10.10A.020 Scope and application

A. Application. The provisions of this chapter shall apply to all lands in the city located in any area designated as a sensitive lands district on the city’s official maps contained in Appendix A of this ordinance as amended from time to time. All approved subdivision plats that lie wholly or partially in a sensitive lands district shall be recorded with such designation shown on the official plat. B. Supplemental and Conflicting Provisions. Unless otherwise specifically provided, the regulations contained in this chapter are in addition to the standards applicable to the underlying zones, or overlay zones, provided elsewhere in this title or any other applicable title, code, ordinance or law. In the event of conflict between the standards, guidelines and criteria of this chapter and the requirements of the underlying zoning district, the city’s subdivision ordinance or any other requirements of this code, the more restrictive provision shall apply. C. Geologic hazard studies. Project developers and their consultants shall present the results of geologic hazard studies in compliance with this chapter and its appendices. The standards set forth in the appendices to this chapter are the city’s minimum requirements, but may be made more stringent, in specific, fact-sensitive circumstances, by the DRC based on recommendations of the city engineer or city geologist if evidence becomes available that suggests more stringent requirements are appropriate. In addition, the appendices shall not supersede other more stringent requirements that may be required by other regulatory agencies or governmental entities that have jurisdiction. D. Appendix A. Appendix A presents study area maps reflecting geological, hydrologic, infrastructure and other natural and man-made hazard concerns, as well as supplemental maps pertaining to development in the city’s sensitive lands districts. The maps incorporate data obtained from numerous publications, previous geologic hazard studies and other expert sources such as FEMA, UGS, USGS, AGRC, etc. Updated versions of the maps will be added as they become available. E. Appendix B. Appendix B presents the minimum standards for surface fault rupture hazard studies conducted in the city and describes the accepted minimum requirements for planning, conducting and reporting the results of surface fault rupture hazard studies. Site-specific surface fault rupture hazard studies performed by qualified engineering geologists shall be required prior to developing projects located in the Surface Fault Rupture Hazard Study Area as delineated on Map 1 in Appendix A of this chapter. The information contained in Appendix B was compiled from numerous published and unpublished sources and presents the current standard of care for surface fault rupture hazard studies in the city. If due to additional evidence a surface fault rupture hazard becomes known or suspected in an area subject to a development application, which area is not depicted on the Surface Fault Rupture Hazard Study Area Map, the DRC shall require the developer to submit applicable studies as recommended by the city engineer and the city geologist and the process outlined in this chapter shall be followed. F. Appendix C. Appendix C presents the minimum standards for slope stability and landslide hazard studies conducted in the city and describes the accepted minimum requirements for planning, conducting and reporting the results of slope stability and landslide hazard studies. Site-specific slope stability and landslide hazard studies performed by qualified engineering geologists and geotechnical engineers shall be required prior to developing projects located in the Slope Stability and Landslide Hazard Study Area as delineated on Map 2 in Appendix A of this chapter. The information contained in Appendix C was compiled from numerous published and unpublished sources and presents the current standard of care for slope stability and landslide hazard studies in the city. If due to additional evidence a slope stability and/or landslide hazard becomes known or suspected in an area subject to a development application, which area is not depicted on the Slope Stability and Landslide Hazard Study Area Map, the DRC shall require the developer to submit applicable studies as recommended by the city engineer and the city geologist and the process outlined in this chapter shall be followed. At a minimum, a special study of slope stability will be required in the following instance: (1) Site-specific slope stability analysis for all development in zones with moderate to very high hazard of landslides (Map 2). G. Appendix D. Appendix D presents the minimum standards for liquefaction hazard studies conducted in the city and describes the accepted minimum requirements for planning, conducting and reporting the results of liquefaction hazard studies. Site-specific liquefaction hazard studies performed by qualified engineering geologists and geotechnical engineers shall be required prior to developing projects located in the Liquefaction Hazard Study Area as delineated on Map 3 in Appendix A of this chapter. The information contained in Appendix D was compiled from numerous published and unpublished sources and presents the current standard of care for liquefaction hazard studies in the city. If due to additional evidence a liquefaction hazard becomes known or suspected in an area subject to a development application, which area is not depicted on the Liquefaction Hazard Study Area Map, the DRC shall require the developer to submit applicable studies as recommended by the city engineer and the city geologist and the process outlined in this chapter shall be followed. At a minimum, a special study of liquefaction hazard will be required in the following instances: (1) Require site-specific liquefaction hazard analysis in zones of moderate to high liquefaction potential (Map 3) for the following IBC occupancy groups: Assembly Group A, Business Group B, Factory Group F-1, Educational Group E, High-Hazard Group H, Institutional Group I, and Residential Groups R-1, R-2, and R-4. H. Appendix E. Appendix E presents the minimum standards for debris flow/alluvial fan flooding hazard studies conducted in the city and describes the accepted minimum requirements for planning, conducting and reporting the results of debris flow/alluvial fan flooding hazard studies. Site-specific debris flow/alluvial fan flooding hazard studies performed by qualified engineering geologists and geotechnical engineers shall be required prior to developing projects located in the Debris Flow/alluvial fan flooding Hazard Study Area as delineated on Map 4 in Appendix A of this chapter. The information contained in Appendix E was compiled from numerous published and unpublished sources and presents the current standard of care for debris flow/alluvial fan flooding hazard studies in the city. If due to additional evidence a debris flow/alluvial fan flooding hazard becomes known or suspected in an area subject to a development application, which area is not depicted on the Debris Flow/Alluvial Fan Flooding Hazard Study Area Map, the DRC shall require the developer to submit applicable studies as recommended by the city engineer and the city geologist and the process outlined in this chapter shall be followed. At a minimum, a special study of debris flow/alluvial fan flooding hazard will be required in the following instances: (1) Site-specific debris flow/alluvial fan flooding hazard analysis for all development in zones with moderate to high debris flow/alluvial fan flooding hazard (Map 4). I. Appendix F. Appendix F presents the minimum standards for rockfall hazard studies conducted in the city and describes the accepted minimum requirements for planning, conducting and reporting the results of rockfall hazard studies. Site-specific rockfall hazard studies performed by qualified engineering geologists and geotechnical engineers shall be required prior to developing projects located in the Rockfall Hazard Study Area as delineated on Map 5 in Appendix A of this chapter. The information contained in Appendix F was compiled from numerous published and unpublished sources and presents the current standard of care for rockfall hazard studies in the city. If due to additional evidence a rockfall hazard becomes known or suspected in an area subject to a development application, which area is not depicted on the Rockfall Hazard Study Area Map, the DRC shall require the developer to submit applicable studies as recommended by the city engineer and the city geologist and the process outlined in this chapter shall be followed. At a minimum, a special study of rockfall hazard will be required in the following instance: (1) Site-specific rockfall hazard analysis for all development in zones with moderate to high rockfall hazard (Map 5). J. Appendix G. Appendix G presents the source protection zones that require special regulations for the storage, handling, use or production of hazardous or toxic substances in order to protect, preserve and maintain existing and future public drinking water sources. The source protection zones are generally located upgradient of wells or near proposed points of diversion for the development of groundwater. Groundwater recharge zones are located in permeable and/or sensitive areas that have a critical impact on the groundwater quality and quantity of supply. The protection of source protection zones and groundwater recharge areas is essential to the health, safety and welfare of city residents and visitors. At a minimum, observations of excavations will be required in the following instance: (1) Observations of excavations by qualified engineers and/or geologists for all development within active fault special study zones (Map 1), areas with moderate to very high slope stability hazard (Map 2), areas with moderate to high liquefaction potential (Map 3), and areas with groundwater at depths of less than ten feet (Map 11). (2) Observations of excavations by qualified engineers and/or geologists for all development, even outside of the zones specified above, for the following IBC occupancy groups: Assembly Group A, Educational Group E, High-Hazard Group H, Institutional Group I, and Residential Groups R-1, R-2, and R-4. K. Appendix H. Appendix H presents the foundation excavation observations that are required for all new structures or additions that are built in the city. The DRC shall require the owner to submit a foundation excavation observation report, prepared in accordance with the process outlined in this chapter, prior to the construction of any structural footing or foundation for all buildings in the city. L. Appendix I. Appendix I presents the riparian corridor and watershed protections adopted to minimize erosion and stabilize stream banks, improve water quality, preserve fish and wildlife habitat, regulate stream temperatures, reduce potential for flood damage, preserve natural aesthetic value of streams and protect the prime groundwater recharge areas of the city. These requirements are intended to provide protection for above-ground streams, stream corridors and recharge areas. Where streams flow through areas that are already developed, the riparian corridor and watershed protection requirements are intended to achieve a reasonable balance between natural streams and developed land uses.