, diverter terraces, benching, etc.; and

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

(Ord. 91-12 § 5.8; Ord. 13-05 § 4)

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

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 on the FIRM, 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 structure, 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. 91-12 § 5.9; Ord. 13-05 § 4)