Crossing from Rockridge BART station, a few pedestrians stop to notice a series of five large bronze reliefs outside Market Hall. Set into the sidewalk, they depict stepping stones surrounded by native fauna such as rainbow trout, frogs, newts and dragonflies.
More than just public art, the circles are a marker of the hidden waterway of Temescal Creek, which runs in a buried channel under the spot after being covered up decades ago.
"It was a really common practice," said Kristin Hathaway, a watershed specialist for the city.
The markers are part of a citywide project called "Creeks Beneath Your Feet." The bronze circles were designed by Oakland-based Wowhaus, the husband-and-wife team of Scott Constable and Ene Osteraa-Constable.
"The installations invite the public to interact with the artwork by walking across a symbolic creek or waterway, just as if crossing an actual body of water," the artists wrote in an email interview.
The markers cost $87,000 for design, fabrication and installation and were funded by the city's public art ordinance, which requires a 1.5 percent allocation from certain capital improvement projects and grant revenues.
After eliciting ideas from local communities, Wowhaus worked with Artworks Foundry in Berkeley to cast the markers. The stepping stones were cast from real stones and the original designs, reflecting Oakland's Art Deco and Craftsman design heritage, were first carved in clay.
"Community response has been really enthusiastic, and we love seeing people of all ages interact with the artwork," the artists wrote.
Other creeks marked by the designs are Arroyo Viejo at MacArthur Boulevard and 84th Avenue, Sausal at LaSalle Avenue and Mountain Boulevard, Lake Merritt and Lakeshore and Grand avenues in front of Peet's Coffee and Glen Echo at Bay Place and Harrison Street in front of Whole Foods.
"Creeks are a vital part of our watershed, and we were very inspired by the opportunity to create artwork that called attention to this vital yet often invisible component of the watershed," the artists said.
There are more than 15 main creeks and 30 tributaries in Oakland, with about 100 miles of open waterway.
"Occasionally we will discover a parcel or property where we didn't know there was a creek there," Hathaway said.
Temescal Creek, like many other creeks in the city, was covered up and channeled into pipes as a way to avoid flooding, a popular urban planning practice all through the 20th century.
"You wanted to move the water out of the city as soon as possible," said Hathaway.
Temescal Creek collects water from smaller streams all over the Oakland hills, enough water so that it runs year-round. The creek flows through Emeryville to the bay, and in fact an open section, with concrete banks, can be seen in the Bay Street Mall.
The majority of Temescal Creek is invisible, however, though there are still sections of it above ground, including in Garber Park and by Lake Temescal. There's also a pleasant stretch of creek near the Department of Motor Vehicles on Claremont Avenue -- only it's not real.
"That's actually a faux creek," Hathaway pointed out.
The water runs under the landscaped creek bed, and a portion is pumped up during summer months.
Since the heyday of creek burying, increased interest in restoring creeks has led to uncovering the channels, known as daylighting. But releasing covered creeks isn't an easy task, Hathaway said.
"Daylighting is really tricky, because you have to have the space to do it and you have to have property rights," she said.
Instead, the city often focuses on restoration of existing creek beds and replanting with native plants.
So it's unlikely more of Temescal Creek will see the light of day, but the bronze markers will serve as a reminder of what still lies beneath city streets.