[Fosc] ARTICLE on taming storm runoff, preserving creeks
edward.goehring at gmail.com
Sat Jan 2 12:09:22 PST 2010
In El Cerrito, taming runoff
Joe Eaton,Ron Sullivan
Friday, January 1, 2010
Although the small East Bay city of El Cerrito keeps a low profile, it's the home of a quiet revolution in urban landscaping.
Following the lead of Portland and Seattle, El Cerrito is managing storm water with low-impact design features like bioswales and
rain gardens, in which plants help remove pesticides, petrochemicals and heavy metals from runoff before it enters the soil. The
idea, as Brock Dolman of the Occidental Arts & Ecology Center's Water Institute puts it, is to "slow the water down, spread the
water out, and sink the water into the land."
A recent tour sponsored by the San Francisco Estuary Partnership and the Urban Creeks Council showed off El Cerrito's new City Hall
with its bioswale plantings, creek restoration projects and locations of planned sidewalk rain gardens. In December, we visited
several of the stops with Lisa Owens Viani of the estuary partnership and Ann Riley of the Waterways Restoration Institute.
According to Riley, the greening of El Cerrito began in 1996 on a culverted stretch of Baxter Creek. When an underground storm drain
collapsed, Mori Struve, the city's director of Public Works at the time, decided it would be more cost-effective to dig up the
culvert and remove it than to replace it. The Urban Creeks Council applied for a California Department of Water Resources grant to
daylight and restore the creek. Riley's nonprofit group brought in the East Bay Conservation Corps to plant willow and dogwood
cuttings along the creek and create what hydrologists call a step-pool channel with strategically placed rocks and boulders.
'Natural creek channel'
"The New Year's Flood of 1997 picked up boulders and cobbles and distributed them through the channel, creating a natural creek
channel in one storm," Riley said.
Now the heart of Poinsett Park, the stream corridor is lush with alders, bigleaf maples and coffeeberry shrubs. It's alive with
birds; an Urban Creeks Council study of five East Bay restoration sites found the greatest avian diversity along this 250-foot
section of creek. "Even small projects provide valuable habitat," said Owens Viani. The vegetation also absorbs and filters storm
water from the surrounding urban neighborhood at a fraction of the cost of a brick-and-mortar treatment plant.
That success inspired a more ambitious project farther downstream on Baxter Creek, in a trash-strewn open area near San Pablo
Avenue, at one point slated for takeover by a nearby Lucky store.
"Friends of Baxter Creek fought development here for years," Owens Viani said. The space for Gateway Park was saved, thanks to
funding from the Coastal Conservancy and the city of El Cerrito. Drew Goetting's Restoration Design Group was hired in 2004 to
remake the creek.
"We removed the existing channel and started from scratch," Goetting said. "We created a broad basin that will hold quite a bit of
floodwater in high events and provide the habitat benefits of a floodplain."
Live willow cuttings were planted to stabilize the creek banks. Once the site of homeless encampments, Gateway Park is now heavily
used by school groups. Western bluebirds winter here; nest boxes might encourage them to stick around into the breeding season.
Creek restoration is only part of the story. The city is also creating rain gardens to capture and filter runoff from paved
surfaces. Melanie Mintz, El Cerrito Environmental Services division manager, showed off the new green City Hall, for which LEED
certification is pending. The handsome building is fringed with bioretention areas, and linear bioswales border the parking lot.
Most of the plants are California natives: marsh plants like sedges, reeds and horsetails in the bioretention area, accented by
redbud, vine maple, silktassel, coffeeberry and California rose. On the north side, recycled water flows in a fountain with
hand-laid cobbles that evokes the East Bay's creeks.
Mintz said the old City Hall site's impermeable pavement was prone to sheet flooding: "We didn't even have storm drains here." With
an opportunity to rebuild, El Cerrito decided to go the low-impact route rather than use underground vaults for rainwater catchment.
Permeable rock underlies 18 inches of soil with high organic-matter content.
"It's a deeper-than-natural profile that absorbs more water," Mintz said. "We exceeded the new storm water requirements before they
even took effect."
The next step, within a month or so, will be installing sidewalk rain gardens along two blocks of San Pablo Avenue. The gardens,
filled with sandy loam, will catch runoff from the street and sheet flow from nearby commercial parking lots, and will feature
native plants similar to those at City Hall. Subdrains at the bottom of each unit will feed water into the nearest storm drain.
In freeing its creeks and depaving its sidewalks, El Cerrito is building what Owens Viani calls "a string of beads on a green
necklace." It's a mix of aesthetics and practicality, storm-water control and habitat creation - and a way of making one Bay Area
city more resilient to climate change.
"Slow It, Spread It, Sink It": Video featuring Brock Dolman on San Francisco Estuary Partnership's Web site,
Joe Eaton and Ron Sullivan are naturalists and freelance garden writers in Berkeley. Check out their Web site at
www.selbornesurveys.com or e-mail them at home at sfchronicle.com.
This article appeared on page L - 2 of the San Francisco Chronicle
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