Ground squirrels are eroding the bluffs in Pismo Beach. What should the city do?
Worsening erosion of the Shell Beach bluffs has pushed the city of Pismo Beach to look at plenty of options to keep the coastal community stable — and now ground squirrels are in the city’s crosshairs as a result.
At its April 15 meeting, the Pismo Beach City Council heard a report from the city’s Public Works Department about the risk the typically harmless rodents pose to the blufftop community.
According to the staff report, around two years ago the City Council instructed the city’s staff to stop using bait to control the ground squirrel population to keep pets and non-target animals from eating it.
Since then, the ground squirrel population has “exploded” despite the Public Works Department’s efforts to curb the rodents by injecting carbon monoxide into their holes, Public Works director Rosemarie Gaglione said during the meeting.
As a result, with more ground squirrels than ever tunneling into the rocky soil of the bluffs, the threat to the fragile shoreline has increased.
Controlling a ground squirrel population isn’t as easy as it may sound — but the city does have several options it could pursue.
City to evaluate ground squirrel control options
Assistant city manager Mike James said the number of ground squirrels responsible for the bluff damage is not known at this time.
Though the city staff considered reintroducing bait in the past two years, the state banned most rodent poisons in that time, leaving the city with only one poison option to consider.
Several methods, such as Rozal poison, are less effective than others, according to the staff report.
Rozal is highly toxic to people and animals — particularly dogs — and isn’t ideal for a park setting such as Eldwayen Park, which is frequented by walkers and pet owners, according to the staff report.
The city’s existing method of gassing the ground squirrels in their dens with carbon monoxide every two weeks is mostly ineffective because the tunnels have multiple openings, allowing gas to escape, according to the staff report.
Another option is to catch the ground squirrels in non-fatal traps to prevent other animals from being harmed, but as the state does not allow live pests to be transported from the trap location, they would have to be dispatched on site, according to the staff report.
The final option considered by the Public Works Department would involve introducing a form of birth control into the ground squirrel population to keep them from reproducing in their June-through-August and December-through-February birth cycles — typically the best time to trap ground squirrels, according to the staff report.
But there is no approved birth control for ground squirrels available in the United States, according to the staff report.
Ultimately, the Public Works Department recommended using mechanical traps twice a year around breeding time to keep the population in check, though this would essentially mean shooting trapped ground squirrels on sight at the city’s parks.
Councilmember Marcia Guthrie recommended implementing a public education campaign on why park visitors shouldn’t feed the ground squirrels, while Councilmember Stacey Inman said she “doesn’t want the shooting of squirrels in our parks.”
Though the City Council turned the decision over to the Public Works Department, James said the method of removal still hasn’t been determined.
“The Public Works team is reaching out to industry professionals to determine what other cities are doing when responding to similar situations to what Pismo Beach is experiencing,” James said in an email. “As more information is gathered from this process it will likely shape what the future direction is.”
This story was originally published May 7, 2025 at 1:57 PM.
