CSW|ST2 provided engineering design and construction support services for the aqueduct relocation necessitated by the improvement of US 101 between Novato and Petaluma. The Caltrans Marin-Sonoma Narrows (MSN) Project is proposed to upgrade the existing Route 101 between Novato and Petaluma from an expressway, with at-grade intersections and driveway access, to a freeway, with interchanges and frontage roads to provide access to intersecting roadways and adjacent parcels.

The proposed roadway improvements and Right-of-Way expansion within are in conflict with the existing 30-inch aqueduct which is owned and operated by the North Marin Water District (NWMD). The highway project has been divided into three segments, each approximately 2 miles long. CSW|ST2 is working as a subconsultant to two of the highway design firms to design approximately five miles of replacement aqueduct.

US 101 Widening at Marin Sonoma Narrow

US 101 Widening at Marin Sonoma Narrow