When mining ceases, quarries bloom

What happens when mining quarries reach the end of their useful lives? The Inland region's highest-profile answer is the rebirth of former sand-mining pits into the Dos Lagos commercial and residential development in Corona.

Elsewhere in the state, former mining pits and quarries are being turned into industrial parks, housing developments, agricultural fields and nature preserves.

California law states that no mining operations can start until a company has submitted an environmentally sound reclamation plan to the state. All of the more than 1,400 California mines and quarries now in operation will eventually undergo site restoration -- so they don't, for instance, leave an eyesore once mining ceases.

"It's valuable real estate if it can be back-filled and brought back to its original grading," said Jim Pompy, a mine reclamation manager with the California Department of Conservation.

The question for each locale is what form that reclamation will take.

In the Inland region, some aggregate surface mines -- used to collect materials for road and building construction, such as gravel, sand, limestone and granite -- will go back to nature rather than into commercial redevelopment.

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Steven Lewis / Special to The Press-Enterprise

The Dos Lagos site in Corona had to be designed to restore land that had been mined, prevent the spread of dust and protect endangered species.

'Revegetating the Slopes'

In an area spanning portions of Redlands and Highland north of Interstate 10, aggregate quarries mined by Cemex USA and Robertson's Ready Mix, two construction-supply firms with operations throughout the region, will become natural open space and habitat-preservation land as part of the Santa Ana River Wash project.

The quarries remain in operation, but a plan is in place to restore them. Jennifer Borgen, a spokeswoman for Houston-based Cemex USA, said a time frame on the reclamation has not yet been set.

"Once the site is ready for reclamation, we will work with biologists and environmental specialists on this plan," Borgen said. "It will include revegetating the slopes with native plant species to what existed before the quarrying."

Experts say that most mine reclamations in California consist of filling, grading and preserving land rather than developing it commercially. That's in large part because of the cost and time involved in getting approvals, on top of higher land and building costs compared with the rest of the nation.

"People in business don't like uncertainty, and they don't like complexities. But I think that's changing in many ways," said developer Ali Sahabi, who purchased more than 500 acres of quarry land in the early 1990s that eventually became the Dos Lagos master-planned community in Corona.

An open-air shopping center, called Promenade Shops at Dos Lagos, opened there in October. Bordered by Temescal Canyon Road and Interstate 15, the development also has a hotel, homes and office buildings in the works.

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Lou Hirsh / The Press-Enterprise

A gravel quarry land between Redlands and Highland will eventually become part of the Santa Ana River Wash conservation project.

The increasing focus on environmentally friendly building is leading other developers to get more creative with former quarry sites.

In places such as California, recent building booms have created demand for new aggregate mines, and those mines will eventually require new uses once they have been depleted.

"Very seldom do you see people just filling it back in," said William Langer, a research geologist with the U.S. Geological Survey in Denver, referring to national trends. "If you've built roads and other things with it, there isn't anything to put back in."

Instead, Langer said, communities around the globe are finding other uses for them. Several American cities have turned quarries into water reservoirs, natural tide pools and nature preserves.

In the Netherlands, one community turned an quarry into an outdoor musical amphitheater.

Funding

Most of these projects require local-government or private funding. In California, state-issued community redevelopment funds usually aren't applicable to quarry locations. John Shirey, executive director of the California Redevelopment Association, said about 80 percent of the 760 redevelopment projects around the state are in urbanized areas where a quarry would not be found.

But Shirey said some communities have the geography and an economic history geared toward mining that justifies the granting of state assistance.

An example is Irwindale, about 20 miles east of Los Angeles in the San Gabriel Valley, where a former quarry in the civic center area was rehabilitated into a 125-acre, 2.2 million-square-foot industrial park.

According to the redevelopment association, the assessed value of the Irwindale land increased from $3 million before the rehabilitation to more than $63 million afterward. The industrial park has generated more than $500,000 in sales taxes since its 2005 opening.

Dos Lagos

In Corona, Sahabi said the quarry property was assessed at $5 million before he developed Dos Lagos, and the figure is now $960 million.

The developer the project, conceived about 11 years ago, took getting an annexation approved, as well as obtaining numerous other city, state and federal approvals over the past four years.

The project also had to be designed to restore lands that had been mined, prevent the spread of dust and protect endangered species in the area surrounding Temescal Creek.

Sahabi said he modeled the rehabilitation on successful quarry renovations in Texas because there were few in California when he was planning the project. He said it was worth the time and investment to create an environmentally sustainable project, and other developers could do the same with Inland quarry areas.

"We need to think long term, and sometimes the fixes we're looking for are not easily found," he said.

Reach Lou Hirsh at 951-368-9559 or lhirsh@PE.com