SR-128 Calistoga Rock Slide and Washout Repair DO (EA 04-3X420)
Summary
SCH Number
2025070529
Public Agency
California Department of Transportation, District 4
(DOT)
Document Title
SR-128 Calistoga Rock Slide and Washout Repair DO (EA 04-3X420)
Document Type
NOE - Notice of Exemption
Received
Posted
7/14/2025
Document Description
Caltrans proposes to repair a rockslide and washout that was caused by the winter storms on westbound SR-128 from post mile 16.61 to 16.71. The storm events caused the westbound embankment slope to become saturated and unstable, therefore failing. At Location 1 (PM 16.61), a landslide approximately 190 feet wide, 40 feet long, and 3 feet deep occurred. At Location 2 (PM 16.65), the existing double-twisted wire mesh (DTWM) drapery system became loose and failed and the washout debris from the slope blocked the roadway and existing drainage inlet. At Location 3 (PM 16.71), a landslide approximately 165 feet wide, 45 feet long, and 3 feet deep occurred. At Locations 1 and 3, loose debris and materials will first be removed within the limits of the washout area and the slope will be graded. Rock slope protection (RSP) fabric, class 8, will be placed in conformance with Caltrans’ Standard Specifications Section 72-2.02C over the excavated areas. Then class 6, ¾ ton RSP (Type A Placement) will be placed overt the class 8 fabric. Three-point bearing for rocks must be achieved. At Location 2, the loose material on the slope will first be removed and the brow of the slope will be graded to match the adjacent slopes. Then the existing DTWM drapery system will be repaired by adding extra anchors. Sections of the drapery system that have totally failed will be replaced. The drainage system will also be repaired. Project construction will require one-way traffic control with temporary portable traffic lights. Temporary k-rail will also be installed 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
Unincorporated Sonoma County
Counties
Sonoma
Regions
Northern California, San Francisco Bay Area
State Highways
SR-128
Other Location Info
The project is located in Sonoma County on westbound SR-128 from post mile 16.61 to 16.71 by Maacama Creek, near Calistoga.
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
PRC 21084; 14 CCR 15301 Class 1(d)
Reasons for Exemption
Class 1(d) 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
Sonoma
Attachments
Notice of Exemption
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