SON SR-1 Culvert Rehabilitation
Project
Project Description
Caltrans proposes to replace three culverts at different locations (Location 1 at PM 19.25 and Locations 2 and 3 at PM 21.84) (Figure 1-3, Map 1 and 2). The Project would also include removing one tree at Location 1 and removing and replacing a drainage inlet, flared-end section, concrete spillway, concrete apron, and rock slope protection (RSP) at Locations 2 and 3. The Project footprint totaling 0.29 acre, encompasses the maximum extent of construction-related activities for the locations, including staging, as well as disturbed areas outside the Caltrans right of way (ROW).
Click on the two maps below to see a larger version.
Figure 1-3 Location 1 Project Components
Figure 1-3 Locations 2 and 3 Project Components
Project Components
Culvert Work
The existing 90-inch corrugated steel pipe (CSP) at Location 1 would be replaced in kind with a new 90-inch CSP culvert. Although the drainage system does not convey runoff volumes that would warrant a 90-inch-diameter culvert, Caltrans has chosen to replace the existing culvert at Location 1 in kind to maintain its potential use as a wildlife crossing.
The existing 18-inch-diameter, 66-foot-long CSP culvert at Location 2 would be replaced with a 24-inch-diameter, 66-foot-long CSP culvert.
The existing culvert at Location 3 would be replaced with a CSP of the same size. The pipe would also feature a polymeric sheet coating (i.e., a thick pipe wall with a protective coating) or a structural plate pipe with thicker steel along the invert (bottom of the pipe).
Rock Slope Protection
Rock slope protection (RSP) has not been installed on either end of the existing culvert at Location 1. The Project does not propose to install RSP at Location 1.
The Project would remove the concrete spillway located downstream of both culverts at Locations 1 and 2 and replace it in kind with a new concrete spillway (Figure 1-3). Additionally, approximately 0.003 acre (130 square feet) of the RSP located downstream of the culverts at Locations 2 and 3 would be removed and replaced.
The concrete apron located upstream of the culvert at Location 3 would be removed and replaced with RSP.
Flared-End Section
Flared-end sections (FESs) have not been installed on either end of the existing culvert at Location 1. The Project does not propose to install an FES at Location 1.
FESs have not been installed on either end of the existing culvert at Location 2. The Project does not propose to install an FES at Location 2.
An existing FES is located east of the northbound lane of SR 1, on the Location 3 culvert. The Project would remove the existing FES and replace in kind with a new FES.
Drainage Inlet
Drainage inlets (DIs) have not been installed within the northbound or southbound lanes of SR 1 at Location 1. The Project does not propose to install DIs at Location 1.
The Project would remove the existing DI west of the southbound lane of SR 1 at Location 2 and replace it in kind with a new DI in the same location within the southbound shoulder.
Existing DIs have not been installed in association with the culvert at Location 3 and the Project does not propose to install DIs at this location.
Temporary Creek Diversion System
Replacement of the culvert at Location 1 would require a temporary creek diversion system (TCDS) to provide a dry working environment and control sediment within the creek during construction. The final design would be determined during construction but could consist of temporary installation of a gravel-filled-bag cofferdam or sheet pile dam.
It is not anticipated that a TCDS would be required for the culvert at Location 2.
Replacement of the culvert at Location 3 would require a TCDS to convey water through work areas during the construction period. The final design would be determined during construction but be constructed similarly to the TCDS for Location 1.
Access and Staging
Staging areas for the overnight storage of equipment and materials would be limited to areas within the Caltrans ROW, such as the closed lane adjacent to the culverts that are being removed and replaced. Staging areas are anticipated to be determined prior to the PA&ED phase. Access to driveways and roadways adjacent to the construction area would be maintained by implementing the measures described in the Traffic Management Plan (TMP).
Right of Way Requirements
Construction-related activities, including staging areas, would primarily occur within Caltrans ROW. Location 1 would require two permanent drainage easements to conduct construction-related activities and maintain Project components outside the Caltrans ROW. Locations 2 and 3 would require one permanent drainage easement, one temporary construction easement, and one permanent highway easement to conduct construction-related activities and maintain Project components.
Construction Methods
Schedule:
Begin construction August 2024 and conclude February 2025.
Construction is anticipated to take approximately 6 months or 120 working days to complete.
Construction activities would be limited to daytime hours only.
Stage 0:
-Install construction area signs, environmentally sensitive area (ESA) fencing, construction best management practices (BMPs), and temporary creek diversion system (TCDS) prior to construction.
Stage 1:
-Closing the lane adjacent to the culverts being upgraded.
-Restriping for temporary one-way alternating traffic control.
-Installing temporary barrier systems and temporary crash cushions along the centerline of SR 1.
-Installing temporary traffic signals along the approach sections.
-Staging areas would be established within the lane closed to traffic (i.e., within Caltrans ROW) for the overnight storage of equipment and materials.
-Installing portion of the culvert within the closed lane.
Stage 2:
-Clearing and grubbing vegetation prior to removing and replacing portions of the existing culverts adjacent to the lane closed to traffic in both directions.
-The culverts would be removed; new culverts, flared end sections, drainage inlets, spillways, aprons, and RSP would be constructed; the area would be backfilled and the highway repaved; and vegetation control would be installed.
-This construction methodology would then be repeated on the other side of SR 1, with the previously closed lane reopened.
Stage 3:
-Removing temporary TCDS, temporary BMPs, ESA fencing, temporary barrier systems along the centerline of SR 1, temporary crash cushions, temporary traffic signals along the lane-closure areas, and construction area signs.
-Restriping of the highway.
-Reopening the closed lane to the traveling public.
Equipment Would Include:
-Utility truck, Air compressor, Augers Back hoes, Excavators, Cranes, Dump trucks, Jack hammer, Hydraulic pumps, Pavement cutter, Concrete truck, Generator, Vacuum, Water truck, and Street sweeper
Project Location Photos
Photo 1: Downstream View of Culvert Location 1 – PM 19.25, Looking South
Photo 2: Upstream View of Culvert Location 1 – PM 19.25, Looking North
Photo 3: Downstream View of Culvert Locations 2 and 3 – PM 21.84, Looking East
Photo 4: Upstream View of Culvert Locations 2 and 3 – PM 21.84, Looking Northeast
Photo 5: Downstream View of Culvert Locations 2 and 3 – PM 21.84, Looking West