Maple Creek to Willow Creek Transmission Reliability Project

Location: Maple Creek and Willow Creek, California
Client: Pacific Gas and Electric

The Maple Creek – Willow Creek 60 kV Reliability Project (project) was initiated to improve transmission system reliability between the PG&E Maple Creek and Willow Creek substations.  The project proposal includes a combination of maintenance activities to improve system reliability along approximately 20 miles of 60 kV power lines and maintenance work on over 400 structures. CH2M Hill and DZC successfully partnered to assist PG&E to analyze multiple permitting possibilities, provide a risk assessment for each, and submit several approaches to consider different levels of cost, timing, and minimizing environmental effects during construction. The 20-mile transmission line contained over 400 power poles and crossed multiple jurisdictional boundaries including BIA, USDA Forest Service, and numerous private land holders.

DZC initially provided a high level constraints analysis that presented the site types common to the area and an analysis of expected processes, issues, and procedural requirements (Section 106 or CEQA) based on site type or land ownership. As not all poles were to receive sub-surface disturbance, DZC created a probability model to select which non-ground disturbance segment retained a high potential for surficial cultural resources to support due diligence efforts on behalf of PG&E.

DZC survey crews surveyed over 13 miles of transmission line (250+ poles) within the utility Right of Way and documented fifteen archaeological sites. Terrain ranged from ridgetop prairies to river worn canyons. DZC The predictive model was acceptably successful in identify several large precontact complexes and information gathered from the sample in rougher terrain will assist in informing future models. DZC also coordinated with two federally recognized tribes to address site specific concerns and monitoring approaches that would incorporate tribal members. DZC and CH2M Hill also coordinated with Federal agencies to seek concurrence with proposed recommendations prior to final submittal to ensure a timely document review with few no comments to address.

Deliverables included an Initial Project Review, an EPlan, and a number of discipline specific reports in the appendices, including a Phase 1 Cultural Resource Inventory Report from DZC. Construction work is expected to take place in August 2018 and it is expected that DZC will receive a contract extension to complete the monitoring phase of this project.