SMUD: 500-kV CoSu project canceled due to high cost

Sacramento Municipal Utility District (SMUD) on March 1 said that it is canceling the proposed 500-kV Colusa-Sutter Transmission Line Project (Co-Su), effective immediately, due to the project’s high cost.

SMUD said that during the project’s initial phase – which was to evaluate potentially significant environmental impacts, as well as conduct permitting and preliminary engineering to decide whether to proceed with final design and construction – it was determined that the project is too costly. The initial estimated $245m cost of the project has increased by more than $100m and could have ended up being significantly higher, SMUD said.

Additional cost increases were also expected to address flood risk at the O’Banion substation study area, SMUD said, noting that that issue was uncovered during the environmental review process. The decision to exit the project now comes early enough that SMUD will save about $4m in this planning phase, SMUD said.

SMUD noted that it and the Western Area Power Administration (WAPA) have been working on the project since the SMUD Board of Directors approved a project development agreement in December 2014. SMUD said that since its board made the initial approval, its staff and WAPA staff focused on developing a robust environmental review process, with numerous public meetings throughout four counties and studies to help ensure an appropriate mitigation strategy to minimize or avoid impacts on various resources.

The proposed line would have connected the California-Oregon Transmission Project to the transmission facilities of SMUD or WAPA on the west side of the Sacramento Valley, SMUD said.

SMUD noted that since it started planning the project, the development of SMUD’s long-term Integrated Resource Plan (IRP) has reduced the value and need of the proposed line. The IRP analysis indicates that SMUD would better focus its resources on the suite of local, regional, and in-state renewable and reliability projects, as well as incremental transmission infrastructure, SMUD said. Canceling the CoSu project also reduces pressure on SMUD rates during the early critical phase of IRP implementation, SMUD noted.

As TransmissionHub reported, according to a scoping report released by WAPA and SMUD, the project would involve construction, operation, and maintenance of a new single circuit, 1,190-MW transmission line that connects the California-Oregon Transmission Project (COTP) transmission lines to a substation in Sutter or Sacramento County. The project would also involve construction of substation facilities at the COTP interconnection point, including the installation of communication and protection equipment.

The scoping report added that the project is needed because it, among other things, addresses WAPA’s obligation to respond to a SMUD transmission service request under WAPA’s Open Access Transmission Tariff and provides new Central Valley Project (CVP) capacity for the benefit of all WAPA customers, and ensures a new transmission path to the COTP allowing SMUD and WAPA to schedule energy delivery.

About Corina Rivera-Linares 3286 Articles
Corina Rivera-Linares was TransmissionHub’s chief editor until August 2021, as well as part of the team that established TransmissionHub in 2011. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial from 2005 to 2011. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines.