16.02.040 Findings and determination.

As permitted in Health and Safety Code Section 17958.7, the city of American Canyon finds and determines the local amendments to the 2022 California Building Code are either administrative in nature or reasonably necessary to protect the health, safety and general welfare of the public due to local climatic, geological or topographical conditions. Those findings are as follows:

Express Finding Number 1: Climatic. The city is located in a climatic zone with precipitation ranging from fifteen to twenty-six inches per year. Ninety-five percent of precipitation falls during the months of November through April, leaving a dry period of approximately six months each year. Relative humidity remains moderate most of the time. High temperatures in the summer average in the mid-eighty degrees Fahrenheit and in the winter in the mid-fifty degrees Fahrenheit. Prevailing winds in the area are common with gusts up to thirty-five miles per hour. These climatic conditions, along with our topography, necessitate a greater requirement for fire-sprinklers in residential construction, a minimum Class A roof covering and adequate spark arrestors.

Express Finding Number 2: Geological. The city is located in Seismic Design Category D, which is indicative of high seismic vulnerability. The West Napa fault is documented to be present in our city. The area includes various soil conditions and areas with significant movement potential. Buildings and other structures in Seismic Design Category D can experience major seismic damage. These geological conditions necessitate the prohibition of gypsum as a lateral-resisting building element, and the restriction of Portland cement plaster as a lateral-resisting building element to one-story structures of R-3 and U-1 occupancies.

Express Finding Number 3: Topographical. Areas of highly combustible dry grasses, weeds, brush and trees adjacent to structures are common throughout the city. Above-ground electrical power transmission lines are suspended through trees and above large areas of dry vegetation. The arrangement of man-made features around many buildings greatly limits any approach to all but one side of a building. The area immediately adjacent to the eastern border of the city has been classified as high and very high fire severity zones under the Fire and Resource Assessment Program of the California Department of Forestry and Fire Protection. These topographical conditions, along with our climate, necessitate a greater requirement for fire-sprinklers in residential construction, a minimum Class A roof covering and adequate spark arrestors.