Town of Sunol Pipeline Replacement Project
Overview
Construction Look Ahead:
As of September 1, 2026 construction has been completed. There may still be activity on and around the site as our contractor demobilizes.
Phase 2: Work in the Arroyo de la Laguna Creek began in June 2026 and will be completed by September.
Phase 1 [complete]: In early August, 2025 we completed initial work, including the installation of a new pipeline through the Sunol Glen School athletic field.
School athletic field after completion of Phase 1
The Town of Sunol Pipeline Replacement project at Arroyo de la Laguna Creek is critical to continued operations and reliability of the water supply for the nearby town's residents. The current pipeline was laid in place nearly 100 years ago underneath the creek, but decades of scouring action by winter rains has lowered the creekbed and led the pipeline to be exposed above the surface. This places it at risk for damage. Replacing the aging pipeline and installing it deep under the creek bed is key to this project.
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Project Background
The current pipeline which provides water both for residents and businesses as well as for fire fighting, was installed in the early 1900s and originally was buried beneath the Arroyo de la Laguna creek. Due to the increase in runoff as a result of the construction of roads, buildings and other impermeable surfaces over the past century, the creek now receives more water during the winter rainy season than it did prior to the 20th century. This has caused it to scour a deeper channel, uncovering the pipeline and exposing it to potential impacts from debris.
The Town of Sunol Pipeline Replacement Project scope includes replacing approximately 550 feet of 12” diameter pipeline crossing Arroyo de Laguna Creek with 12” diameter Ductile Iron Pipe. To achieve this will require an open cut trench across the creek during construction, as well as new tie in points with gate valves. The project will include creek restoration after the pipe is installed and tree removal in the pipeline alignment as well as removal of existing pipeline within the creek from bank to bank.
The new pipeline segment will extend northwest deep underneath the creek and below the adjacent athletic field of the Sunol Glen School, a historic 100-year old building. After trenching and placement of the pipeline, scheduled to occur when school is not in session, the affected strip of the athletic field will be restored to its current condition.
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Approximate Work Area
- Project Materials