Curb-Core Rain Garden Demo
Greening a Street, One Step at a Time
By Annie Stuart
Kathryn Shedrick is a woman on a mission.
An inaugural Cool Block leader with Cool Petaluma, Kathryn lives on 5th Street in Petaluma, which became a Slow Street during the Covid pandemic. That means it was restricted to local traffic with a speed limit of 15 mph. “People really enjoyed that,” she said, especially since 5th Street is so wide and flat that it practically begs people to drive too fast.
Given the street’s bikeability, the City first suggested designating it as a “Bike Boulevard,” but Kathryn lobbied for “5th Street Neighborhood Greenway” as a way to inspire more greening with native trees and plants. She loved that trees could not only add shade, habitat, and pollinators, but would beautify the street, improve health, help ease runoff, and slow traffic – all assets of Complete Streets, a city planning concept she had started researching.
And so it became known as the “5th Street Neighborhood Greenway.”
Getting around “roadblocks”
Fifth Street was bereft of trees, so Kathryn’s first goal was to plant many more of them, after conversations with ReLeaf Petaluma, which engages the community to plant and steward native trees. “I soon discovered that the sidewalk strips were too narrow to accommodate larger shade trees, which is what we really wanted,” she said.
Not easily deterred, Kathryn studied alternatives and found that cities sometimes create a bump out, or curb extension. The sidewalk strip can then accommodate larger trees, which lessens the amount of pavement, adds more soil, and slows traffic. Kathryn consulted with Pete Gang, architect and co-founder of Safe Streets Petaluma, who had already drafted a Greenway design that included planted bump outs and greening to improve street safety.
“The bump out would allow planting of native habitat,” she said. “In addition, curb cuts could be added at both ends of the bump out, capturing stormwater, which would water the trees and eventually end up as ground water, rather than gushing down the street.”
Unfortunately, the bump out bumped into other roadblocks. Although the City loved the idea of greening streets with trees, she said, it lacked the funds or bandwidth to implement them at scale and didn’t have an Urban Forestry Manager to oversee tree planting and maintenance. Although budgets remain tight, the City is planning to include street trees in its St. Francis Drive project and is working on a vision for Petaluma's Urban Forestry Management Plan. For now, they have added painted bump outs to help slow traffic.
With a little more help from friends
Kathryn and current Cool Block leaders – Maria Ray and Kim Nielsen-Glynn – decided to focus instead on what they could do to help make the street greener and more sustainable. Their dream was to make the 5th Street Neighborhood Greenway a showcase for a native garden – a community-led demonstration project, hopefully one of many to come. (Maria and Kathryn collaborated on a version of the Greenway in the annual gingerbread competition and won first place in the Petaluma Pride category!)
To help get the project off the ground, Kathryn applied for a one-time, $500 micro grant for small community demonstration projects. It was offered by Urban Chat – a Petaluma nonprofit that informs the community about city planning.
But another idea began to germinate in April of 2024. Sebastian Bertsch, a project strategist with Sherwood Design Engineers, approached the 5th Street team with the idea of creating a curb core rain garden. It diverts polluted stormwater into the sidewalk strip – slowing, spreading, and sinking it into the soil, where it can naturally irrigate native plants. Sebastian calculated angles and drew up drawings for boring holes in an existing sidewalk to create a rain garden and capture runoff – and helped shepherd the project through the application process.
With input from Daily Acts, a sustainability nonprofit with expertise in water management, Kathryn and other neighbors identified a few ideal properties for the installation, but landed on creating one in front of Maria’s home. The grant money covered a portion of the project, while Maria paid the remaining $1,000. She added her own whimsical touch to the project. “In December, she created tableaus with dinosaurs wearing Santa hats!” said Kathryn. But when the rain fills the pools, the rubber ducks come out to float, said Maria. “When it starts to rain, I break out the ducks and watch them sail around the pond! On sunny days, people ask, ‘Where are the ducks?’ and I say, ‘Waiting for rain!’”
A sign at the site reads, in part, This simple green-engineering retrofit helps mitigate flooding; protects our watershed; provides climate-smart irrigation; and creates habitat for local birds, bees, and butterflies. It is just one of several community-led climate solutions inspired by Cool Petaluma.
“We want to let people know that they could have one of these in front of their house,” said Kathryn. Not a bad idea, especially given that a nearby street corner with poor drainage turns into a lake during atmospheric rivers, with the polluted runoff ultimately ending up in the Petaluma River.
More to come
Because she handed over the Cool Block community-building reins to others, Kathryn now calls herself a Cool Block emeritus. The fun-raising part is clearly in good hands if Maria’s plan for a summer hoedown is any indication! “Spreading joy and caring for neighbors and community really matters to me,” said Maria, “especially since it’s hard to make change on a global level.”
Not about to rest on their (Bay?) laurels, Kathryn and the Cool Block team have more plans in mind. They created a garden committee, called “Green Thumbs.” One initial idea was to help transform a neighbor’s grass lawn into a drought-tolerant, native garden. Kathryn’s first thought was to do this for an older neighbor who she makes a meal for once a week. The project sounded a little too daunting to him, so they shifted gears and offered to plant trees instead.
A native garden tour is also on the docket, she said, pointing out the California lilac in a neighbor’s yard as we walked down the street. The hope is to just keep greening, just keep greening…. The team will help with cost estimates for mulch and plants, and provide physical labor for neighbors’ projects. Fortunately, someone on the block can help with irrigation – he knows how to retrofit a sprinkler head into drip irrigation.
Food forest royale
Before leaving 5th Street, I was sure to get a quick look at Kathryn’s own green creations, including a front-yard rain garden and back-yard food forest, inspired by Daily Acts workshops and yard tours.
“We had literally just finished designing our garden,” she said, “when I took a tour of Trathen Heckman’s yard.” (Trathen is the Executive Director of Daily Acts.) “I called the designer and said, ‘I want a food forest instead!’” Smart, since someone clearly likes fruit: Although not everything is yet mature and bearing fruit, you’ll find blackberries, blueberries, a weeping Santa Rosa plum, lemon, nectarine, grapes, pineapple guava, apples, peaches, passion fruit, and oranges! Surrounded by native grasses, yarrow, buckwheat, and milkweed. “The only non-natives are a couple of Ginkgo trees,” she said.
Her plan is to either put a little free farmstand out front or have gleaners come and harvest the extra bounty to be shared with others.
A woman on a mission? Clearly! A force of – and for – nature? Without a doubt.