Chapter 8.50

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.

“Accessory use” means a use that is incidental and subordinate to the principal use of the parcel of land on which it is located.

“Alluvial fan” means a geomorphologic feature characterized by a cone or fan-shaped deposit of boulders, gravel, and fine sediments that have been eroded from mountain slopes, transported by flood flows, and then deposited on the valley floors, and which is subject to flash flooding, high velocity flows, debris flows, erosion, sediment movement and deposition, and channel migration.

“Apex” means the point of highest elevation on an alluvial fan, which on undisturbed fans is generally the point where the major stream that formed the fan emerges from the mountain front.

“Appeal” means a request for a review of the city engineer’s interpretation of any provision of this chapter or request for a variance.

“Area of shallow flooding” means a designated AO or AH Zone on the flood insurance rate map (FIRM). The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.

“Area of special flood hazard.” See “special flood hazard area (SFHA)”.

“Area of special flood-related erosion hazard” is the land within the community, which is most likely to be subject to severe flood-related erosion losses. The area may be designated as Zone E on the flood insurance rate map (FIRM).

“Area of special mudslide (i.e., mudflow) hazard” is the area subject to severe mudslides (i.e., mudflows). The area is designated as Zone M on the flood insurance rate map (FIRM).

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

“Basement” means any area of the building having its floor sub-grade (below grade level) on all sides.

“Breakaway walls” are any type of walls, whether solid or lattice, and whether constructed of concrete, masonry, wood, metal, plastic, or any other suitable building material which is not part of the structural support of the building and which is designed to break away under abnormally high tides or wave action without causing any damage to the structural integrity of the building on which they are used of any buildings to which they might be carried by floodwaters. A breakaway wall shall have a safe design loading resistance of not less than ten or more than twenty pounds per square foot. Use of breakaway walls must be certified by a registered engineer or architect and shall meet the following conditions:

1. Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and

2. The elevated portion of the building shall not incur any structural damage due to the effects of wind and water loads acting simultaneously in the event of the base flood.

“Building”: see definition of “structure.”

“Coastal high hazard area” means an area of special flood hazard extending from offshore to an inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms or seismic sources. It is the area subject to high velocity waters, including coastal and tidal inundation or tsunamis. The area is designated on the flood insurance rate map (FIRM) as zone VI – V30, VE or V.

“Development” means any man-made 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.

“Encroachment” means the advance or infringement of uses, plant growth, fill, excavation, buildings, permanent structures or development into a floodplain, which may impede or alter the flow capacity of a floodplain.

“Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by the city of Millbrae.

“Expansion to an existing manufactured home park or subdivision” means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either site grading or the pouring of concrete pads).

“Flood or flooding or flood water” 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, and/or mudslides (i.e., mudflows).

2. The condition resulting from flood-related erosion.

“Flood boundary and floodway map (FBFM)” means the official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of flood hazard and the floodway.

“Flood hazard boundary map (FHBM)” means an official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated the areas of flood hazards.

“Flood insurance rate map (FIRM)” means the official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of special flood hazards and the risks premium zones applicable to the community.

“Flood insurance study” means the official report provided by the Federal Insurance Administration that includes flood profiles, the flood insurance rate map (FIRM), the flood boundary and floodway map, and the water surface elevation of the base flood.

“Flood-related erosion” means the collapse or subsidence of land along the shore of a lake or other boundary of water as a result of undermining caused by waves or currents of water exceeding anticipated cyclical level or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an abnormal tidal surge, or some similarly unusually and unforeseen event which results in flooding.

“Flood-related erosion area” or “flood-related erosion prone area” means a land area adjoining the shore of a lake or other body of water which, due to the composition of the shoreline or bank and high water levels or wind-driven currents, is likely to suffer flood-related erosion damage.

“Flood-related erosion area management” means the operation of an overall program of corrective and preventive measures for reducing flood-related erosion damage, including but not limited to emergency preparedness plans, flood-related erosion control works, and floodplain management regulations.

“Floodplain or flood-prone area” means any land area susceptible to being inundated by water from any source (see definition of “flooding”).

“Floodplain administrator” is the individual appointed to administer and enforce the floodplain management regulations. The appointed individual for the city of Millbrae shall be the city engineer.

“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 and floodplain management regulations, and open space plans.

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

“Flood proofing” means any combination of structural and nonstructural additions, changes or adjustments to structures that reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents. (See FEMA Technical Bulletins TB 1-93, TB 3-93, and TB 7-93 or most current technical bulletin for guidelines on dry and wet flood proofing.)

“Floodway” means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot. This is also referred to as “regulatory floodway.”

“Floodway fringe” is that area of the floodplain on either side of the “regulatory floodway” where encroachment may be permitted.

“Fraud and victimization,” as related to variances granted under MMC 8.50.230, means that the variance granted must not cause fraud on or victimization of the public. In examining this requirement, City of Millbrae will consider the fact that every newly constructed building adds to government responsibilities and remains a part of the community for fifty to one hundred years. Buildings that are permitted to be constructed below the base flood elevation are subject during all those years to increased risk of damage from floods, while future owners of the property and the community as a whole are subject to all the costs, inconvenience, danger, and suffering that those increased flood damages bring. In addition, future owners may purchase the property, unaware that it is subject to potential flood damage and can be insured only at very high flood insurance rates.

“Functionally dependent use” means a use that cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and shipbuilding and ship repair facilities, but does not include long-term storage or related manufacturing facilities.

“Governing body” is the local government, 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.

“Hardship,” as it relates to variances granted under MMC 8.50.230, means the exceptional hardship that would result from a failure to grant the requested variance. The city of Millbrae requires that the variance be exceptional, unusual, and peculiar to the property involved. Mere economic or financial hardship alone is not exceptional. Inconvenience, aesthetic considerations, physical handicaps, personal preferences, or the disapproval of one’s neighbor likewise cannot, as a rule, qualify as an exceptional hardship. All of these problems can be resolved through other means without granting a variance, even if the alternative is more expensive, or requires the property owner to build elsewhere or put the parcel to a different use than originally intended.

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

“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 preliminary determination 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 without approved programs.

“Levee” means a man-made structure, usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control or divert the flow of water so as to provide protection from temporary flooding.

“Levee system” means a flood protection system that consists of a levee or levees, and associated structures such as closure and drainage devices, which are constructed and operated in accord with sound engineering practices.

“Lowest floor” means the lowest floor of the lowest enclosed area (including basement) (see “Basement” definition).

1. 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 it conforms to applicable non-elevation design requirements, including, but not limited to:

a. The wet flood proofing standard in MMC 8.50.140;

b. The anchoring standards in MMC 8.50.170;

c. The construction materials and methods standards in MMC 8.50.140; and

d. The standards for utilities in MMC 8.50.150.

2. For residential structures, all subgrade enclosed areas are considered to be basements (see “basement” definition), not lowest floors. This includes below-grade garages and storage areas.

“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 connected to the required utilities. The term “manufactured home” does not include a “recreational vehicle.”

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

“Market value” shall be determined by estimating the cost to replace the structure in new condition and adjusting that cost figure by the amount of depreciation which has accrued since the structure was constructed. The cost of replacement of the structure shall be based on a square foot cost factor determined by reference to a building cost estimating guide recognized by the building construction industry. The amount of depreciation shall be determined by taking into account the age and physical deterioration of the structure and functional obsolescence as approved by the floodplain administrator, but shall not include economic or other forms of external obsolescence. Use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be considered only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences.

“Mean sea level” means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a community’s flood insurance rate map are referenced.

“Mudslide” describes a condition where there is a river, flow or inundation of liquid mud down a hillside, usually as a result of a dual condition of loss of brush over, and the subsequent accumulation of water on the ground, preceded by a period of unusually heavy or sustained rain.

“Mudslide (i.e., mudflow) prone area” means an area with land surfaces and slopes of unconsolidated material where history, geology, and climate indicate a potential for mudflow.

“New construction” means, for floodplain management purposes, structures for which the “start of construction” commenced on or after the effective date of a floodplain management regulation adopted by this community.

“New manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is complete on or after the effective date of floodplain management regulations adopted by the city of Millbrae.

“Obstruction” includes, but is not limited to, any dam, wall, wharf, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, building, fence, rock, gravel, refuse, fill, structure, vegetation, or other material in, along, across or projecting into any watercourse which may alter, impede, retard or change the direction and/or velocity of the flow of water, or due to its location, its propensity to snare or collect debris carried by the flow of water, or its likelihood of being carried downstream.

“One hundred year flood” or “100-year flood” means a flood which has one percent annual probability of being equaled or exceeded. It is identical to the “base flood,” which will be the term used throughout this chapter.

“Primary frontal dune” means a continuous or nearly continuous mound or ridge of sand with relatively steep seaward and landward slopes immediately landward and adjacent to the beach and subject to erosion and overtopping from high tides and waves during major storms. The inland limit of the primary frontal dune occurs at the point where there is a distinct change from a relatively mild slope.

“Public safety and nuisance,” as used in MMC 8.50.230, means anything that is injurious to safety or health of an entire community or neighborhood, or any considerable number of persons, or unlawfully obstructs the free passage or use, in the customary manner, of any navigable lake, or river, bay, stream, canal, or basin.

“Recreational vehicle” means a vehicle which is:

1. Built on a single chassis;

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

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

4. Designed primarily as temporary living quarters for recreation, camping, travel, or seasonal use (not for use as a permanent dwelling).

“Regulatory floodway” means a channel of a river or other watercourse and the adjacent land area that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.

“Person” means an individual or his agent, firm, partnership, corporations, association or cooperation, or agent of the aforementioned groups, or this state or its agencies or political subdivisions.

“Remedy a violation” means to bring the structure or other development into compliance with state or local floodplain management regulations, or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of this chapter or otherwise deterring future similar violations, or reducing state or federal financial exposure with regard to the structure or other development.

“Riverine” means relating to, formed by or resembling a river (including tributaries), stream and brook among others.

“Sand dunes” means naturally occurring accumulations of sand in ridges or mounds landward of the beach.

“Sheet flow area” – See “area of shallow flooding.”

“Special flood hazard area (SFHA)” means an area in the floodplain subject to a one percent or greater chance of flooding in any given year, and is shown on an FHBM or FIRM as Zone A, AO, A1 – A30, AE, A99, AH or V1 – V30, VE or V.

“Start of construction” includes substantial improvement, and other proposed development and means the date the building permit was issued, provided the actual start date of construction, repair, reconstruction, rehabilitation, addition, placement or other improvement was within one hundred eighty 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 pouring a 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 of 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.

“Structure” means a walled and roofed building, including a gas or liquid storage tank that is principally above ground, as well as a manufactured home.

“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 fifty percent of the market value of the structure before the damage occurred.

“Substantial improvement” means any repair, rehabilitation, addition or other proposed new development of a structure, the cost of which equals or exceeds fifty 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 of 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.”

“V Zone” – See “coastal high hazard area.”

“Variance” means a grant of relief from the requirements of this chapter (i.e., permits construction in a manner that would otherwise be prohibited by this chapter).

“Violation” means the failure of a structure or development to be fully compliant with the community’s floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in this chapter is presumed to be in violation until such time as that documentation is provided.

“Water surface elevation” means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929, (or other datum, where specified) of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas.

“Watercourse” means a lake, river, creek, stream, wash, arroyo, channel or other topographic designated areas in which substantial damage may occur. (Ord. 688, § 1; 1976 Code § 8-10.02).

8.50.030 Lands to which this chapter applies.

This chapter shall apply to all areas of special flood hazard within the jurisdiction of the city of Millbrae. (Ord. 688, § 1; 1976 Code § 8-10.03).

8.50.040 Basis for establishing the areas of special flood hazard.

The areas of special flood hazard identified by the Federal Insurance Administration (FIA) of the Federal Emergency Management Agency (FEMA) in the flood insurance study (FIS) dated March 30, 1981, and accompanying flood insurance rate maps (FIRMs) and flood boundary and floodway maps (FBFMs), dated September 30, 1981, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this chapter. This FIS and attendant mapping is 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 study, FIRMs, and FBFMs are on file at City Hall, 621 Magnolia Ave., Millbrae, California, 94030. (Ord. 688, § 1; 1976 Code § 8-10.04).

8.50.050 Compliance required – Violation constitutes misdemeanor penalty.

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. Violations of the provisions of this chapter by failure to comply with any of its 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.

Any person convicted of a misdemeanor under the provisions of this chapter shall be punishable by a fine of not more than one thousand dollars, or imprisonment in the county jail for a period of not exceeding six months, or by both a fine and imprisonment. (Ord. 688, § 1; 1976 Code § 8-10.05).

8.50.060 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. 688, § 1; 1976 Code § 8-10.06).

8.50.070 Interpretation.

In the interpretation and application of this chapter, all provisions shall be:

A. Considered as minimum requirements;

B. Liberally construed in favor of the governing body; and

C. Deemed neither to limit nor repeal any other powers granted under state statutes. (Ord. 688, § 1; 1976 Code § 8-10.07).

8.50.080 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 man-made or natural causes. This chapter does not imply that land outside the areas of special flood hazards or uses permitted within such area will be free from flooding or flood damages. This chapter shall not create liability on the part of the city, any officer or employee thereof, the State of California, or the Federal Insurance Administration, Federal Emergency Management Agency, for any flood damage that resulted from reliance on this chapter or any administration decision lawfully made hereunder. (Ord. 688, § 1; 1976 Code § 8-10.08).

8.50.090 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. 688, § 1; 1976 Code § 8-10.09).

8.50.100 Establishment of development permit.

A development permit shall be obtained before construction or other development begins within any area of special flood hazard established in MMC 8.50.040. Application for a development permit shall be made on forms furnished by the floodplain administrator, and may include, but are not limited to: plans in duplicate drawn to scale showing the nature, location, dimensions and elevation of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, all of the information listed in subsections (A) through (E) of this section is required.

A. Site plan, including but not limited to:

1. Spot ground elevations at the corners of all structures and at twenty-foot or smaller intervals along the foundation footprint, or one-foot contour elevations throughout the building site;

2. Proposed locations of water supply, sanitary sewer, and utilities;

3. If available, the base flood elevation from the flood insurance study and/or flood insurance rate map; and

4. If applicable, the location of the regulatory floodway.

B. Foundation design detail, including but not limited to:

1. Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;

2. For crawl-space foundation, location and total net area of foundation openings as required in MMC 8.50.140 and FEMA Technical Bulletins 1-93 and 7-93; and

3. For foundations placed on fill, the location and height of fill, and compaction requirements (compacted to ninety-five percent using Standard Proctor Test method).

C. Proposed elevation in relation to mean sea level, to which any nonresidential structure will be flood proofed, as required in MMC 8.50.140 and FEMA Technical Bulletin TB 3-93.

D. All appropriate certifications listed in MMC 8.50.120.

E. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. (Ord. 688, § 1; 1976 Code § 8-10.10).

8.50.110 Designation of the floodplain administrator.

The city engineer/director of public works of the city of Millbrae is hereby appointed to administer, implement, and enforce this chapter by granting or denying development permits in accordance with its provisions. (Ord. 688, § 1; 1976 Code § 8-10.11).

8.50.120 Duties and responsibilities of the floodplain administrator.

The duties and responsibilities of the floodplain administrator shall include, but not be limited to, those described in subsections (A) through (F) of this section.

A. Permit Review. Review all development permits to determine that:

1. The permit requirements of this chapter have been satisfied;

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

3. The site is reasonably safe from flooding; and

4. The proposed development does not adversely affect the carrying capacity of areas where base flood elevations have been determined but a floodway has not been designated. For the purposes of this chapter, “adversely affects” means that the cumulative effect of the proposed development when combined with all other existing and anticipated development will increase the water surface elevation of the base flood more than one foot at any point.

B. Review, Use and Development of Other Base Flood Data.

1. When base flood elevation data has not been provided in accordance with MMC 8.50.040, the floodplain administrator shall obtain, review and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer MMC 8.50.140 to 8.50.220, inclusive. Any such information shall be submitted to the city council for adoption.

2. If no base flood elevation is available from a federal or state agency or other source, then, in order to administer MMC 8.50.040, a base elevation shall be obtained using one of two methods from the FEMA publication “Managing Floodplain Development in Approximate Zone A Areas – A Guide for Obtaining and Developing Base (One Hundred Year) Flood Elevations,” dated July 1995, as described below.

a. Simplified Method.

(1) One hundred year or base discharge shall be obtained using the appropriate regression equation found in a U.S. Geological Survey publication, or the discharge-drainage area method; and

(2) Base flood elevation shall be obtained using the quick-2 computer program developed by FEMA.

b. Detailed Method.

(1) One hundred year or base flood discharge shall be obtained using the U.S. Army Corps of Engineers HEC-HMS computer program; and

(2) Base flood elevation shall be obtained using the U.S. Army Corps of Engineers HEC-RAS computer program.

C. Notification of Other Agencies. Whenever a watercourse is to be altered or relocated the floodplain administrator may:

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

2. Submit evidence of such notification to the Federal Insurance Administration, Federal Emergency Management Agency; and

3. Monitor the flood carrying capacity of the altered or relocated portion of said watercourse.

D. Documentation of Floodplain Development. Obtain and maintain for public inspection the following:

1. The certification required in MMC 8.50.140 (lowest floor elevation);

2. The certification required in MMC 8.50.140 (elevation or flood proofing of nonresidential structures);

3. The certification required in MMC 8.50.140 (wet flood proofing standard);

4. The certification required in MMC 8.50.160 (subdivision standards);

5. The certified elevation required in MMC 8.50.190 (floodway encroachments);

6. The certification required in MMC 8.50.200 (coastal construction standards); and

7. The information required in MMC 8.50.210 (mudflow standards).

E. Map Determinations. Make interpretations where needed, as to exact location of the boundaries of the areas of special flood hazard. Where there appears to be a conflict between a mapped boundary and actual field conditions, grade and base flood elevations shall be used to determine the boundaries of the special flood hazard area. The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in MMC 8.50.230 and 8.50.240.

F. Remedial Action. Take action to remedy violations of the chapter as specified in MMC 8.50.050. (Ord. 688, § 1; 1976 Code § 8-10.12).

8.50.130 Appeals.

The city council of the city of Millbrae shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the floodplain administrator in the enforcement or administration of this chapter. (Ord. 688, § 1; 1976 Code § 8-10.13).

8.50.140 Standards of construction.

In all areas of special flood hazards, the standards described in subsections (A) through (C) of this section are required.

A. Anchoring.

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

2. All manufactured homes shall meet the anchoring standards of MMC 8.50.170.

B. Construction Materials and Methods. All new construction and substantial improvements shall be constructed:

1. With materials and utility equipment resistant to flooding (as specified in FEMA Technical Bulletin TB 2-93, 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. If within Zones AH or AO, so that there are adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.

C. Elevation and Flood Proofing. (See MMC 8.50.020 of definitions for “basement,” “lowest floor,” “new construction,” “substantial damage” and “substantial improvement.”)

1. Residential construction, new or substantial improvement, shall have the lowest floor including basement:

a. In an AO zone, elevated above the highest adjacent grade to a height equal to or exceeding one foot above the depth number specified in feet on the FIRM, or elevated at least two feet above the highest adjacent grade if no depth number is specified;

b. In an A zone, elevated to or above the base flood elevation by at least two feet; said base flood elevation shall be determined by one of the methods in MMC 8.50.120; and

c. In all other zones, elevated to or above the base flood elevation by at least two feet.

Upon completion of the structure, the elevation of the lowest floor including basement shall be certified by a professional engineer or surveyor, and verified by the building inspector to be properly elevated. Such certification and verification shall be provided to the floodplain administrator.

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

a. Be flood proofed below the elevation recommended under subsection (C)(1) of this section 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 certification 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 floodwaters. Designs for meeting this requirement shall follow the guidelines in FEMA Technical Bulletins TB 1-93 and TB 7-93, and must exceed the following minimum criteria:

a. 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. 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 flood waters; or

b. Be certified by a registered professional engineer or architect.

4. Manufactured homes shall also meet the standards in MMC 8.50.170. (Ord. 688, § 1; 1976 Code § 8-10.14).

8.50.150 Standards for utilities.

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

1. Infiltration of floodwaters into the system; 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. (Ord. 688, § 1; 1976 Code § 8-10.15).

8.50.160 Standards for subdivisions.

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

B. All final subdivision plans will provide the elevation of proposed structure(s) and pad(s). If the site is filled above the base flood, the final pad elevation shall be certified by the 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. 688, § 1; 1976 Code § 8-10.16).

8.50.170 Standards for manufactured homes.

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:

1. Adjacent to 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; or

4. In an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred “substantial damage” as a result of a flood, shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated above the base flood elevation by at least two feet and be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

B. All manufactured homes that are placed or substantially improved on sites located within zones V1 – 30, V, and VE on the community’s flood insurance rate map will meet the requirements of this section and MMC 8.50.200.

C. All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within zones A1 – 30, AH, AE, V1 – 30, V, and VE on the community’s flood insurance rate map that are not subject to the provisions of this section will be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement, and be elevated so that either:

1. The lowest floor of the manufactured home is at or above the base flood elevation by at least two feet; or

2. Manufactured home chassis is supported by reinforcing piers or other foundation elements of at least equivalent strength that are no less than thirty-six inches in height above grade.

Upon 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 building inspector to be properly elevated. Such certification and verification shall be provided to the floodplain administrator. (Ord. 688, § 1; 1976 Code § 8-10.17).

8.50.180 Standards for recreational vehicles.

A. All recreational vehicles placed on sites within zones A1 – 30, AH and AE on the community’s flood insurance rate map will either:

1. Meet the permit requirements of MMC 8.50.100 and the elevation and anchoring requirements for manufactured homes in MMC 8.50.170; or

2. Be on the site for fewer than one hundred eighty consecutive days, and 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 permanent attached additions.

B. Recreational vehicles placed on sites within zones V1 – 30, V, and VE on the community’s flood insurance rate map will meet the requirements of this section and MMC 8.50.200. (Ord. 688, § 1; 1976 Code § 8-10.18).

8.50.190 Floodways.

Located within areas of special flood hazard established in MMC 8.50.040 are areas designated as floodways. 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. All encroachments are prohibited, including fill, new construction, substantial improvements and other development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in the base flood levels during the occurrence of the base flood discharge; and

B. If MMC 8.50.200(A) is satisfied, all new construction, substantial improvement, and other proposed new development shall comply with all other applicable flood hazard reduction provisions of MMC 8.50.140 to 8.50.220, inclusive. (Ord. 688, § 1; 1976 Code § 8-10.19).

8.50.200 Coastal high hazard areas.

Within coastal high hazard areas established in MMC 8.50.040, the following standards shall apply:

A. All new construction and substantial improvements shall be elevated on adequately anchored pilings or columns and securely anchored to such pilings or columns so that the lowest horizontal portion of the structural members of the lowest floor (excluding the piling or columns) is elevated to or above the base flood elevation. The pile or column foundation and structure attached thereto must be anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Water loading values used shall be those associated with the base flood. Wind loading values used shall be those required by applicable state or local building standards;

B. All new construction and other development shall be located on the landward side of the reach of mean high tide;

C. All new construction and substantial improvements shall have the space below the lowest floor free of obstructions or constructed with breakaway walls as defined in MMC 8.50.020. Such enclosed space shall not be used for human habitation and will be usable solely for parking of vehicles, building access or storage;

D. Fill shall not be used for structural support of buildings;

E. Man-made alteration of sand dunes that would increase potential flood damage is prohibited; and

F. The floodplain administrator shall obtain and maintain the following records:

1. Certification by a registered professional engineer or architect that a proposed structure complies with subsection (A) of this section; and

2. The elevation (in relation to mean sea level) of the bottom of the lowest structural member of the lowest floor (excluding pilings or columns) of all new and substantially improved structures, and whether such structures contain a basement. (Ord. 688, § 1; 1976 Code § 8-10.20).

8.50.210 Mudslide (i.e., mudflow) prone areas.

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

B. Permits shall be reviewed to determine that the proposed site and improvement will be 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 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 that may have mudslide hazards, the floodplain administrator shall require that:

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

2. The proposed grading, excavation, new construction and substantial improvement are adequately designed and protected against mudslide damage;

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. (Ord. 688, § 1; 1976 Code § 8-10.21).

8.50.220 Flood-related erosion-prone area.

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

B. Permit applications 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 the proposed improvement is found to be in the path of flood-related erosion, adequate protective measures shall be taken to avoid aggravating the existing erosion hazard.

D. Within zone E on the flood insurance rate map, a setback is required for all new development from 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 designed according to the flood-related erosion hazard and erosion rate, in relation to the anticipated “useful life” of structures, and depending upon geologic, hydrologic, topographic, and climatic characteristics of the land. The buffer may be used for suitable open space purposes, such as for agriculture, forestry, outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only. (Ord. 688, § 1; 1976 Code § 8-10.22).

8.50.230 Variance procedure.

The variance criteria set forth in this section 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 granted for a parcel of property with physical characteristics so unusual that complying with the requirements of this chapter 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 structures, its inhabitants, or the property owners.

It is the duty of the city council of the city of Millbrae to help protect its citizens from flooding. This need is so compelling and the implications of the cost of insuring structures built below the flood level are so serious that variances from the flood elevation or from other requirements in the flood chapter are quite rare. The long-term goal of preventing and reducing flood loss and damage can only be met if variances are strictly limited. Therefore, the variance guidelines provided in this chapter are more detailed and contain multiple provisions that must be met before a variance can be properly granted. The criteria are designed to screen out those situations in which alternatives other than a variance are more appropriate. (Ord. 688, § 1; 1976 Code § 8-10.23).

8.50.240 Variance appeal board.

A. In passing upon applications for variances, the city council shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and all of the following:

1. The danger that materials may be swept onto other lands to the injury of others;

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

3. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner and future owners of the property;

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

5. The necessity to the facility of a waterfront location, where applicable;

6. The availability of alternate locations for the proposed use which are not subject to flooding or erosion damage;

7. The compatibility of the proposed use with existing and anticipated development;

8. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;

9. Safety of access to the property in time of flood for ordinary and emergency vehicles;

10. The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters expected at the site; and

11. 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, and streets and bridges.

B. Any applicant to whom a variance is granted shall be given written notice over the signature of a community official. It is recommended that a copy of the notice shall be recorded by the floodplain administrator in the Office of the San Mateo County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land. The notice shall indicate that:

1. The issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as twenty-five dollars for one hundred dollars of insurance coverage; and

2. Such construction below the base flood level increases risks to life and property.

C. The floodplain administrator shall maintain the records of all appeal-variance actions, including justification for their issuance, and report any variances issued in its biennial report submitted to the Federal Insurance Administration, Federal Emergency Management Agency. (Ord. 688, § 1; 1976 Code § 8-10.24).

8.50.250 Condition for variances.

A. Generally, variances may be issued for new construction, substantial improvement, and other proposed new development to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing that the procedures in MMC 8.50.240 have been fully considered. As the lot size increases beyond one-half acre, the technical justification required for issuing the variance increases.

B. Variances may be issued for the repair or rehabilitation of “historic structures” (as defined in MMC 8.50.020) upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as an historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure.

C. Variances shall only be issued within any mapped regulatory floodway if no increase in flood levels during the base flood discharge would result.

D. Variances shall only be issued upon a determination that the variance is the “minimum necessary” considering the flood hazard, to afford relief. “Minimum necessary” means to afford relief with a minimum of deviation from the requirements of this chapter. For example, in the case of variances to elevation requirements, this means the city council of the city of Millbrae need not grant permission for the applicant to build at grade, or even to whatever elevation the applicant proposes, but only to that elevation which the city council believes will both provide relief and preserve the integrity of the local chapter.

E. Variances shall only be issued upon:

1. A showing of good cause;

2. Determination that failure to grant the variance would result in exceptional “hardship” (as defined in MMC 8.50.020) to the applicant; and

3. Determination that the granting of a variance would not result in increased flood heights, additional threats to public safety, or extraordinary public expense, create a nuisance (as defined in MMC 8.50.020 – See “public nuisance”), cause fraud or victimization (as defined in MMC 8.50.020) of the public, or conflict with local laws or ordinances.

F. Variances may be issued for new construction, substantial improvement, and other proposed new development necessary for the conduct of a functionally dependant use provided that the provisions of MMC 8.50.230 through 8.50.250 are satisfied and that the structure or other development is protected by methods that minimize flood damages during the base flood and does not result in additional threats to public safety and does not create a public nuisance.

G. Upon consideration of the factors of MMC 8.50.230 and the purposes of this chapter, the city council of the city of Millbrae may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter. (Ord. 688, § 1; 1976 Code § 8-10.25).

8.50.260 Administrative policy and procedure 1-19.

This policy and procedure is being restated herein in its entirety. The more stringent requirements of this policy and procedure or this chapter shall take precedence.

The purpose of this administrative procedure is to set forth the specific policies and procedures necessary to implement and to comply with the National Flood Insurance Program (NFIP) as it relates to residential and commercial properties located within the floodplains of the city of Millbrae.

A. Policy.

1. As a requirement of the Federal Emergency Management Agency (FEMA) and the State of California Department of Water Resources (DWR), the city shall establish written policies and procedures for the implementation of and compliance with the NFIP.

2. The following personnel shall be responsible for the implementation and compliance with the NFIP program: The city planner, building official and city engineer.

3. Public storm drain infrastructure shall be maintained in satisfactory working condition.

4. Designated employees shall maintain current knowledge of NFIP regulations and requirements through training offered by state and federal agencies, other sources acceptable to FEMA and/or DWR. The public works department shall maintain a set of compliance manuals, documentation, and compliance forms.

5. Designated staff shall participate in the community assistance visit (CAV) as required by FEMA and/or DWR.

B. Summary.

1. Duty and responsibilities of designated city personnel

2. Actions required to implement NFIP program

3. Implementation and compliance

C. Procedures for Complying with NFIP.

1. The city engineer shall establish through the use of the NFIP panel maps (FIRMs) the areas located within the city that are subject to the requirements of the NFIP.

2. Once affected areas are established, the city planner and/or building official shall notify the affected property owners when any one of the following occurs:

a. Substantial improvement to structures as outlined in the NFIP regulations;

b. Substantial damage to structures by natural disaster; or

c. Substantial damage to structures by fire or flooding.

3. “Substantial improvement” shall be the total of all improvements within a five year time period that equals fifty percent or more of the structure’s market value but not including the land value.

D. Review and Permitting Process. The review and permitting process will be divided into five parts.

1. Development Review. The city planner shall be the lead person in this review process.

a. It shall be identified as early as possible in the planning stage if a proposed project is within the floodplain management area to enable the developer to design to the floodplain requirements.

All applications within the floodplain shall be reviewed by the staff review board (SRB) for compliance with city codes, policies, and procedures as they relate to floodplain management.

b. A staff review board (SRB) shall consist of one member from each of the following departments: fire, police, public works, building, planning, and parks and recreation. The SRB shall meet on a regular basis to review development projects in the floodplain.

c. Projects that do not need planning commission review shall be reviewed by the city planner for conformance with planning regulations, floodplain.

d. Planning commission shall review each project otherwise requiring commission review and if qualified approve the project.

2. Building Permitting Process. The building official shall be the lead person in this review.

a. The building official shall participate in the SRB.

b. Upon initial submission or contact with an owner regarding property improvements where the structure is believed to be within the floodplain, the building official or his designee shall determine if the property is in a floodplain, review the address folder of the project site to determine if any improvements have been done within the last five years, and will determine if the project exceeds the fifty percent threshold.

If the property is found to have had improvements within the preceding five years the total costs of the existing improvements shall be added to the project for the purpose of establishing if the project exceeds the fifty percent threshold.

If no improvements have occurred within the preceding five years only the project costs shall be the sole determining factor for establishment of substantial improvements as required by the floodplains.

c. These floodplain management area regulations do not apply to any properties outside the floodplains.

d. If it has been determined that the project meets the above requirements the developer will be required to design the project to incorporate the requirements of the floodplain management regulations.

3. Construction Inspection of Building Structures.

a. Prior to new construction the property owner shall be required to have the property and structure surveyed and elevations noted on a survey map indicating bench mark, spot elevation locations, spot elevation measurements, date of survey, surveyor name and registration number. This shall occur again prior to final approval to verify conformance with the approved plans and floodplain management requirements. One copy shall be included in the building division address file.

b. Inspection by the building official or designee shall occur at the scheduled intervals beginning with the foundation. At that time the inspector shall verify lowest floor elevation as it relates to elevations established by USGS markers and reference points. Construction found to comply will be allowed to proceed. Construction found to be in non-compliance shall be brought into conformance before being allowed to proceed.

4. Construction Inspection of Public Infrastructure by Public Works.

a. The public works director shall assign project staff to inspect the construction, repair and improvement of public facilities and infrastructure to ensure compliance with relevant floodplain management regulations.

5. Post Disaster Evaluation and Assessment.

a. Post disaster damage assessment and evaluation shall be conducted using forms from FEMA 311 – Guidance on estimating substantial damage. The damage assessment team shall include the building official and another qualified individual who shall evaluate the structures and generate a damage assessment report using FEMA 311 software or most current software.

b. Any structures determined to be substantially damaged shall be evaluated. If damage is found to exceed fifty percent of the structure’s value, the structure shall be brought into conformance with the city’s floodplain management regulations. (Ord. 688, § 1; 1976 Code § 8-10.26).

Chapter 8.50FLOOD DAMAGE PREVENTION

8.50.010 Title.

8.50.020 Definitions.