To the extent that any of the provisions of this chapter constitute changes or modifications in the requirements contained in Health and Safety Code Section 17922, the Larkspur City Council does hereby find that such changes and modifications are reasonably necessary because of local conditions prevailing within the City of Larkspur. A description of said local conditions is hereinafter set forth.

1. Climatic.

a. The weather patterns within the City of Larkspur are considered to be moderately affected by the Pacific Ocean and the San Francisco Bay, which extends the year-round growing season of vegetation. The normal year’s rainfall is approximately 28 inches, while the summer condition, with its prevalent Pacific high cell, creates the morning and late afternoon fog normally associated with the San Francisco Bay.

b. Humidity generally ranges from 50% during the daytime to 86% at night. It drops to 20% and lower during the summer months.

c. While normal temperatures usually do not exceed 75-80 degrees during the summer months, little or no rain falls during the period between April and November. This combination often creates hazardous fuel conditions in the City. Drying winds in the summer and fall months reduce fuel moisture and relative humidity to the minimum levels, thereby creating ideal fire weather conditions. The normal afternoon winds that precede the fog can move a fire quickly in the hillside and open space areas of the City.

d. Prevailing winds are from the northwest. However, winds are experienced from virtually every direction at one time or another due to the area's topography and location. Velocities are generally in the 5-15 mph range, gusting to 20-30 mph, particularly during the summer months. Extreme winds up to 50 mph have been known to occur.

e. Because of climatic conditions, the County of Marin has experienced water rationing in recent years, including a mandatory 35 percent reduction in 1989 and 20% in 2015. Water shortages can be expected in future years due to limited storage capacities in Marin, increased domestic consumption and weather patterns that reduce the already minimal annual rainfall. While sound management of the water resources is possible, actual demands on an already stressed water supply can most assuredly be predicted.

2. Geologic.

a. The City of Larkspur is geologically mixed with three classifications of rock: igneous, metamorphic and sedimentary. The outstanding material is volcanic in origin with ridges of serpentine reaching in excess of 700 feet in elevation.

b. Much of the City is characterized by precipitous hilly areas where escape opportunities from residential structures are limited to one side of the home only. The steepness and uneven nature of the land often hinders, and sometimes prevents, the erecting of rescue ladders at the side of a home on a hillside parcel.

c. Seismic activity within the City occurs yearly with little or no damage, although a real potential does exist with the City situated between two active faults: the San Andreas and Hayward faults.

d. Landslides have also been experienced in the City in recent years. While stabilization of hillsides can sometimes be achieved, heavy rainfalls have caused failures. These slides can close roadways, making accessibility to many locations in the City impossible until properly cleared.

3. Topographic.

a. The City of Larkspur is accessible from the outside by one primary thoroughfare on the east side and three on the west side. Speed limits of 25 miles per hour, by virtue of the narrow and twisting configuration of the roads, do not allow quick responses to emergencies. The Highway 101 corridor goes directly through the City and an overpass that may or may not withstand an earthquake presents another problem.

b. Vehicular access within the City is affected by steep, hilly terrain and many secondary ridgelines. Many streets are narrow and winding, restricting the speed at which fire apparatus may safely respond and also increasing the time-lapse between fire detection and apparatus arrival, during which time a family will face the fire or other emergency on their own. The City has many dead- end streets, and in Madrone Canyon, there is one main access route in or out of the area. Dead-end streets can restrict the ease of relocating fire and rescue equipment from one location to another, even though actual separating distance between two areas may be minimal. In addition to restricting access routes for fire apparatus, the dead-end streets also limit egress opportunities for residents.

c. Many of the commercial buildings in Larkspur were largely built long before present code requirements existed. Consequently, many of these structures do not meet even minimal standards for fire protection and life safety. Wood frame construction of older buildings, especially those in mountainous areas, creates an adverse exposure problem, not only in being easily ignited by an adjacent structure fire, but also in contributing to the extension of fire to other buildings through radiation, actual physical heat conduction and flying embers. Fire history in the City has shown flying embers will start secondary fires after blowing in the air.

d. The buildings in Madrone Canyon, many of which were constructed 50 or more years ago, are serviced by minimal water main sizes. The lack of adequate water supply in this area, along with winding streets, creates a unique fire problem. The generalized water shortage in Marin County results in occasional inadequate water volume and pressure for firefighting purposes in certain areas of the City.

Conclusion: Local climatic, geographic and topographic conditions impact fire prevention efforts, and the frequency, spread, acceleration, intensity and size of fire involving buildings in this community. Further, they impact potential damage to all structures from earthquake and subsequent fire. Therefore, it is found to be reasonably necessary that the California Fire Code and the State Building Standards Code be changed or modified to mitigate the effects of the above conditions.

The following table lists the California Fire Code sections that have been modified pursuant to Larkspur Municipal Code Section 14.04.110 and the corresponding local climatic, geological, and topographical condition findings that necessitate each amendment, addition, or deletion.

CA Fire Code Section No.	Local Condition Finding
202	1c, 2a, 2b, 2d, 3a, 3b
302.1	2b, 2d, 3a, 3b, 3c, 3d
324	2b, 2d, 3a, 3b, 3c, 3d
401.1.1	2c, 2d, 3a, 3b, 3c, 3d
401.3.2.1-401.3.2.2	2a, 2c, 2d, 3a, 3b, 3c
402.1	2b, 2d, 3a, 3b, 3c, 3d
403.1.1	2a, 2b, 2c, 2d, 3a, 2g
403.9.1.4	2a, 2b, 2c, 2d, 2e, 2g
502.1	2a, 2c, 2d, 2e, 2f, 2g
503.1	2a, 2c, 2d, 2e, 2f, 2g
503.1.4	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.1.5-503.1.5.3	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.2.1	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.2.6.1	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.4	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.4.2	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.6.1	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.6.2	2a, 2c, 2d, 3a, 3b, 3c, 3d
503.6.3	2a, 2c, 2d, 3a, 3b, 3c, 3d
507.5.1	2a, 2c, 2d, 3a, 3b, 3c, 3d
507.5.1.1	2a, 2c, 2d, 3a, 3b, 3c, 3d
507.5.7	2a, 2c, 2d, 3a, 3b, 3c, 3d
510.1	2a, 2b, 2c, 2d, 3d
901.7	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
902.1	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
903.2 – 903.2.4	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
903.3.9	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
903.6.1	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
906.11	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
907.2.13.1.2	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
907.6.6	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
907.8.5	2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
918-918.3	1b, 1c, 1d, 1e, 2c, 2d
1208-1208.8	2b, 2d, 3a, 3b, 3c, 3d
3314.3	2a, 2b, 2c, 2d, 3d
3315.3	2a, 2b, 2c, 2d, 3d
3315.4	2a, 2b, 2c, 2d, 3d
4902.1	1a, 1b, 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
4903.2.1.1-4903.2.2	1a, 1b, 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
4906.2-4906.4.2.1	1a, 1b, 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
4907.2 – 4907.4	1a, 1b, 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
4907.5	1a, 1b, 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d
5608.1.2 – 5608.2	2a, 2c, 2d, 3a, 3b, 3c, 3d
Chapter 80	1a, 1b, 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d