Visitors hoping for a midweek nature respite in Menlo Park will have to wait. Flood Park and all of its facilities — including the bike pump track, multi-use field, sports courts and walking paths — will be closed every Wednesday starting Sept. 9 through the end of October. The reason? Too many ground squirrels, county officials said.
The rapidly growing ground squirrel population has caused damage to walkways and trees, according to San Mateo County’s Parks and Recreation Department. The department, in partnership with the U.S. Department of Agriculture’s Wildlife Services Division, said in an Aug. 31 press release that it will be using a number of approaches to reduce the population of ground squirrels, including fumigation and setting live traps near burrows in Flood Park.
The department said that its techniques are safe for the public and will not harm wildlife other than the ground squirrels. No poison or bait boxes will be deployed, according to the press release. The fumigation, which will use sodium nitrate and charcoal, is considered to be the safest method and “doesn’t get out and hurt other animals,” said Jeneane Crawford, county parks’ communications manager.
Ground squirrels, unlike their tree-climbing counterparts, create burrows underground to rest, store food and raise their young. In addition to fleas, mites and diseases, the dirt-colored rodents can carry hantavirus and the bubonic plague, said Crawford.
Crawford said ground squirrels have previously undermined park equipment and this is not the first time Flood Park has been closed for this kind of pest control.
A fallen tree in Flood Park in Menlo Park on Sept. 1, 2026. Photo by Seeger Gray. 
A ground squirrel peeks out of a hole at the roots of a fallen tree at Flood Park in Menlo Park on Sept. 1, 2026. Photo by Seeger Gray. 
A tree in Flood Park in Menlo Park on Sept. 1, 2026. Photo by Seeger Gray. 
A hole at the base of a tree trunk at Flood Park in Menlo Park on Sept. 1, 2026. Photo by Seeger Gray.
Flood Park is located at 215 Bay Road in Menlo Park. For more details on the county’s pest control efforts, see the FAQ.
