Santa Rosa Aqueduct Seismic Hazard Mitigation Project
Summary
SCH Number
2009118214
Public Agency
Sonoma County Water Agency
Document Title
Santa Rosa Aqueduct Seismic Hazard Mitigation Project
Document Type
NOE - Notice of Exemption
Received
Posted
11/30/2009
Document Description
The 1959 Santa Rosa Aqueduct at the Rodger's Creek Fault Crossing is currently a 36" cement-mortar lined and coated steel pipe with bell-and spigot connections, serving the City of Santa Rosa, the City of Sonoma, Sonoma Valley, and the Valley of the Moon Water District, accounting for 221,760 people, businesses, hospitals, and schools. The Agency's Santa Rosa Aqueduct is connected to both the southern and eastern aqueduct transmission lines; therefore, if this aqueduct were to suffer a complete failure in an earthquake, it could potentially result in a loss of water to the entire population served by the Agency-over 600,000 people and businesses. It was estimated that 200 feet of roadway could be washed out as a result of water main rupture. There are 2,000 lineal feet of water main with the highest risk of failure in the zone of fault deformation. This parallel pipeline will be constucted of welded steel. Isolation valves and manifolds will be installed at each end of the fault deformation zone so that temporary flexible pipelines can be installed in the even repairs are needed to either pipeline. In order to install the secondary pipe, the project site (roadway) would be cut and a sufficient amount of material removed to accommodate the new 2,000 linear foot, 36" diameter pipe. An asphalt overlay would then be completed to restore the road surface.
Contact Information
Name
Rachel Vail
Agency Name
Sonoma County Water Agency
Contact Types
Lead/Public Agency
Phone
Location
Cities
Santa Rosa
Counties
Sonoma
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
15304
Reasons for Exemption
Routine seismic retrofit of facilities to meet current seismic standards and public health and safety standards without expansion of capacity or the removal of any mature scenic trees. The proposed activity includes excavating and making modifications to an underground water main located under a city street. All work will be completed within the public right-of-way and will not disturb any ground that has not already been disturbed as a result of previous public improvements.
Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at state.clearinghouse@opr.ca.gov or via phone at (916) 445-0613.