4-1-6: FINDINGS:
The city council of the city of Placerville finds and declares that the additions, modifications and changes made to these codes are necessary for the protection of the public health, safety and welfare due to climatic, geological or topographical conditions. These amendments are authorized under Health And Safety Code sections 18941.5 and 17958 and are identified as follows:
   (A)   Express finding number 1; climatic: The city of Placerville is located approximately forty five (45) miles east of Sacramento and seventy (70) miles west of Lake Tahoe at an average elevation of one thousand eight hundred seventy feet (1,870') above sea level. It is the transition area between the California central valley and the Sierra Nevada Mountains. It experiences a change in precipitation and snowfall from the arid central valley to the deep snow of the mountains. The average annual rainfall is thirty six inches (36"). This rainfall normally occurs from October to April. Hourly rainfall for design purposes is three inches (3") per hour or 0.031 gpm per square foot as established from data in the "El Dorado County Drainage Manual" and nearby jurisdictions. Snow can be expected each winter but usually does not accumulate for an appreciable amount of time. Historically for at least twenty (20) years, the design roof snow load has been twenty (20) pounds per square foot with no reduction allowed.
Climate is one of the greatest impacts to fire behavior and other major emergency events because it cannot be controlled. The drying out of wood building components and wildland fuels in the summer months allows for easy ignition and propagation of fire. Steep, narrow, often congested streets can lead to longer response times for firefighters. Therefore, the fire classification of roof assemblies and roof coverings should be the most restrictive.
Amendments related to climate: CBC section 1505.1.1, 1607A.11.2, 1608A.2.
   (B)   Express finding number 2; geological: The city of Placerville has three (3) dominant east/west ridgelines, which in turn define the principal watersheds, with a series of subwatersheds branching off each major watershed divide. These subridgelines are generally oriented in a north/south direction perpendicular to the primary ridgelines. The secondary ridgelines are located at "regular" intervals approximately one-fourth (1/4) of a mile apart. The moderate to steep slopes, which are characteristic of this topography, have a profound influence on the location of roads and hence the development pattern. There are no identified active earthquake faults in Placerville; however, the inactive Melones Fault does pass through the eastern part of the city, trending in a north/south direction. The city of Placerville is subject to ground tremors from seismic events as the city is located in site class C. Some portions of the city have poor soil conditions that are often expansive in nature. Due to the potential for seismic activity, a need exists for more restrictive design criteria.
Amendments related to geological conditions: CBC section 1607A.11.2, 1608A.2.
   (C)   Express finding number 3; topographical: The city of Placerville is located in the transition between the California central valley and the Sierra Nevada Mountains. Three (3) biophysical gradients are apparent: a transition from central valley grassland vegetation, to mixed needleleaf and broadleaf forests, to Sierra evergreen forests. The threat to Placerville from wildland fires is relatively high due to the dense vegetative cover and steeply sloping lands. Therefore, a need exists for additional fire protection measures.
Amendments relating to topographical conditions: CBC section 1505.1.1.
   (Ord. 1623, 2-12-2008)