Tumbler Ridge Transmission Structure Update July 18
BC Hydro advises that its crews have made progress over the weekend in constructing new transmission structures on both sides of High Hat Creek that will bypass the threatened structures. Despite challenging field conditions, access to the new sites has been established and crews are now preparing for the placement of twelve wooden poles – 85 to 95 feet in length -- that will eventually hold the 230 kV transmission line.
Backup power and ongoing work:
In addition, as part of a contingency plan, today the first back-up generation unit arrived in Tumbler Ridge. This would serve as standby supplemental power to Tumbler Ridge’s existing back-up units for their critical infrastructure and emergency requirements if the threatened transmission structures fall. A second BC Hydro back-up generator is expected to arrive on Monday.
As many as 35 – 40 BC Hydro crews and contractors will be involved in building the new structures and facilitating the hook-up of the back-up generators. Crews and equipment have come from Vancouver, Prince George, Terrace, Vernon, Chetwynd, Ft. St. John, and Dawson Creek.
Potential Time lines:
If weather conditions remain stable and there are no unexpected delays, construction of the new structures could be completed by Friday. A planned outage will then be required to transfer the transmission line to the new poles. The exact timing of the planned outage will be confirmed in the next few days.
While power to Tumbler Ridge remains uninterrupted, the transmission structure continues to be threatened by unstable soils and excessive water. BC Hydro’s primary concern is for the safety of our crews and customers as we implement a plan that ensures power reliability.
We will continue to provide information and as much advance notice as possible of potential power interruptions. Information will also be posted through the offices and website of the District of Tumbler Ridge.
If the transmission structure should fall:
Should the transmission structure fall, a power outage will occur in Tumbler Ridge. In that event, the back-up generation units on site would serve all emergency and critical infrastructure needs in Tumbler Ridge. For other customers, the length of a potential outage would depend on progress on the long-term solution and whether other temporary solutions are feasible given the challenging ground conditions.
Additional Information:
BC Hydro field operations observed deteriorating conditions on Monday, July 11 around a wood pole structure that is part of the 230-kilovolt transmission
line to Tumbler Ridge. Monitoring of the site has been ongoing. This area has been subject to significant rainfall and high water levels at High Hat Creek,
leading to soil saturation on a hillside where the transmission structure is located. Last week, BC Hydro completed a geotechnical assessment and plans
were made to begin construction of new wood pole structures on both sides of High Hat Creek on higher, more solid ground.