City Puts Squirrel and Gopher Abatement Program on Hold

City Manager Steve Mermell has put a halt to the city’s participation in a county program to abate gophers and squirrels.

“Apparently, we were part of a program with the county to address ground squirrels and gophers which cause damage to parks and athletic fields,” Mermell told Pasadena Now. “The program would include the use of poison to reduce populations of the rodents. Certainly, we want our parks and athletic fields in good shape and we spend the public’s money maintaining them, but the use of poison is a concern because the animals who ingest it are often in turn consumed by other wildlife causing significant damage to those populations.”

The overpopulation of ground squirrels and gophers in areas like Brookside Golf Course and Hahamongna Watershed Park can become problematic if left unchecked, according to a city staff report in a recent Parks and Recreation Commission agenda.

According to Brenda Harvey-Williams, director of the Parks, Recreation and Community Services Department, the commission referred the matter to its maintenance committee for further discussion. According to Harvey-Williams, no rodenticides have been used in city parks since 2019.

“Based on the city manager’s direction, we have no plans to resume the use of rodenticides,” Harvey-Williams said. “We will explore the use of alternative methods of controlling the squirrel and gopher populations.”

According to documents included in the agenda, the city’s parks division had partnered with the Los Angeles County Department of Agriculture to manage the overpopulation of squirrels and gophers.

The program used a variety of methods to catch the rodents, including bait traps and diphacinone, an anticoagulant bait that comes in pellet, liquid and powder forms.

The city’s efforts focused on Brookside, Hahamongna Watershed and Oak Grove parks. Defenders Parkway, Eaton Blanche Park and Victory Park and were handled by Los Angeles County Department of Agriculture certified applicators.

“Park staff do not engage in any chemical pest control [such as fumigants or bait stations]; however, efforts have been made to explore alternative methods to control overpopulation,” according to a past staff report.

Pocket gophers and ground squirrels are classified as nongame mammals by the California Department of Fish and Game.

The populations may be controlled at any time by legal means.

Pocket gophers can inflict damage by invading gardens and lawns as well as agricultural crops.

They can damage trees and also gnaw on and damage plastic water lines and lawn irrigation systems.

Their mounds can interfere with and damage lawn mowing equipment.

The mounds also provide a starting place for invasive weeds in landscape and agricultural areas.

Pocket gopher burrows can weaken ditch banks and canals. Irrigation water diverted through their tunnels can be carried away and can lead to soil erosion.

“The overpopulation of these pests can pose a public health concern due to the diseases they may carry,” city staff wrote in a report included in the agenda. “Some of the diseases that could be transmitted to humans include typhus and bubonic plague. Additionally, the overpopulation of these pests can damage infrastructure, habitat and maintenance equipment.”