High Resolution Measurement of Levee Subsidence Related to Natural Gas Infrastructure in the Sacramento-San Joaquin Delta
Improving our understanding of subsidence in the Delta to manage risks to the energy system
U.S. Geological Survey
Recipient
Henderson, NV
Recipient Location
13th
Senate District
24th
Assembly District
$282,868
Amount Spent
Completed
Project Status
Project Result
This research team met with UC Berkeley contract 500-11-016 team, to identify and confirm areas of interest for subsidence monitoring; namely, areas with natural gas infrastructure expected to experience levee overtopping due to extreme storms and sea level rise within a century. The team performed field monitoring and sought feedback from the Technical Advisory Committee, including utility representatives, Department of Water Resources (DWR), and Delta Stewardship Council (DSC). The team concluded in its final report, that subsidence and sea level rise would result in some levees being outside engineering specifications by the middle of this century.( http://climateassessment.ca.gov/techreports/energy.html)
The Issue
Although State-sponsored research has made significant strides in investigating the impacts of climate change on the energy system, to date most of this research has focused on the electricity system. Prior research revealed significant subsidence in the Delta Island levee system but did not offer sufficient detail to assess and safeguard against risks to the natural gas system. This research responded to issues identified in a 2013 IEPR workshop, namely, the need to safeguard the natural gas system against the risks posed by a failing Delta Island levee infrastructure and aggravated by sea level rise.
Project Innovation
The researchers measured subsidence in the Delta Island levee system with unprecedented detail in space and time. Researchers studied the most critical areas of the Delta's energy infrastructure, which includes natural gas pipelines and storage as well as electricity transmission lines. Initial surveying occurred at the Rio Vista Gas Field, followed by Pacific Gas & Electric's (PG&E) McDonald Island gas storage, and then systematic scanning of levees associated with gas pipelines. A broader view of the levees in the Delta, including areas with important transmission lines, is needed to determine if levee subsidence is a local or a Delta-wide effect. This work improves on DWR's past monitoring of Delta subsidence, and may be incorporated into PG&E's risk management activities and the DSC's Delta Stewardship Investment Plan.
Project Benefits
The portable LIDAR measurement system developed as part of a prior Energy Commission project and further enhanced under this project allows for very low cost measurement of subsidence in the Delta and other regions. Traditionally this is done using airplanes, which increases costs considerably. This study contributes to California's Fourth Climate Change Assessment.

Reliability
California is at risk to major natural gas supply disruptions due to levee failures. This risk is compounded by sea level rise, which affects hydrodynamics in the Delta and can lead to inundation during extreme storm events. Research to identify the most vulnerable areas will inform efforts to boost resilience of California's natural gas system.
Key Project Members
