Petaluma staff propose lane reduction, bioswales and new street trees for Caulfield Lane

Petaluma Public Works outlined a Caulfield Lane paving project planned for 2027 that would rehabilitate sections of the roadway, convert some intersections to roundabouts and reduce vehicle lanes to create protected bike lanes and a planting strip intended for street trees and potential bioswales. Project manager Bjorn Griebenberg said construction is planned to start next spring and that staff are seeking species recommendations from the Tree Advisory Committee as the landscaping design is being finalized.

Griebenberg described the project limits (Peyran Street to Garfield Drive) and identified two roundabout locations and two long linear stretches as planting opportunities. He said the team is recommending a lane reduction from two vehicle lanes each direction to one, protected bike lanes with a 7-foot landscape strip, and stressed that Caltrans mitigation funds might enable the installation of bioswales — with Caltrans potentially covering installation and 20 years of maintenance. "So there is potential for Caltrans to fund these bioswales," he said.

Committee members pressed staff for specifics on spacing and soil: staff estimated about 1,100 feet of planting opportunity along Saint Francis to South McDowell and roughly 600 feet between Park and Cronella (directional figures were used to simplify planning). Member Eric McKee and others urged that soil conditions and long-term survival be prioritized when selecting species, noting that soil replacement will be required where swales are installed. "If we do go to swales . . . you would see a lot of the native soil removed and replaced with something that takes on water more effectively," Griebenberg said.

The committee also discussed maintenance trade-offs for protected bike lanes and leaf litter, and queried irrigation sources: Griebenberg said no recycled-water connection exists now and that, if irrigated, plantings would rely on potable water unless future recycled-water connections become available. Chair Patrick Shand warned of root-rot risk where trees remain saturated and recommended designing for aeration and long-term drainage if bioswales are used.

Staff asked the committee to provide species guidance within about a month as the design team needs to finalize landscaping; Griebenberg offered to return to the committee or to work with members between meetings. He also shared a project page for public tracking: cityofpetaluma.org/caulfieldeli. Next formal steps include award of a construction contract (late 2026 or early 2027) and anticipated ground-breaking in spring 2027.