SR-84 Sinkhole and Culvert Repair DO (EA 4X430)
Summary
SCH Number
2025101535
Public Agency
California Department of Transportation, District 4
(DOT)
Document Title
SR-84 Sinkhole and Culvert Repair DO (EA 4X430)
Document Type
NOE - Notice of Exemption
Received
Posted
10/31/2025
Document Description
Caltrans proposes repairing a sinkhole and failed culvert on SR-84 in San Mateo County at post mile 16.07. Maintenance Services discovered the sinkhole on August 4 and Field Maintenance installed a steel plate over the sinkhole temporarily so the lane could be reopened to traffic. The sinkhole extends approximately 4 feet toward the median, 15 feet back toward a cross culvert, and daylighted 20 feet down the slope along the roadway. It was determined that an 18-inch corrugated metal pipe (CMP) cross culvert had failed, causing water to intrude into the roadway subbase. The water seepage resulted in loss of subbase material and eventually crated the sinkhole. The project proposes to first remove the undermined roadway section and loose material from the sinkhole. The sinkhole will be repaired by reconstructing the subbase. The existing damaged section of the 18-inch CMP cross culvert will be removed and replaced with a new culvert section of the same size. The roadway will then be repaved using hot mix asphalt. Traffic control, temporary railing (type K), and a temporary signal will be required during construction.
Contact Information
Name
Juliane Smith
Agency Name
Caltrans
Job Title
Senior Environmental Scientist (NEPA/CEQA Specialist)
Contact Types
Lead/Public Agency / Project Applicant / Parties Undertaking Project
Address
Phone
Email
Location
Cities
Woodside
Counties
San Mateo
Regions
Northern California, San Francisco Bay Area
State Highways
SR-84
Other Location Info
The project is located on SR-84 in the City of Woodside, San Mateo County, at post mile 16.07.
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
PRC 21084; 14 CCR 15301 Class 1(c)
Reasons for Exemption
Class 1(c) Existing Facilities. The project is not anticipated to result in any environmental impacts. The project contains a number of standardized project measures which are employed on most, if not all, Caltrans projects and were not developed in response to any specific environmental impacts resulting from the project.
County Clerk
San Mateo
Attachments
Notice of Exemption
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