Water Transmission Hazard Mitigation Project: Isolation Valves Installation

    Isolation ValveThere is a 63 percent probability of a magnitude 6.7 earthquake in San Francisco Bay Region from 2007 to 2036.  We are working to secure our future water supply by installing 14 isolation valves throughout our more than 83 miles of underground aqueduct.  These isolation valves will provide greater control of potential pipeline breaks due to a seismic event, and allow our dedicated staff the ability to provide safe, reliable drinking water.   

    The Sonoma County Water Agency (Water Agency) has been awarded a $1,930,181 grant from the Federal Emergency Management Agency (FEMA) to install 14 isolation valves throughout the water transmission system. This work will increase the Water Agency’s operational capability to restore a reliable water supply, minimize risk to life and property, maximize the number of residents who can remain in service, and prevent water quality impairment that could likely result from a transmission pipeline failure immediately following a major seismic event.

    The Water Agency has prepared a Local Hazard Mitigation Plan (Local Plan) to ensure that it could provide an uninterrupted supply of clean drinking water and water for fire-fighting and to minimize the potential for loss of life and property damage following a major natural disaster.  A Local Plan approved by FEMA is a pre-requisite for FEMA and other sources of funding, and must be updated, re-submitted, and approved by FEMA every five years. On January 8, 2008, the Board of Directors adopted the Water Agency’s Local Plan, and on December 11, 2012, the Board of Directors adopted the 2012 Local Plan Update.  The Local Plan identifies various projects as having the greatest importance to the community served by the Water Agency. 

    In 2009, the Water Agency submitted an application for funding of the Isolation Valves Replacement Project (Project). The Project will install 14 isolation valves throughout more than 83 miles of the water transmission system to reduce the risk of adverse impacts of pipeline failure/rupture due to ground shaking, fault rupture, liquefaction, and lateral spread caused by seismic events.  Valves will be installed at locations that would increase the Water Agency’s operational capability to restore a reliable water supply, minimize risk to life and property, maximize the number of residents who can remain in service, and prevent water quality impairment that could likely result from a transmission pipeline failure immediately following a major seismic event. The estimated project cost is $3,667,740 with total offsetting grant revenue of $1,930,181. On May 9 2014, the Water Agency received notification letter from California Office of Emergency Services that FEMA had formally approved the Water Agency’s Isolation Valves Replacement Project application in the amount of $1,930,181. Construction began in October 2016.

    Isolation Valve Map

     

    View Project Presentation to the Water Advisory Committee 8/3/15

    View the Press Release, 10/5/16