The park, located at 215 Bay Road in Menlo Park, closed while the San Francisco Public Utilities Commission installed a water pipeline, but for several months this summer, it looked like it might never reopen.
Faced with a demand to cut 10 percent from the county's operating budget, the San Mateo County Board of Supervisors at first recommended permanently shutting down the 21-acre park, which costs a minimum $205,000 annually.
The board later reversed course in June and approved enough funding to keep the park open for another six months after asking Menlo Park to take over its operation. That option remains on the table.
A new nonprofit, the Friends of Flood Park, is also working to save the park. According to the county, the nonprofit has already sent hundreds of volunteers to spruce up the park with paint and pruning.
The party starts at noon with a ribbon-cutting led by Supervisor Rose Jacobs Gibson and Assemblyman Rich Gordon, D-Menlo Park. No entrance fee will be charged.