Water Transmission Pipeline Seismic Hazard Mitigation at the Santa Rosa Creek Crossing
Summary
SCH Number
2021020029
Public Agency
Sonoma County Water Agency
Document Title
Water Transmission Pipeline Seismic Hazard Mitigation at the Santa Rosa Creek Crossing
Document Type
NOE - Notice of Exemption
Received
Posted
2/2/2021
Present Land Use
Public Right of Way
Document Description
An existing section of the Santa Rosa Creek Aqueduct crosses under Santa Rosa Creek and is at risk of failure during an earthquake due to liquefaction and lateral spread. The proposed project would help to reduce failure of this section of the Santa Rosa Aqueduct due to earthquake-induced liquefaction and lateral spread by relocating a section of pipeline (approx. 730 ft.) from the existing stream crossing to a location downstream under E Street and Sonoma Avenue. The relocated pipeline would use a trench-less technology to tunnel under the existing E Street Bridge and concrete box culvert into which the creek currently flows. The expected result is that the project would eliminate the Santa Rosa Aqueduct’s exposure to the free face of the creek and would help to reduce the risk of failure due to earthquake-induced liquefaction and lateral spread hazard at the existing pipeline stream crossing.
Contact Information
Name
Connie Barton
Agency Name
Sonoma County Water Agency
Contact Types
Lead/Public Agency
Phone
Name
Agency Name
Sonoma County Water Agency
Contact Types
Project Applicant
Location
Cities
Santa Rosa
Counties
Sonoma
Regions
Citywide
Cross Streets
Sonoma Avenue and E Street
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
15302(c) Replacement or Reconstruction and 15304(f) Minor Alterations to Land
Reasons for Exemption
The project would replace an existing utility system involving negligible or no expansion of use to reduce seismic vulnerability and meet public health and safety standards in a location near the same site as the existing pipeline and will have substantially the same purpose and capacity as the pipeline replaced. The project does not involve removal of healthy, mature, scenic trees. The project includes minor trenching and backfilling where surfaces are to be restored.