Protect Coyote Hills

Facts >> Public Safety - Firestorm and Disaster Waiting to Happen?

The Patterson Ranch proposed development puts 520 2-story housing units on land that is subject to the highest intensity of shaking (as rated by US Geological Survey) and high risk of liquefaction (see map below). In addition, the housing units will also be constructed on man-made fill added to the liquefaction-prone land so the structures can be raised above flood level (the site is less than one mile from San Francisco Bay).

Below is a map from U.S. Pipeline and Hazardous Materials Safety Administration that shows the proposed Patterson Ranch development in relation to the second highest risk natural gas transmission pipeline in the Bay Area.

According to the US Geological Survey, “When the ground liquefies, it may lose its ability to support buildings and other structures. Liquefaction during large earthquakes commonly disrupts pipelines and road networks and also may cause buildings to settle and move down slope or toward stream banks. Potentially hazardous areas include those along some of the larger streams, which produce loose young soils that are particularly susceptible to liquefaction . . . . Many regions of man-made fill liquefied in the 1989 Loma Prieta earthquake. The Marina District built on fill in San Francisco suffered some of the worst damage in 1989 (see photos below).”

The first two floors of this San Francisco Marina district apartment sank below ground due to liquefaction. An automobile is crushed under the third story of this building (US Geological Survey).

The buildings may withstand an earthquake—only to become fuel for a major fire that can put Fremont and Union City at risk. 

In liquefaction, underground gas mains and water mains rupture. This is what happened in the Marina District in SF during Loma Prieta. The problem wasn't only collapsed buildings; fires also started from gas main ruptures. And those fires could not be easily extinguished because the water mains had ruptured as well. Long lines of fire hoses had to be laid before the fire department could even start fighting the Marina fire. Magnifying the problem of a potential fire in Coyote Hills are the strong afternoon southeasterly winds coming from the San Francisco Bay less than one mile away.

With the rupture of a gas line in San Bruno in September 2010, an inferno erupted, resulting in 8 deaths and 56 homes destroyed.

Burned apartment complex in San Francisco Marina district (US Geological Survey)

Building in SF Marina District collapsed and an area burned. Note water on the ground from rupture of water mains (US Geological Survey).


If Patterson Ranch were to be built, would there be sufficient beds and emergency services at Washington and Kaiser Hospitals to accommodate a public safety disaster in a development with over 2,000 residents?

This does not include over 1,000 residents at the Pulte development being built across from Coyote Hills. This 15.5-acre property was sold by the Patterson family for $63 million.

NO fire station is included in this proposed massive development; therefore, help is unfortunately not immediately available in the event of a public disaster.

Shouldn’t the city council have responsibility for citizens’ safety?



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