Humboldt 101 Drainage South

This project would rehabilitate 37 drainage systems along U.S. 101 in Humboldt County approximately from the Mendocino County line to Rio Dell. It is necessary to preserve the roadway and prevent potential damage from storm events by repairing failing and deteriorated drainage systems that have exceeded their design life.

Project Description

The project would replace culverts, downdrains, drainage inlets, headwalls, endwall, and retaining walls, as well as install rock slope protection and rock-lined ditches.


The environmental phase of this project is currently underway with construction anticipated from fall 2024 to the end of 2026.

Traffic Impacts


For more information, contact:

Julie Price, Environmental Coordinator

(707) 362-5431

Myles Cochrane, Public Information (Media inquiries)

(707) 498-4272

A well worn drainpipe emerges from a hillside and winds through narrow trees before ending at a waterway. Rust covers half of the pipe. A Caltrans worker in an orange reflective vest and a white hardhat looks on.

A metal downdrain lays across a hill adjacent to U.S. 101 in Humboldt County.