Chapter 16.507 — NATURAL HAZARD REDUCTION

The purpose of this chapter is to implement general plan policies and comply with applicable state requirements to protect public safety by identifying natural hazards and reducing their risk. More specifically, these regulations are intended to address the risks posed by wildfires, flooding, geotechnical hazards and seismic events, and projected sea level rise by:

A.

Maintaining up-to-date information identifying areas with high risk from wildfires, floods, earthquakes, and inundation from sea-level rise;

B.

Requiring development in areas at risk from natural hazards to consider the impacts of their proposal and incorporate measures that will reduce threats to public safety;

C.

Referring proposed plans and projects in risk areas to state and local environmental management agencies for review and comment.

The following requirements apply to all development in areas that General Plan Map NBE-4 identifies as moderate or high wildfire risk areas:

A.

Applications for development in moderate or high wildfire risk areas shall be submitted to the fire prevention department for review and recommendation of mitigation measures including specification of building and roof materials, firebreaks, fire resistant landscape materials, access roads to open as, internal fire protection systems and adequate water supply.

B.

All areas within one hundred feet of combustible structures in the moderate and high wildfire risk areas shall be kept clear of flammable vegetation.

All development proposed in areas identified by the Federal Insurance Administration's "Flood Insurance Study for the city of Vallejo" shall comply with the following requirements:

A.

The director shall refer applications to the Vallejo Flood and Wastewater District (VFWW) for review and comment and require applicants to revise projects as necessary in response to VFWW recommendations;

B.

Applicants proposing development, grading, and land modification activities that may adversely affect the local drainage system or create erosion may be required to submit engineering reports, subject to peer review at the applicants expense, recommending measures that should be incorporated to mitigate such impacts;

C.

New and modified structures in the one hundred-year floodplain are required to comply with the city's flood management regulations including elevating building pads above flooding levels and other flood-proofing measures.

D.

The construction of permanent structures in designated floodways is prohibited.

E.

Development in areas identified as vulnerable to a projected fifty-five-inch sea level rise by 2100 in General Plan Map NBE-6 or the city's adopted climate action plan, whichever is more restrictive is subject to environmental review for the purpose of assessing potential impacts of inundation and identifying measures to mitigate such effects.

All development proposed in areas the city has designated as geotechnical hazard risk zoning districts B, C, and D on the Geotechnical Land Use Capability Map, Plate 2, Seismic Safety Element shall comply with the requirements of this chapter.

A.

Use Restrictions. The use of land within areas identified as geotechnical hazard risk zones shall comply with the requirements of Table 16.507-A.

TABLE 16.507-A: USE RESTRICTIONS BY HAZARD RISK ZONE

Geologic Report Required. All applications to develop land for uses identified as being permitted but subject to geotechnical hazards shall include a soil and geologic report prepared by a registered soil engineer and registered geologist certified in engineering geology to assess geologic hazards, subject to a peer review at the applicant's expense.

a.

The soils and geologic report shall be directed to determining the presence or absence of an active known fault on the development site and to determining appropriate structural design recommendations. Subsurface exploration may be required if a lack of distinguishable fault features in the vicinity prevents the geologist from determining by a site examination, review of available aerial photographs, or by other means that the fault trace does or does not underlie or exist within fifty feet of any structures proposed for the development site.

b.

A more detailed and extensive investigation and report by the geologist may be required (as evidence to the absence of a known active fault trace) for applications proposing development of Group A, E, I, H, and R-1 occupancies, and B occupancies as set forth in the Uniform Building Code) over one story in height.

c.

The geologic report may be waived, with the approval of the state geologist, if the city determines that no active known fault exists on the development site or, in the case of applications for development containing a maximum of two dwelling units, that sufficient information regarding the site is available from previous reports filed concerning the same development area.

2.

Review of Geologic Report. If the geologic report indicates that the proposed use is not subject to geotechnical hazards, the use may not be denied based on geologic findings, but subject to any special conditions, noted in the report. These conditions shall be attached to the application and be applicable to the proposed use. If the geologic report indicates that geotechnical problems may exist for the proposed use, the applicant shall be required to obtain a major use permit as prescribed in Chapter 16.606, Minor and Major Use Permits; except that when identified problems are so severe, the proposed use may be prohibited.

3.

Construction Limitations. As per the provisions of the Alquist-Priolo Act, no building or structure to be used for human occupancy may be constructed over or within fifty feet of the trace of a known active fault. For the purpose of these regulations, a building or structure to be used for human occupancy is one that is regularly, habitually, or primarily occupied by humans. Buildings and structures shall be designed to resist the earthquake forces prescribed by the Uniform Building Code and to incorporate the design recommendations contained in the soils and geologic report required.

B.

Independent Evaluation Requirement. In addition to the requirements of this section, the city shall require an independent evaluation of any of the soils and geologic reports submitted by the applicant for certain uses to be located in risk zone D as described in this section. The city may establish a fee to cover the costs of the required evaluation.

The provisions of this chapter shall not apply to:

A.

Buildings and structures not intended to be used for human occupancy;

B.

Alterations or repairs to an existing structure provided that the aggregated value of the work performed does not adversely affect the structural integrity of the existing structure as required by the Building Code;

C.

A single-unit wood frame dwelling not exceeding two stories in height, which is built or located as part of a development of less than four such dwellings;

D.

Mobile homes as part of a mobile home park; and

E.

Decorative walls, fences, and minor work of a similar nature.

Chapter 16.508 - OFF-STREET PARKING AND LOADING