Canadian electric utility BC Hydro is moving the completion of the last phase of the ongoing dam safety upgrades to Elsie dam into 2004. The remaining upgrades are scheduled to begin in late 2003 or early 2004 and continue throughout the remainder of 2004.
Major dam safety upgrades have been completed over the past two years to improve the safety of the dam against earthquakes. The reservoir has been operating at normal levels since November 2001.
‘Work completed to date has resolved the primary seismic deficiencies,’ said BC Hydro project manager Alex Selnes. In 2001 this included the removal of potentially liquefiable layers in the Main dam and Saddle dam 1 as well as the addition of a gated concrete spillway dam within the overflow spillway. This work allowed the reservoir to be returned to normal operations and now provides additional spillway capacity, improved reservoir level control and an alternate means of providing fish flows to the Ash River.
In 2002 improvements were made to the low-level water release facilities in Saddle dam 1. This included the replacement of the bulkhead gate and trashrack at the intake of the water release outlet, as well as the removal of the intake tower.
Work planned on the downstream end of the low-level water release, including extension of the outlet, rehabilitation of the water control valve, replacement of the conduit liner, final instrumentation, and the addition of a rock berm to Saddle dam 1 will be completed during 2004. This work was originally planned to be complete by the end of this year.
The schedule change is to allow BC Hydro more time to better examine the components and cost of the low-level water release improvements. ‘The alternatives have not been fully reviewed, so further analysis of all of the alternatives is being undertaken by the project team,’ said Selnes. ‘The selection of the preferred alternative will be made over the next few months.’
The Ash River Water Use Plan Consultative Committee, which completed its work in 2002, made recommendations for future flows to be released down the Ash river as well as other operational changes for the benefit of power and non-power interests. The recommendations of the water use plan will become part of BC Hydro’s operations once the Comptroller of Water Rights reviews and approves the plan.
The Ash river hydroelectric facility has a generating capacity of 27MW, or enough power to supply the energy needs for approximately 19,000 homes.