SJC Conservation Land Bank and OPALCO collaborate on Power Line Improvements

bird survey 5.31.2020

In collaboration with the SJC Conservation Land Bank, OPALCO will soon begin replacing power poles on the south side of Turtleback Mountain Preserve. Broadly, this project will improve the safety and reliability of the power supply to the communities of Deer Harbor, Spring Point and Massacre Bay. Project details, including the timing of the actions and follow-up plans to sow native seed, were specifically designed to reduce negative ecological impacts within the power line corridor.

The lines on Turtleback Mountain were installed in the 1950’s and the poles were last replaced in early 1980’s. In addition to replacing these vulnerable, aging poles, OPALCO will remove trees growing within approximately 50 feet of the power lines. This protects the utility from wind damage and the potential to either cause or to be cut-off by wildfire.

Potential ignition sources from the replacement work, soil disturbance, tree removal and its impacts to nesting birds, and operational feasibility were all discussed, and the following considerations have been made in partnership:

Public Safety and Fire Risk – Informational signage will be placed at preserve entrances and at the access point. Fire prevention and management equipment will be staged on-site and, as necessary, tall grass will be mowed to reduce fuel. Ultimately, this project will reduce fire risk from power line damage, reduce the need for future line maintenance and tree trimming, and improve emergency access.

Tree Removal – Most of the trees identified for removal are small-diameter Douglas firs in an area that was historically Garry oak savanna. The removal of these conifers is compatible with the Land Bank’s ongoing efforts to enhance rare and valuable oak habitat. A few small madronas and firs will be removed for vehicle access but care was taken to preserve mature trees. Wood will be left for wildlife habitat, chipped, and potentially scattered or burned in a manner that minimizes carbon emissions.

Wildlife Impacts – A nesting bird survey will be performed prior to the start of work. Trees found to have active nests will be given special consideration and may be potentially buffered from the treatment in the short-term. Larger trees that lean away from the power lines will be converted into snags for cavity nesters. Other larger logs will be left on the ground as habitat for wildlife.

Soil Disturbance – Heavy equipment use makes surface ground disturbance unavoidable, but several strategies will be employed in order to minimize the impact. These include: initiating the work during the early summer months, flush-cutting trees rather than removing stumps, utilizing wood chips and operating within a defined access route. Temporary access points will be established near the Morning Ridge Trail, along an old logging road, and from an adjacent private property on Bobbyann Road. All disturbed areas will be restored with native seed.

Proposed Schedule
Tree removal will begin the week of June 8th and continue in phases throughout the month. Pole replacement is scheduled for early July with project completion by year end. There will be little disruption to trail users; access to the work area will be temporarily blocked, but once equipment is in place, trail users should find the project minimally disruptive.

A tailgate session is open to the public on Wednesday, June 10th from 11:30am-1pm at the South Turtleback Trailhead parking lot; staff will be available to answer questions. For additional information about this project, please contact Peter Guillozet (Orcas Preserve Steward), at peterg@sjclandbank.org or Terry Turner (OPALCO Line Clearance Manager) at TTurner@opalco.com.