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Underground Flow Equalization System

UFES Project Update – August 1, 2023

UFES Project Reaches Another Important Milestone

The UFES project has made great progress this season. As of July 24, 2023, the concrete work for the main UFES structure at the San Mateo County Event Center site is complete. Mechanical, electrical, and backfill work is still in progress. Construction continues on the diversion structure on South Delaware Street near the intersection with Saratoga Drive.

The ongoing pipeline work along South Delaware Street and Saratoga Drive continues to ramp down; with minor traffic pattern changes continuing through the summer in the vicinity of the Event Center and nearby side-streets while crews complete the work. Please watch for traffic signs, which are placed in specific areas to provide direction and ensure the safety of drivers.

The City anticipates that the UFES project in its entirety, including work at the Event Center, will conclude by the end of 2023. Once the project is complete, it will be able to reduce the sanitary sewer overflows that result from excessive rainfall, which the community may have witnessed during the recent storms.

Approved work hours are as follows:
San Mateo County Event Center Site: 7 a.m. – 7 p.m.
Saratoga Drive: 7 a.m. – 5 p.m.
South Delaware Street: 7 a.m. – 5 p.m.

*Construction schedules and traffic patterns are subject to change.

Inside new UFES structure
A peek inside the UFES structure at the San Mateo County Event Center as it nears completion (June 7, 2023). Person in lower right corner for scale. Please click to enlarge image. (Photo courtesy of T. Williams/City of San Mateo)

Construction team inside new UFES structure
Clean Water Program staff inside the completed UFES Structure, July 11, 2023. Left to right: Mike Sutter, Eric Morkve, Max Karish, Tom Williams, Andy Sullivan, Deryk Daquigan, Azalea Mitch, Matt Fabry, Tom Ruark, Laura Webb, Dan DeSemple, Jenn Clarke, Leswin Dcunha, Mike Duvendack. Please click to enlarge image.

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.