May 20 2014 07:28 PM

There are way more of them than you think

Eric Bowlby
Eric Bowlby in Manzanita Canyon, one of dozens of canyons in the city that residents can explore
Photo by Joshua Emerson Smith

"I'm doing a story on San Diego's 13 canyons," I said over the phone to Eric Bowlby, executive director of nonprofit San Diego Canyonlands, hoping to cull some basic information. I had recently found a list of the canyons on the city's website, I explained. It was like summer-camp hiking for adults, with some trails leading straight to brewpubs. I wanted to tell people about these natural resources woven right into the urban landscape.

"Thirteen canyons!?" he said incredulously. "That's a good one. Thirteen canyons."

I could almost see him shaking his head on the other end of the phone. "Yeah, that's right," I said. "I'm doing a—."

"There's dozens of canyons in San Diego, dozens," he said with an abrupt chuckle. Despite, or perhaps because of, my ignorance, he agreed to meet me the next day to give me the full lowdown.

It turns out, San Diego has roughly 150 canyons, all part of a complex watershed. Rainwater flows from storm drains into the canyons, which are connected by a series of culverts and pipes, and eventually empties into the ocean.

Several decades ago, Bowlby got involved with the canyons as a clean-water activist. He advocated for proper maintenance of these open spaces, including restoration of native plant species, as a way to regulate pollution from storm-water runoff. With open space being paved over, canyons have become increasingly more valuable, not only for recreation, but also as a natural floodplain. 

"Water that's able to spread out and absorb into the ground drops its sediment and pollutants, and it gets broken down by vegetation and the soil ecology, and that cleans the water," Bowlby told me in his North Park home, out of which he runs the four-person nonprofit. Its website has links to resources for folks looking for canyon trails to hike, including the city's list of 13 canyons and Google Maps' list of all canyon trailheads in the area.

Staring at countless maps covering Bowlby's dining room, I thought about having recently hiked nearby Switzer Canyon. I had a blast traipsing through the lush trails, popping up on little neighborhood streets and diving back into the slightly damp nature that acted as an extended backyard for some area homes. 

However, I'd never imagined the environmental or political implications of these recreation resources. The idea that swimming warnings for the ocean 72 hours after a rainfall were connected to the health of our canyon system had completely escaped me.

"If you think about it on a citywide basis, with dozens of canyons scattered throughout each one of our watersheds, that's an opportunity to solve our water-quality problem, or certainly help it," Bowlby said. 

Throwing on some sunglasses, Bowlby suggested we drive over to Manzanita Canyon in City Heights—not one of the 13 listed on the city's website—and see firsthand some of the work his group had accomplished.

While the city's canyons could still benefit from significant maintenance, Bowlby's had some major victories in his time. "It could have been a lot worse," he said from behind the wheel of his Prius. "The bottoms of our canyons could be a mess with pavement, and the wetlands wouldn't have any chance to filter the urban runoff."

More than a decade ago, the city planed to pave over parts of the Manzanita Canyon floor to allow easier vehicle access for the public-utilities personnel who regularly do maintenance on buried water and sewer lines. At the time, Bowlby worked as the canyons campaign coordinator for the Sierra Club's local chapter, a position that eventually morphed into his Canyonlands project. 

Organizing residents, Bowlby secured an agreement with the city that limited the paving. Then, between 2007 and 2012, he successfully lobbied the city to dedicate as parkland 13,100 acres of identified open space, including several canyons.

Most recently, Canyonlands secured a $365,000 state grant to launch a canyon-enhancement planning program. The pilot project will be in of four City Heights canyons—Manzanita, Swan, Hollywood and 47th Street.

We pulled up to Azalea Park, which, he explained, connected to Manzanita Canyon by a wood staircase his group installed with the help of residents. Part of Canyonlands' mission is to organize people into "friends groups." Friends of Manzanita Canyon, he said, had been active for several years now.

"I'll bring this map with us," Bowlby said, stepping out into 90-degree heat.

"Yeah," I said. "We don't want to get lost."

"Just for the record, we're not going to freaking get lost," he grinned. "I'm bringing it so I can show you various things in the canyon for reference."

Walking across the park's grassy field, we descended the staircase, which sliced down into the canyon along a fence to the west, separating the trail from an embankment and Highway 15. Immediately, Bowlby sprung into action, identifying every plant species in sight as either native, such as mule fat or sumac, or nonnative, such as ice plant, or, as he referred to it "the green carpet of death."

"Look through here and you can see the ice plant, and you can see the erosion, too," he said. "It's totally destabilizing the soil."

At the bottom of the staircase, the trail opened up to a wide, brown canyon, flanked by bushes and tall trees and marked by a dry creek bed. As we hiked, he pointed out several native species that Canyonlands had planted and protected with rock circles.

"This is a native right here," he said. "This guy's doing good. This is buckwheat. He's doing really good."

The native plants have deeper roots and promote water absorption, he said. Nonnative plants tend to have shallow roots and create fuel for fire as they dry in the summer months. The fewer native species, the faster the nonnative invasive plants move in.

Turning a corner, we stumbled onto a rumbling utility truck and five guys getting ready to work on a broken water line. Bowlby wasted no time pointing out that the vehicle had been able to access the unpaved road. 

"Hey guys, what's up today," Bowlby greeted them.

"You see this hawk right here just yanked this little mouse right there," said one of the burly workers pointing up into a eucalyptus tree, which Bowlby pointed out was nonnative.  

"Oh, where is it?" asked another man.

"Right there in the tree," said the first. "He swooped down. Bam."

For a moment we all stood transfixed on this reddish hawk picking apart an afternoon snack. It was a gorgeous feeling to watch such raw nature right smack in the middle of City Heights. If these canyons could purify our storm runoff, they surely could, if perhaps only for select moments, also clear my mind.

Write to or follow him on twitter at @jemersmith.