Springbrook Road near Sherwood Way in Walnut Creek will close to through traffic on weekdays for two months starting Thursday, Oct. 1 while crews replace a damaged culvert and repair a sinkhole.

The Contra Costa County Public Works Department announced the $527,675 project will run through Nov. 30, weather permitting. Work hours are 7 a.m. to 5 p.m. Monday through Friday, excluding holidays.

The road will shut down between east of Sherwood Way and south of the work zone during construction hours. Residents who live along the closure can expect delays of up to 15 minutes. Detour signs and message boards will direct drivers around the site.

What's being fixed

Workers will rip out a 36-inch corrugated metal pipe beneath the road and replace it with 62 linear feet of reinforced concrete pipe and 29 linear feet of cast-in-place box culvert. The project also includes new drainage structures, manholes, repaving and fresh lane striping.

The county awarded the contract to GradeTech, Inc. on Aug. 25 following an Aug. 18 bid opening. A pre-construction meeting was held Sept. 14.

Funding and contacts

Federal emergency relief funds and local road funds are covering the cost. The project has been in development since at least July 2024, when a preliminary environmental study was submitted. Federal environmental clearance came through in October 2025.

The county's public alert lists Nick Panayotou as the construction contact at 650-642-5299. Kelly Kalfsbeek handles media inquiries at 925-313-2115.