Route 101 Marin Sonoma Narrows A1

15 Documents in Project


SCH Number
Lead Agency
California Department of Transportation, District 4
Document Title
Route 101 Marin Sonoma Narrows A1
Document Type
NOD - Notice of Determination
Document Description
To accommodate the Marin Sonoma Narrows High Occupancy Vehicle Widening Project, the bridge at Novato Creek will be widened into its median by ~19 ft. The bridge extension will be a cast-in-place reinforced concrete T-beam superstructure, including new concrete bent caps and abutments. The substructure will consist of Class 140 driven pre-cast concrete piles at the abutments and driven cast-in-steel-shell (CISS) piles at the bents. It is anticipated that four 2 ft diameter CISS piles would be required per bent for a total of 16 piles for the 4 bents. The construction of the CISS piles will include pile driving down the steel pipe pile into the ground, removing the soil inside the steel pile, inserting rebar cages into the pipes and filling the pipes with concrete. To accommodate this work some existing piles will be removed by crane or through use of vibratory methods. To avoid impacts to salmonids, pile installation work will be limited to the June 15 through October 15 dry season. Temporary falsework bents will be placed in the creek with steel beams spanning across the falsework bents. Plywood decking will be placed between the steel beams to allow for the placement of bar reinforcing steel and construction of the superstructure. At the route 101/37 interchange there will be a culvert replaced and a headwall installed with rock slope protection (RSP). As a result ~240 sf of willow thicket and blackberry will be impacted. Approximately 26 cy of native material will be removed and replaced with concrete and RSP for the headwall installation.

Contact Information

Melissa Escaron
Agency Name
California Department of Fish and Game
Contact Types
Lead/Public Agency


Novato, Petaluma
Marin, Sonoma
Cross Streets
US 101 / Route 37, US 101 / Route 116
State Highways
37, 116
Gnoss Field
San Pablo Bay, Petaluma River, various creeks

Notice of Determination

Approving Agency
Approving Agency Role
Responsible Agency
Approved On


(1) The project will have a significant impact on the environment
(2a) An Environmental Impact Report was prepared for this project pursuant to the provisions of CEQA
(2b) A Mitigated or a Negative Declaration was prepared for this project pursuant to the provisions of CEQA
(2c) An other document type was prepared for this project pursuant to the provisions of CEQA
(3) Mitigated measures were made a condition of the approval of the project
(4) A mitigation reporting or monitoring plan was adopted for this project
(5) A Statement of Overriding Considerations was adopted for this project
(6) Findings were made pursuant to the provisions of CEQA

Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at or via phone at (916) 445-0613.

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