PROJECT LOCATION AND Description

Located in the San Francisco Bay, San Pablo Bay and Mare Island Strait are two federal channels that provide deep-water access to the Suisun Bay Channel and the Ports of Sacramento and Stockton, and to Napa River, respectively. This project provides for maintenance dredging of (1) a 600-foot wide channel to a depth of 35 feet Mean Lower Low Water (MLLW), which is approximately 11 miles long, in San Pablo Bay across Pinole Shoal with a maneuvering area adjacent to Oleum Pier at the mouth of Carquinez Strait; (2) a 600-foot wide channel to 30 feet MLLW through Mare Island Strait, flaring to a turning basin generally 1,000 feet wide, from former dike number 6 to within 75 feet south of the causeway between Mare Island and Vallejo; (3) a channel to 30 feet MLLW up the Napa River, except (4) at the northerly end, at the City of Vallejo Marina, where the project depth is 26 feet MLLW. Historically, San Pablo Bay has been dredged every other year, most recently in 2023 and 2025, based on restrictions on government hopper dredging in SF Bay.  Maintenance dredging of Mare Island Strait was last performed in mid-1990s. With the closure of the Mare Island Naval Shipyard, the Mare Island Strait is no longer maintained at authorized project depth for deep draft vessels. The channel is self-scouring and based on condition surveys is maintaining 28-foot depth.  

FY 26 ACCOMPLISHMENTS

• Updates are in progress. Check back soon for more information.

FY 25 ACCOMPLISHMENTS

• Dredging of San Pablo Bay completed.
• District conducted economic analysis of whether there is a federal interest in resuming dredging of Mare Island Strait to authorized depth of -30 ft MLLW.

FY 24 ACCOMPLISHMENTS

• Annual condition survey conducted on the channel.
• Planning and design level of effort performed in preparation for the FY25 dredging episode.

ISSUES AND OTHER INFORMATION

• The Corps conducts periodic surveys to monitor the rate of shoaling on Mare Island Strait.

CONGRESSIONAL INTEREST

• 8^th District, Rep. John Garamendi

POINT OF CONTACT

• Deputy for Project Management, Thomas R. Williams, 415-503-6560

Updated on 20 February 2026