The Ignacio-Mare Phase 2 project involved driven, 48” CISS piles on a fast-paced project in a sensitive ecological area.

The Project:

Phase 2 of the Ignacio Mare Island Tower Replacement Project represents a critical initiative aimed at the reconstruction of two essential electrical transmission towers situated in the ecologically sensitive areas of Marin and Sonoma counties. Located within tidal marsh complexes just north of the San Pablo Bay, these towers play a pivotal role in the regional power infrastructure, spanning across landscapes adjacent to Novato Creek and Petaluma River. Situated south of State Route 37, the project holds significance not only for its technical complexity but also for its strategic positioning within environmentally intricate terrains. The project is poised to address both infrastructural needs and environmental considerations, reflecting a balance between technological advancement and ecological stewardship.


Challenges:

Completion of this time sensitive and high priority infrastructure project while minimizing environmental impact in a highly sensitive, ecological area.

  • Access is the largest challenge for this project.
  • Tower to Foundation connection. Top of Pile is 22’ above existing grade.
  • Large Pile Diameter – Driven 48” CISS Piles

The Solution:

Utilizing our decades of experience, advanced civil engineering expertise and a magnificent team effort between Foundation Constructors, PGE, and various regulatory bodies, we implement an innovative solution that met all project objectives successfully.

  • Access (Tower 28)
    • FPWI fortified and widened a 1 mile section of levee road for 9-axle access to bring the crane to the tower location.
    • FPWI laid 300’ of mats over marsh land, from the end of the levee to reach the tower location.
  • Access (Tower 29)
    • FCI came off a barge to install a 200’ trestle to reach solid ground.
    • FPWI laid 200’ of mats over marsh land, from the end of the trestle to the tower location.
  • Tower to Foundation connection
    • FCI erected scaffolding to reach the Top of Piles that are 22’ above existing grade.
    • FCI utilized man-lifts to aid in this process.
  • Large Pile Diameter
    • Specialized equipment (Foundation Owned) utilized to install large diameter piles.

Related Links:

California Environmental Quality Act: https://ceqanet.opr.ca.gov/2023040735

US Army Corp of Engineers: https://www.spn.usace.army.mil/Missions/Regulatory/Public-Notices/Article/2410327/spn-2020-00347-pge-ignacio-mare-island-emergency-tower-replacement/Project scope: Matting Access, Barge work, Trestle, 48” CISS Pile