Turning Basin and Marina Dock Improvements and Dredging

Background

The City of Petaluma aimed to enhance access to the Petaluma River for the community, upgrade docking amenities, and improve safety for public use of the turning basin and marina dock. Located in the heart of downtown Petaluma, the turning basin is conveniently close to many popular destinations, including dining spots, wineries, and artisan shops. The riverfront is a vital part of Petaluma’s charm and economy, with the historic downtown area, defined by the river, attracting recreational boaters, kayakers, bird watchers, and tourists. The turning basin, a central feature of the waterfront, serves as a hub for these activities

Petaluma’s waterfront is not only a recreational asset but also a testament to the city’s rich history and its evolution from a bustling port to a vibrant community hub. Ongoing projects, such as the turning basin dock replacement, highlight the city’s commitment to preserving and enhancing this vital area for future generations. The 500-foot transient dock, equipped with 30A power outlets and potable water, is available for day use or overnight berthing on a first-come, first-served basis.

Approach

In 2020, the City of Petaluma engaged Foth to provide comprehensive dredging support for the Petaluma River turning basin and the city marina. This initiative was part of the city’s broader effort to improve river access, waterfront amenities and safety. We began by conducting an analysis of sediment data from 2018. Additionally, Foth performed an analysis of the previously approved upland dredge material placement area. This survey revealed that the area lacked sufficient capacity to accommodate the proposed dredged materials. With these findings, Foth secured the necessary permits from state and federal agencies to proceed with the dredging, which was essential for securing approval for in-bay placement of the dredged material in San Francisco Bay. We worked closely with the city to prepare and solicit bids for the turning basin dredging project, guiding the city through the contract award process. The project was successfully completed in the fall of 2022.

Our role extended beyond dredging to include services related to the design, permitting, bidding, and construction management of the Petaluma River turning basin. Our team provided analysis of historical shoaling patterns, past dredging activities, and high-water stages of the basin. Based on these comprehensive evaluations, we offered recommendations for the pile configuration to support the anticipated loads of the new concrete floats. This included the removal of existing piles and timber floating docks, the fabrication and procurement of replacement concrete docks and steel gangways, and the re-installation of the docks, gangways, and steel piles. Float fabrication was completed in December 2023 and installation occurred during the environmental window of 2024. The new docks are now complete, providing access for the public to enjoy.

Results

This project underscores our expertise in managing complex marine infrastructure projects. By coordinating the combined projects, the city was able to save on overall budget. The use of a comprehensive approach, from initial assessment to final installation, allowed the city to achieve its goals of enhancing the Petaluma River turning basin and marina, improve functionality and safety of the waterfront, and contribute to the community’s long-term enjoyment and sustainability of this vital area.