Chapter 15.12 FLOOD DAMAGE PREVENTION

The Legislature of the State of California has in Government Code Sections 65302, 65560, and 65800 conferred upon local governments the authority to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the city council of the city of Hughson does hereby adopt the following floodplain management regulations. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.020 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 to:

A. Protect human life and health;

B. Minimize expenditure of public money for costly flood control projects;

C. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

D. Minimize prolonged business interruptions;

E. Minimize damage to public facilities and utilities such as water and gas mains; electric, telephone and sewer lines; and streets and bridges located in areas of special flood hazard;

F. 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 blighted areas caused by flood damage;

G. Ensure that potential buyers are notified that property is in an area of special flood hazard; and

H. Ensure that those who occupy the areas of special flood hazard assume responsibility for their actions. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

Article II. Definitions

15.12.100 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.

A. “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.

B. “Base flood” means a flood which has a one percent chance of being equaled or exceeded in any given year (also called the “100-year flood”). “Base flood” is the term used throughout this chapter.

C. “Basement” means, for the purpose of floodplain management, the portion of a building having its floor subgrade (below ground level) on all sides.

D. Building. See “structure.”

E. “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 or storage of equipment or materials.

F. “Flood” or “flooding” means:

1. A general and temporary condition of partial or complete inundation of normally dry land areas from: the overflow of inland or tidal waters; the unusual and rapid accumulation or runoff of surface waters from any source; or mudslides (i.e., mudflows) which are proximately caused by flooding as defined herein and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.

2. The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusual and unforeseeable event which results in flooding as defined in this definition.

G. “Flood Insurance Rate Map” (FIRM) means an official map of a community, on which the administrator has delineated both the special hazard areas and the risk premium zones applicable to the community.

H. “Floodplain” or “flood-prone area” means any land area susceptible to being inundated by water from any source – see “flooding.”

I. “Floodplain administrator” is the individual appointed to administer and enforce the floodplain management regulations.

J. “Floodplain management” means the operation of an overall program of corrective and preventive measures for reducing flood damage and preserving and enhancing, where possible, natural resources in the floodplain, including but not limited to emergency preparedness plans, flood control works, floodplain management regulations, and open space plans.

K. “Floodplain management regulations” means this chapter and other zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as grading and erosion control) and other application of police power which control development in flood-prone areas. This term describes federal, state or local regulations in any combination thereof which provide standards for preventing and reducing flood loss and damage.

L. “Floodproofing” means any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents.

M. “Governing body” is the local governing unit, i.e., county or municipality, that is empowered to adopt and implement regulations to provide for the public health, safety and general welfare of its citizenry.

N. “Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

O. “Historic structure” means any structure that is:

1. Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;

2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;

3. Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or

4. Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either by an approved state program as determined by the Secretary of the Interior or directly by the Secretary of the Interior in states with approved programs.

P. “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 HMC 15.12.400.

Q. “Manufactured home” means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term “manufactured home” does not include a “recreational vehicle.”

R. “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

S. “New construction,” for floodplain management purposes, means structures for which the “start of construction” commenced on or after the effective date of floodplain management regulations adopted by this community (September 26, 2008), and includes any subsequent improvements to such structures.

T. One-Hundred-Year Flood or 100-Year Flood. See “base flood.”

U. “Recreational vehicle” means a vehicle which is:

1. Built on a single chassis;

2. Four hundred square feet or less when measured at the largest horizontal projection;

3. Designed to be self-propelled or permanently towable by a light-duty truck; and

4. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

V. “Start of construction” includes substantial improvement and other proposed new development and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within 180 days from the date of the permit. 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 foundations 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. For a substantial improvement, the “actual start of construction” means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

W. “Structure” means a walled and roofed building that is principally above ground; this includes a gas or liquid storage tank or a manufactured home.

X. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

Y. “Substantial improvement” means any reconstruction, rehabilitation, addition, or other proposed new development of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the “start of construction” of the improvement. This term includes structures which have incurred “substantial damage,” regardless of the actual repair work performed. The term does not, however, include either:

1. Any project for improvement of a structure to correct existing violations or state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or

2. Any alteration of a “historic structure”; provided, that the alteration will not preclude the structure’s continued designation as a “historic structure.” (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

Article III. General Provisions

15.12.200 Lands to which this chapter applies.

This chapter shall apply to all areas identified as flood-prone within the jurisdiction of the city of Hughson. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.210 Basis for establishing flood-prone areas.

The areas of special flood hazard identified by the Federal Emergency Management Agency (FEMA) in the Flood Insurance Study (FIS) dated September 26, 2008, Stanislaus County, California, and Incorporated Areas with accompanying Flood Insurance Rate Maps (FIRMs) and Flood Boundary and Floodway Maps (FBFMs), dated September 26, 1980, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be part of this chapter. This FIS and attendant mapping are the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter and which are recommended to the city council by the floodplain administrator. The floodplain administrator shall obtain, review, and reasonably utilize any base flood data available from other federal or state agencies or other source to identify flood-prone areas within the jurisdiction of city of Hughson. This data will be on file at the city of Hughson, City Hall, 7018 Pine Street, Hughson, California, 95326. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.220 Compliance.

No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violation of the requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute a misdemeanor. Nothing herein shall prevent the city council from taking such lawful action as is necessary to prevent or remedy any violation. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.230 Abrogation and greater restrictions.

This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.240 Interpretation.

In the interpretation and application of this chapter, 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. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.250 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 manmade 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 council, city of Hughson, any officer or employee thereof, the state of California, the Federal Insurance Administration, or Federal Emergency Management Agency for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.260 Severability.

This chapter and the various parts thereof are hereby declared to be severable. Should any section of this chapter be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole, or any portion thereof other than the section so declared to be unconstitutional or invalid. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

Article IV. Administration

15.12.300 Permit.

Prior to issuance of any permit obtained for all proposed construction or other development in the community, including the placement of manufactured homes, a determination shall be made as to whether such construction or other development is within flood-prone areas. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.310 Designation of the floodplain administrator.

The community development director, as the floodplain administrator, is hereby appointed to administer, implement, and enforce this chapter by granting or denying development permits in accord with its provisions. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.320 Duties and responsibilities of the floodplain administrator.

The duties and responsibilities of the floodplain administrator shall include, but not be limited to, the following:

A. Permit Review. Review all development permit applications to determine:

1. Permit requirements of this chapter have been satisfied;

2. All other required state and federal permits have been obtained; and

3. The site is reasonably safe from flooding.

B. Review and Use of Any Other Base Flood Data. The floodplain administrator shall obtain, review, and reasonably utilize any base flood data available from other federal or state agency or other source.

C. Notification of Other Agencies.

1. Alteration or Relocation of a Watercourse.

a. Notify adjacent communities and the California Department of Water Resources prior to alteration or relocation;

b. Submit evidence of such notification to the Federal Emergency Management Agency; and

c. Assure that the flood carrying capacity within the altered or relocated portion of said watercourse is maintained.

2. Base Flood Elevation Changes Due to Physical Alterations.

a. Require applicants who submit hydrologic and hydraulic engineering analyses to support permit applications to submit to FEMA the data and information necessary to maintain the Flood Insurance Rate Maps when the analyses indicate changes in base flood elevations, flood hazard area boundaries, or floodway designations; such submissions shall be made within six months of such data becoming available.

3. Changes in Corporate Boundaries.

a. Notify FEMA in writing whenever the corporate boundaries have been modified by annexation or other means and include a copy of the map of the community clearly delineating the new corporate limits. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.330 Variances.

A. Nature of Variances. The considerations and conditions for variances set forth in this article are based on the general principle of zoning law that variances pertain to a piece of property and are not personal in nature. A variance may be issued for a parcel of property with physical characteristics so unusual that complying with the requirements of these regulations would create an exceptional hardship to the applicant or the surrounding property owners. The characteristics must be unique to the property and not be shared by adjacent parcels. The unique characteristic must pertain to the land itself, not to the structure, its inhabitants, or the property owners. The issuance of a variance is for floodplain management purposes only. Federal flood insurance premium rates are determined by the National Flood Insurance Program according to actuarial risk and will not be modified by the granting of a variance.

It is the duty of the city council to promote public health, safety and welfare and minimize losses from flooding. This duty is so compelling and the implications of property damage and the cost of insuring a structure built below flood level are so serious that variances from the elevation or other requirements in the building codes should be quite rare. The long-term goal of preventing and reducing flood loss and damage, and minimizing recovery costs, inconvenience, danger, and suffering, can only be met when variances are strictly limited. Therefore, the variance requirements in these regulations are detailed and contain multiple provisions that must be met before a variance can be properly issued. The criteria are designed to screen out those situations in which alternatives other than a variance are more appropriate.

B. Variances – General. The planning commission shall hear and decide requests for variances from the strict application of these regulations.

C. Limitations on Authority. The planning commission shall base its determination on technical justifications submitted by applicants, the considerations and conditions set forth in this article, the comments and recommendations of the floodplain administrator and building official, as applicable, and has the right to attach such conditions to variances as it deems necessary to further the purposes and objectives of these regulations and the building code.

D. Records. The floodplain administrator shall maintain a permanent record of all variance actions, including justification for issuance.

E. Historic Structures. A variance is authorized to be issued for the repair, improvement, or rehabilitation of a historic structure upon a determination that the proposed repair, improvement, or rehabilitation will not preclude the structure’s continued designation as a historic structure, and the variance is the minimum necessary to preserve the historic character and design of the structure. When the proposed work precludes the structure’s continued designation as a historic building, a variance shall not be granted and the structure and any repair, improvement, and rehabilitation shall be subject to the requirements of the building code.

F. Restrictions in Floodways. A variance shall not be issued for any proposed development in a floodway when any increase in flood levels would result during the base flood discharge, as evidenced by the applicable analysis required in HMC 15.12.320(C)(2).

G. Functionally Dependent Uses. A variance is authorized to be issued for the construction or substantial improvement necessary for the conduct of a functionally dependent use provided the criteria in Section 1612 of the building code (CCR Title 24 Part 2) or Section R322 of the residential code (CCR Title 24 Part 2.5) are met, as applicable, and the variance is the minimum necessary to allow the construction or substantial improvement, and that all due consideration has been given to use of methods and materials that minimize flood damages during the base flood and create no additional threats to public safety.

H. Agricultural Structures. A variance is authorized to be issued for the construction or substantial improvement of agricultural structures that are not elevated or dry floodproofed, provided the requirements of this section are satisfied and:

1. A determination has been made that the proposed agricultural structure:

a. Is used exclusively in connection with the production, harvesting, storage, raising, or drying of agricultural commodities and livestock, or storage of tools or equipment used in connection with these purposes or uses, and will be restricted to such exclusive uses.

b. Has low damage potential.

c. Does not increase risks and pose a danger to public health, safety, and welfare if flooded and contents are released, including but not limited to the effects of flooding on manure storage, livestock confinement operations, liquified natural gas terminals, and production and storage of highly volatile, toxic, or water-reactive materials.

d. Complies with the wet floodproofing construction requirements of subsection (H)(2) of this section.

2. Wet Floodproofing Construction Requirements.

a. Anchored to resist flotation, collapse, and lateral movement.

b. When enclosed by walls, walls have flood openings that comply with the flood opening requirements of ASCE 24, Chapter 2.

c. Flood-damage-resistant materials are used below the base flood elevation.

d. Mechanical, electrical, and utility equipment is elevated above the base flood elevation.

I. Considerations for Issuance of Variances. In reviewing applications for variances, all technical evaluations, all relevant factors, all other requirements of these regulations and the building code, as applicable, and the following shall be considered:

1. The danger that materials and debris may be swept onto other lands resulting in further injury or damage.

2. The danger to life and property due to flooding or erosion damage.

3. The susceptibility of the proposed development, including contents, to flood damage and the effect of such damage on current and future owners.

4. The importance of the services provided by the proposed development to the community.

5. The availability of alternate locations for the proposed development that are not subject to flooding or erosion and the necessity of a waterfront location, where applicable.

6. The compatibility of the proposed development with existing and anticipated development.

7. The relationship of the proposed development to the comprehensive plan and floodplain management program for that area.

8. The safety of access to the property in times of flood for ordinary and emergency vehicles.

9. The expected heights, velocity, duration, rate of rise and debris and sediment transport of the floodwater and the effects of wave action, if applicable, expected at the site.

10. 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, streets and bridges.

J. Conditions for Issuance of Variances. Variances shall only be issued upon:

1. Submission by the applicant of a showing of good and sufficient cause that the unique characteristics of the size, configuration, or topography of the site limit compliance with any provision of these regulations or renders the elevation standards of the building code inappropriate.

2. A determination that failure to grant the variance would result in exceptional hardship due to the physical characteristics of the land that render the lot undevelopable.

3. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, nor create nuisances, cause fraud on or victimization of the public or future property owners, or conflict with existing local laws or ordinances.

4. A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

5. When the request is to allow construction of the lowest floor of a new building or substantial improvement of a building below the base flood elevation, notification to the applicant in writing over the signature of the floodplain administrator specifying the difference between the base flood elevation and the proposed elevation of the lowest floor, stating that issuance of a variance to construct below the elevation required in the building code will result in increased premium rates for federal flood insurance up to amounts as high as $25.00 for $100.00 of insurance coverage, and that such construction below the required elevation increases risks to life and property. (Ord. 23-03 §§ 1, 2, 2023; Ord. 21-06 § 1, 2021)

Article V. Provisions for Flood Hazard Reduction

15.12.400 Standards of construction.

If a proposed building site is in a flood-prone area, all new construction and substantial improvements, including manufactured homes, shall:

A. Be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

B. Be constructed:

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. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.410 Standards for subdivisions or other proposed new development.

If a subdivision proposal or other proposed new development, including manufactured home parks or subdivisions, is in a flood-prone area, any such proposals shall be reviewed to assure that:

A. All such proposals are consistent with the need to minimize flood damage within the flood-prone area;

B. All public utilities and facilities such as sewer, gas, electrical, and water systems are located and constructed to minimize or eliminate flood damage; and

C. Adequate drainage is provided to reduce exposure to flood hazards.

D. In addition to the requirements of this section, where any portion of proposed subdivisions, including proposals for manufactured home parks and subdivisions, lies within a flood hazard area, the following shall be required:

1. The flood hazard area shall be delineated on preliminary subdivision plats.

2. Where the subdivision has more than 50 lots or is larger than five acres and base flood elevations are not included on the FIRM, the base flood elevations shall be determined by the floodplain administrator in accordance with this chapter at the expense of the proposer of the subdivision.

3. When, as part of a proposed subdivision, fill will be placed to support buildings, the fill shall be placed in accordance with the building code and approval of the subdivision shall require submission of as-built elevations for each filled pad certified by a licensed land surveyor or registered civil engineer. (Ord. 23-03 § 3, 2023; Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.420 Standards for utilities.

A. All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate:

1. Infiltration of flood waters into the systems; and

2. Discharge from the systems into flood waters.

B. On-site waste disposal systems shall be located to avoid impairment to them, or contamination from them during flooding. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020; Ord. 16-05 § 1, 2016)

15.12.430 Floodways.

Until a regulated floodway is adopted, no new construction, substantial development, or other development (including infill) shall be permitted within Zone A unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other development, will not increase the water surface elevation of the base flood more than one foot at any point within the lands under the jurisdiction of the city of Hughson. (Ord. 21-06 § 1, 2021; Ord. 20-02 § 1, 2020)