The Ygnacio Valley Library will shut its doors Wednesday, Sept. 9, 2026, for roughly nine months of construction, sending patrons to the Walnut Creek Library on North Broadway for hold pickups and other services through spring 2027.

Crews will replace the branch's HVAC system and roof and overhaul its electrical and lighting systems. The building is more than 50 years old. The library expects to reopen around Monday, May 31, 2027.

The project is funded by Contra Costa County's Measure X sales tax, the half-cent levy approved by county voters in November 2020 that generates about $120 million a year, supplemented by county library reserves. No specific dollar amount for the Ygnacio Valley project has been released.

Tuesday, Sept. 8, is the last day patrons can pick up existing holds at the branch. Starting Sept. 9, uncollected holds will transfer to the Walnut Creek Library at 1390 N. Broadway. Parking is available at the Broadway Garage at the same address, with the first hour free.

During the closure, the Ygnacio Valley book drop and parking lot will also be closed. Patrons can borrow or return materials at any open Contra Costa County Library branch, including the Clayton, Concord, and Pleasant Hill locations.

The city of Walnut Creek has already moved to absorb some of the extra demand. Effective Wednesday, July 1, the city increased its supplemental funding of the Walnut Creek Library from 12 to 16 additional service hours per week, bringing total weekly hours from 52 to 56 through June 2027, according to the East Bay Times. The city cited the anticipated surge from displaced Ygnacio Valley patrons.

The Ygnacio Valley renovation is one of four major infrastructure projects the county library system is undertaking over roughly two years. The Pinole, Antioch, and Kensington branches are also slated for upgrades. County Librarian Alison McKee, in a February 2026 letter announcing the program, wrote that the projects address aging infrastructure in buildings more than five decades old and will keep the branches open and comfortable for years to come.

For account questions during the closure, patrons can call (800) 984-4636. The next milestone is the targeted reopening around May 31, 2027.