San Diego is facing a shrinking supply of sand and gravel as quarries are closed down and no new ones are permitted.
Granite Construction has worked for six years on a proposal to open a new quarry between Rainbow and Temecula, just north of the San Diego County line. But today, after three full days of public hearings, Riverside County Supervisors voted three to two to reject the proposed Liberty Quarry.
They cited air quality concerns, increased truck traffic, damage to the Temecula wine country’s tourist industry and respect for the Pechanga Band. The Pechanga, one of the wealthiest tribes on the West Coast, say the mountain the quarry would hollow out is sacred.
Riverside Supervisor Bob Buster was critical of San Diego County’s board for their silence on the subject, since San Diego would be a major consumer of the rock produced in the open face mine.
San Diego County supervisors have not approved a new mine for decades and the number of quarries in San Diego has shrunk from 48 in the 1980s to just 16 now. If no new quarries are approved, the number will fall to seven by 2030. Future shortfall will depend on demand for things like new road construction.
The California Geological Survey says San Diego already pays the highest price in the state for aggregate for new roads.
A 2011 report by SANDAG and Caltrans suggests there is no shortage of suitable rock in San Diego County’s geology. There are 1,000 potential sites for mines. However, other alternatives include dredging reservoirs, recycling construction materials and importing more sand from places like Mexico by barge.