This chapter applies to all areas of special flood hazards within the jurisdiction of the Town of Danville, California. (Ord. #133, §8-4811; Ord. #2002-02, §2)

   The areas of special flood hazard identified by the Federal Insurance Administration (FIA) of the Federal Emergency Agency (FEMA) in the Flood Insurance Study (FIS) dated September 7, 2001 and accompanying Flood Insurance Rate Maps (FIRMs) and Flood Boundary and Floodway Maps (FBFMs), dated September 7, 2000, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this ordinance. This FIS and attendant mapping is the minimum area of applicability of this ordinance and may be supplemented by studies for other areas which allow implementation of this ordinance and which are recommended to the Town of Danville by the Development Services Director. The study, FIRMs and FBFMs are on file at 510 La Gonda Way, Danville, California. (Ord. #133, §8-4812; Ord. #2002-02, §2)

   No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this section and other applicable regulations. Violations of the provisions of this section 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 Town Council from taking such lawful action as is necessary to prevent or remedy any violation. (Ord. #133, §8-4813; Ord. #2002-02, §2)

   This section is not intended to repeal, abrogate, or impair existing easements, covenants, or deed restrictions. However, where this section and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. (Ord. #133, §8-4814; Ord. #2002-02, §2)

   In the interpretation and application of this section, 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, #133, §8-4815; Ord. #2002-02, §2)

   The degree of flood protection required by this section 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 section 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 section shall not create liability on the part of the Town of Danville, any officer or employee thereof, the State of California, the Federal Insurance Administration, or the Federal Emergency Management Agency, for flood damage that results from reliance on this section or an administrative decision made under it. (Ord. #133, §8-4816; Ord. #2002-02, §2)

   This section and the various parts thereof are hereby declared to be severable. Should any subsection of this section be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the section as a whole, or any portion thereof other than the subsection so declared to be unconstitutional or invalid. (Ord. #133, §8-4817; Ord. #2002-02, §2)

   A Development Permit must be obtained before construction or development begins within any area of special flood hazard established in subsection 32-117.12. Application for a Development Permit shall be made on forms furnished by the Development Services Director and may include, but not be limited to: plans in duplicate drawn to scale showing the nature, location, dimensions, and elevation for the area in question; existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing. Specifically, the following information is required:

   a.   Site plan, including, but not limited to:

      1.   For all proposed structures, spot ground elevations at building corners and twenty (20) foot or smaller intervals along the foundation footprint, or one (1) foot contour elevations throughout the building site; and

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

      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; and

      2.   For a crawl space foundation, location and total net area of foundation openings as required in 32-117.34.c of this section 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 (95%) percent using the Standard Proctor Test method);

   c.   Proposed elevation in relation to mean sea level to which any nonresidential structure will be floodproofed, as required in 32-117.34.b of this section and FEMA Technical Bulletin TB 3-93; and

   d.   All appropriate certifications listed in 32-117.23.e of this section; and

   e.   Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. (Ord. 133, §8-4821; Ord. #2002-02, §2)

   The Development Services Director is appointed to administer and implement this section by granting or denying development permit applications in accordance with its provisions. (Ord. #133, §8-4822; Ord. #2002-02, §2)

   The duties and responsibilities of the Development Services Director include, but are not limited to, the following:

   a.   Development Permit Review. The Development Services Director shall review all development permits to determine that:

      1.   The permit requirements of this section are 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 purposes of this section, "adversely affect" means that the cumulative effect of the proposed development when combined with all other existing and anticipated development will not increase the water surface elevation of the base flood more than one (1) foot at any point.

   b.   Use of Other Base Flood Data. When base flood elevation data have not been provided in accordance with subsection 32-117.12, Basis for Establishing the Areas of Special Flood Hazard, the Development Services Director 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 Division 4 of this section. Any such information shall be submitted to the Town Council of the Town of Danville for adoption; or

   c.   If no base flood elevation data is available a base flood 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 (100-year) Flood Elevations" dated July 1995 in order to administer Division 4:

      1.   Simplified method:

         (a)   One hundred (100) year or base flood discharge shall be obtained using the appropriate regression equation found in a U.S. Geological Survey publication, or the discharge drainage area method; and

         (b)   Base flood elevation shall be obtained using the Quick-2 computer program developed by FEMA; or

      2.   Detailed method:

         (a)   One hundred (100) year or base flood discharge shall be obtained using the U.S. Army Corp of Engineers' HEC-HMS computer program; and

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

   d.   Notification of Other Agencies. In alteration or relocation of a watercourse:

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

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

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

   e.   Information to be Obtained and Maintained. The Development Services Director shall obtain and maintain for public inspection and make available as needed the following:

      1.   The certification required in section 32-117.34.a and Section 32-117.38 (flood elevations);

      2.   The floodproofing certification required in section 32-117.34.b (elevation or floodproofing of nonresidential structures);

      3.   The certification required in section 32-117.34.c.1 or 32-117.34.c.2 (wet floodproofing standard);

      4.   The certification required in section 32-117.37.b (subdivision standards);

      5.   The certification required in section 32-117.39.a (floodway encroachments).

   f.   Alteration of Watercourses. Whenever a watercourse is to be altered or relocated, the Development Services Director shall:

      1.   Notify adjacent communities and the California Department of Water Resources prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration; and

      2.   Require that the flood carrying capacity of the altered or relocated portion of said watercourse be maintained.

   g.   Interpretation of FIRM Boundaries. The Development Services Director shall make interpretations where needed as to the exact location of the boundaries of the areas of special flood hazards (for example, 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 or 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 Division 5 of this section.

   h.   Remedy Violations. The Development Services Director shall take action to remedy violations of this section as specified in subsection 32-117.13.

   i.   Appeals. The Town of Danville shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Development Services Director in the enforcement or administration of this section. (Ord. #133, §8-4823; Ord. #2002-02, §2)

   The standards set forth in this division are required in all areas of special flood hazards. (Ord. #133, §8-4831; Ord. #2002-02, §2)

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

   b.   All manufactured homes shall meet the anchoring standards of subsection 32-117.38.b. (Ord. #133, §8-4832; Ord. #2002-02, §2)

   All new construction and substantial improvements shall be constructed:

   a.   With flood resistant materials as specified in FEMA Technical Bulletin TB 2-93, and utility equipment resistant to flood damage;

   b.   Using methods and practices that minimize flood damage;

   c.   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. #133, §8-4833; Ord. #2002-02, §2)

   (See definitions for "basement," "lowest floor," "new construction," "substantial damage" and "substantial improvement").

   a.   Residential construction, new or substantial improvement shall have the lowest floor, including basement, elevated to or above one (1) foot above the base flood elevation. Base flood elevation shall be determined by one (1) of the methods in 32-117.23.b of this section.

   b.   Nonresidential construction shall either be elevated in conformance with subsection (a) or together with attendant utility and sanitary facilities:

      1.   Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;

      2.   Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

      3.   Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifications shall be provided to the Development Services Director.

   c.   All new construction and substantial improvements with fully enclosed areas below the lowest floor (excluding basements) that are usable solely for parking of vehicles, building access or storage, and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement shall follow the guidelines in FEMA Technical Bulletins TB 10-93 and TB 7-93, and must exceed the following minimum criteria:

      1.   Have a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one (1) 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

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

   d.   Manufactured homes shall meet the standards in this section and also the standards in subsection 32-117.38.

   e.   Upon the completion of new structures or substantial improvements in Zone A, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, and verified by the community building inspector to be properly elevated. Such certification and verification shall be provided to the Development Services Director. (Ord. #133, §8-4834; Ord. #2002-02, §2)

   a.   The storage or processing of materials that are in time of flooding buoyant, flammable, explosive, or could be injurious to human, animal or plant life is prohibited.

   b.   Storage of other material or equipment may be allowed if not subject to major damage by floods and firmly anchored to prevent flotation or if readily removable from the area within the time available after flood warning. (Ord. #133, §8-4835; Ord. #2002-02, §2)

   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. (Ord. #133, §8-4836; Ord. #2002-02, §2)

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

   b.   All final subdivision plans will provide the elevation of proposed structures and pads. If the site is filled above the base flood, the final pad elevation shall be certified by a registered professional engineer or surveyor and shall be provided to the Development Services Director.

   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 subdivision proposals shall provide adequate drainage to reduce exposure to flood hazards. (Ord, #133, §8-4837; Ord. #2002-02, §2)

   a.   All new and substantially improved manufactured homes and additions to manufactured homes within Zone A on sites located:

      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; or

      4.   In an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred "substantial damage" as the result of a flood shall be elevated so that the lowest floor is at or above one (1) foot above the base flood elevation and be securely anchored to a permanent foundation system to resist flotation, collapse or lateral movement.

   b.   All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1-30, AH, AE, V1-30, V, and VE on the community's Flood Insurance Rate Map that are not subject to the provisions above shall be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement, and be elevated so that either the:

      1.   Lowest floor of the manufactured home is at or above one (1) foot above the base flood elevation; or

      2.   The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade.

   c.   Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, and verified by the community building inspector to be properly elevated. Such certification and verification shall be provided to the Development Services Director. (Ord. #133, §8-4838; Ord. #2002-02, §2)

   Areas designated as floodways are located within areas of special flood hazard established in subsection 32-117.12. 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.   Encroachment, including fill, new construction, substantial improvements, and other development, is prohibited, unless certification by a registered professional engineer or architect is provided demonstrating that the encroachment shall not result in any increase in flood levels during the occurrence of the base flood discharge.

   b.   If paragraph a. is satisfied, all new construction, substantial improvements and other proposed new development shall comply with all applicable flood hazard reduction provisions of this division. (Ord. #133, §8-4839; Ord. #2002-02, §2)

   a.   The Planning Commission shall hear and decide appeals and requests for flood hazard variances from the requirements of this section.

   b.   The Planning Commission shall hear and decide appeals when it is alleged there is an error in a requirement, decision or determination made by the Development Services Director in the enforcement or administration of this section.

   c.   The decision of the Planning Commission may be appealed to the Town Council.

   d.   The time and manner for taking an appeal is as provided in Section 30-7. (Ord. #133, §8-4241; Ord. #2002-02, §2)

   In considering an application for a flood hazard variance under this section, the reviewing body shall consider all the technical evaluations, all relevant factors, standards specified in other sections of the Municipal Code, and:

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

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

   c.   The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;

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

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

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

   g.   The relationship of the proposed use to the comprehensive plan and flood plain management program for that area;

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

   i.   The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site;

   j.   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 system, and streets and bridges; and

   k.   The necessity to the facility of a waterfront location, where applicable. (Ord. #133, §8-4242; Ord. #2002-02, §2)

   a.   A flood hazard variance may be issued for new construction and substantial improvements to be erected on a lot of one-half (1/2) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing the standards in subsection 32-117.42 have been fully considered. As the lot size increases beyond the one-half (1/2) acre, the technical justification required for issuing the variance increases.

   b.   Upon consideration of the factors of subsection 32-117.42 and the purposes of this section, the Planning Commission may attach such conditions to the granting of flood hazard variances as it considers necessary to further the purposes of this section.

   c.   The Director of Development Services shall maintain the records of appeal actions and report any flood hazard variances to the Federal Insurance Administration upon request. (Ord. #133, §8-4243; Ord. #2002-02, §2)

   a.   A flood hazard variance may be issued for the reconstruction, rehabilitation or restoration of a structure listed on the National Register of Historic Places or the State Inventory of Historic Places without regard to the procedures set forth in the remainder of this subsection.

   b.   A flood hazard variance shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.

   c.   A flood hazard variance shall only be issued upon a determination that the flood hazard variance is the minimum necessary, considering the flood hazard, to afford relief. (Ord. #133, §8-4244; Ord. #2002-02, §2)

   a.   A flood hazard variance shall only be issued upon:

      1.   A showing of good and sufficient cause;

      2.   A determination that failure to grant the flood hazard variance would result in exceptional hardship to the applicant; and

      3.   A determination that the granting of a flood hazard variance will not result in increased flood heights, additional threats to public safety or extraordinary public expense; create nuisances; cause fraud on or victimization of the public; or conflict with existing local laws or ordinances.

   b.   Flood hazard variances may be issued for new construction and substantial improvements and for other development necessary for the conduct of a functionally dependent use provided that the provisions of this subsection and subsection 32-117.44 are satisfied and that the structure or other development is protected by methods that minimize flood damages during the base flood and create no additional threats to public safety. (Ord. #133, §8-4245; Ord. #2002-02, §2)

   a.   An applicant to whom a flood hazard variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the regulatory flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation.

   b.   A copy of the notice shall be recorded by the Town Clerk in the office of the Contra Costa County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land. (Ord. #133, §8-4246; Ord. #2002-02, §2)