Quarry owner and Zoo team up to create wildlife preserve

By: KEN MA - Staff Writer | Wednesday, September 22, 2004 11:38 PM PDT ∞

SAN MARCOS ---- Inside a quarry bustling with dump trucks and conveyer belts lies a parcel of hilly terrain that is home to the endangered California gnatcatcher. The 86-acre parcel is covered with coastal sage and California bunch grass and is home to tiny, long-tailed birds called gnatcatchers, coyotes, red-tailed hawks, owls and San Diego coast-horned lizards.

The 253-acre quarry that sits near homes and businesses just southeast of Cal State San Marcos has never been developed. The quarry's owner, Hanson Aggregate's Pacific Southwest Inc., and San Diego Zoo officials, said Wednesday they want to keep it that way forever.

Hanson and the zoo are joining forces to preserve the area as a permanent wildlife habitat area. Zoo officials said they plan to start the effort within the next several weeks by sending scientists to survey and sample the site, situated at the southern end of Twin Oaks Valley Road.

"You need to be vigilant about these habitat programs," said Jeff Opdyke, the zoo's conservation manager.

The area, atop a grassy knoll, was set aside for conservation as a condition for Hanson to operate its quarry, which produces about 600,000 cubic yards of granite annually, City Manager Rick Gittings said. Operating since 1989, the quarry produces rock that is sold to builders for roads, schools, hospitals and sidewalks. It will operate until 2008.

Hanson's wildlife conservation area is among at least six other conservation areas in San Marcos, Gittings said.

Marvin Howell, the company's director of land-use planning, said Hanson and the zoo will provide maintenance for the site, which will not be open to the public. They said they will also create programs to teach the community about native wildlife and conservation efforts.

"The creation of the (wildlife) corridor is going to be very beneficial to the city of San Marcos," Howell said.

Michael Beck, the San Diego County director of the Endangered Habitat League of Southern California, said establishing such conservation areas was vital to the survival of native plants and animals, whose natural habitat is continually shrinking by development.

"It's important we have these areas so wildlife can feed, breed, hunker down and disperse," Beck said. "We are very pleased that they (Hanson) were progressive enough to get us to this point."

Threatened species, such as the gnatcatcher ---- there are fewer than 10,000 left in Southern California ---- need conservation areas because 80 percent of their habitat has been wiped out over the years, Beck said.

"If these habitat areas do not succeed, these birds will go extinct," he said.

The 86 acres at Hanson's quarry are also important to the California bunch grass, Beck said, because the bunch grass, along with other native grasses, has been replaced by non-native plants in more than 90 percent of the county.

Opdyke said zoo officials hope to attract more gnatcatchers to the area and help expand the bunch grass population.

"It (the bunch grass) is kind of a rare habitat," Opdyke said. "We would like to encourage development of that."

Zoo officials plan to monitor the site on a weekly basis, collect samples, and eliminate weeds and other plants that encroach on native species, he said.

Although the site is off-limits to the public, hiking trails may eventually be built after the quarry closes in 2008, he said.

Following the closure, Hanson plans to sell the rest of its quarry to developers to build homes, roads and a park.

Discovery Hills resident Dave Mitchell, who lives near the quarry, said the conservation area is needed to keep a balance between development and wildlife preservation.

"We should take necessary action to assure that we keep a diverse ecosystem, and yet still keep in mind that there is a need for more homes," Mitchell said.

Contact staff writer Ken Ma at (760) 761-4408 or kma@nctimes.com.