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Underground Flow Equalization System

UFES Project Update – September 16, 2021

UFES Project Progresses to Next Phase at Event Center Site

The Clean Water Program’s Underground Flow Equalization System construction near the San Mateo County Event Center is making great progress. The City’s contractor has completed excavation at the Event Center site and is progressing to Phase Four of construction. Phase Four includes installation of foundation micro-piles. During this phase, a network of foundation piles will be drilled to support the underground structure, ensure it stays in place during seismic events, and prevent uplift (floating) from the naturally high groundwater levels in the area. Most of this work will occur in the excavated area below the ground surface, so noise levels at the street are anticipated to be below the City’s noise ordinance level (90 decibels at the property line).

Approved work hours at the Event Center site are between 7 a.m. and 7 p.m. Monday through Friday. The City will continue to monitor noise, dust, vibration, and groundwater levels throughout the construction process and keep you informed of any exceedances and corrective actions taken.

*Construction schedules and traffic patterns are subject to change.

Visualization of UFES Phase 4Visualization of Phase Four of UFES construction at the San Mateo County Event Center Site

UFES Traffic and Noise Update – UFES Pipeline Work

In early Fall 2021, the City’s contractor will backfill and pave the microtunneling pit near the main entrance to the Event Center. Once work at that location is complete, both eastbound lanes on Saratoga Drive from the Event Center entrance to 28th Avenue will reopen. The eastbound lanes on Saratoga Drive from South Delaware Street to the Event Center entrance will remain closed during the ongoing pipeline installation.

Starting the week of September 20, 2021, new traffic control devices will be placed at the intersection of Saratoga Drive and South Delaware Street as pipeline work continues onto South Delaware Street. Work at this location is expected to last through mid-2022.

The City’s contractor will be removing equipment such as sheet piles from some of the work areas. Please be aware that this activity will generate noise for approximately one to two days at each work area, and is expected to occur throughout mid-Fall 2021. We will continue to keep the community updated ahead of this work via newsletters and text message. Please sign up for text message alerts by texting the word “UFES” to 1-833-321-0231, or sign up for our newsletter.

Approved work hours for work along Saratoga Drive are between 8 a.m. and 4 p.m. Monday through Friday. Approved work hours along South Delaware Street are between 8 a.m. and 5 p.m. Monday through Friday. Traffic control measures remain in place and will be updated as work progresses. Signs are placed in specific areas to provide direction and ensure the safety of drivers.

*Construction schedules and traffic patterns are subject to change.

Traffic pattern map for UFES pipe workNew traffic patterns expected at the main entrance to the San Mateo County Event Center

Stay Connected with the UFES Project

The Clean Water Program’s UFES construction is well underway and we want to keep you informed. The team established multiple information channels for residents and business owners to stay connected.

  • Sign up for construction alerts (text the word UFES to 1-833-321-0231), email us at or call our hotline at 1-650-522-7250.
  • You can also visit our UFES project page to see project details and sign up for our e-newsletter. If you don’t want to opt in, but still want information, bookmark the link where we post our updates to the project website.