The electricity infrastructure in the ART Subregional Project area includes two power plants, an oil-powered peaking plant in Oakland and a natural gas and diesel-powered peaking and reserve plant in Alameda. High voltage transmission lines run underground and overhead and carry electricity from where it is generated to substations. Substations transform the power to a lower voltage to be carried by overhead and underground distribution lines to residences and businesses. These substations are clustered in Oakland and Alameda, although there is one in San Leandro and two in Hayward.
Natural gas, liquid petroleum, jet fuel, gasoline, and diesel fuels are transported by pipeline across the project area. Pipelines are generally high-carbon steel buried at a depth of three to four feet along railroad and state road right-of-ways, although some pipelines cross natural areas (e.g. marshes) and flood control and stream channels. For example, a major natural gas pipeline parallels Interstate 880 in the project area while another runs parallel to the shoreline from Emeryville to the Oakland International Airport.
Telecommunication infrastructure in the project area typically includes underground cables (e.g. fiber optic lines), overhead lines, or cellular (wireless) facilities. Underground cables are usually buried two to five feet deep with access points that allow for periodic maintenance and replacement. Many underground and overhead lines in the ART project area are located, similar to gas pipelines, in railroad and state road right-of-ways. Cellular telecommunication facilities, which are located throughout the project area, are necessary for wireless communications that support day-to-day and emergency response communications.
Geo-referenced data were only available for power plants and substations, and these were the only assets for which an analysis of exposure was conducted. The other types of infrastructure and facilities were assessed to determine vulnerability and consequence if exposed, without determining how many and which of these facilities will be exposed to sea level rise and storm events.
Power plants and substations have electronic and mechanical equipment that are highly sensitive to water, and these facilities may be forced to shut down in advance of potential flooding, or could be significantly damaged if exposed to flooding. Substation disruption can result in a loss of power to the areas served, while damage to peaking and reserve power plants is less likely to disrupt neighborhoods since they generally are not the principal source of power. Some service areas may be connected to more than one substation and in such cases the power may be transferred from one station to the other, minimizing disruptions to service.
Underground transmission and distribution lines are unlikely to be affected by sea level rise unless flooding results in erosion and scour where they are buried. However, while overhead lines may not be directly affected by flooding, high winds and strong currents during storm events could down power lines, causing service disruptions and in some cases structure fires, which would be particularly threatening if floodwaters block emergency responder access.
Buried pipelines are vulnerable to flooding, salinity intrusion, and rising groundwater levels. Pipelines that are not properly protected can corrode if exposed to salt water, and those that are not weighted or anchored could float, particularly during prolonged flooding in marshy or sandy soils. Rising groundwater can increase the susceptibility of soils around the pipeline to liquefaction, potentially leading to significant damage as long pipelines are at risk of deformation and breaking during an earthquake when soils liquefy. Damage to pipelines will not only cause service disruptions but could have significant consequences to public health, safety and the environment if there are breakages or failures that result in explosions, fire or a release of hazardous contents.
Damage of telecommunications infrastructure due to flooding, high winds that cause toppling, or loss of power to these systems will disrupt communication, hindering emergency response activities and affecting the everyday lives of residents and businesses. Redundancy of telecommunication options (e.g., internet, landline, and mobile phone) reduces the overall system vulnerability and the consequence for those that rely on them. However, people who rely on a single type of communication system will be less resilient.
For all three of these systems, there was a lack of readily available public information, which made it challenging to understand the vulnerability of specific facilities within the project area to sea level rise and storm events. For example, information on the location and depth of pipelines or the location and type of telecommunications infrastructure was not publicly available, nor was information about the status of power plant and substation shut down procedures, or information about electricity substations service areas or redundancy.
For more information:
- Lindy Lowe