The work is likely to be finished by April 10, 2009.
Power generation at the Nimbus power plant will be impacted as the power transmission line is linked to the Folsom Substation.
As water cannot be released through the power stations at the time of substation work, it will instead flow through the spillway gates on Nimbus and Folsom dams and will be easily visible.
The work will have no impact on water supplies and will not affect the amount of water released. Releases will remain in harmony with needs to meet downstream environmental and water supply requirement while preserving cold water in Folsom Reservoir.