NR 2007-06
February 7, 2007

Contact: Ed Wilson
Mark Oldfield
Don Drysdale
(916) 323-1886


Some Areas Face Shortfall of Locally Available Construction Material

The report and map are available here.

SACRAMENTO – The Department of Conservation’s California Geological Survey has released a new report and map that discusses aggregate supply and demand. It is designed as a tool to help local governments with land-use planning, especially as in regards to future infrastructure needs.

“The intent of this map is to give decision-makers a picture of where they stand with respect to a key resource,” DOC Director Bridgett Luther said. “Land use is a local decision. However, our economy and way of life depend to no small extent on our infrastructure, which relies upon aggregate and concrete. Local government should consider the issue of access to aggregate resources when planning for growth and development.”

The report – an update of a 2002 release -- compares the anticipated 50-year demand for construction grade aggregate resources to the amount of resources currently permitted for mining by local lead agencies in 31 study areas throughout the state.

The map shows four areas with less than a decade’s worth of permitted resources:

¨ Sacramento County (67 million tons permitted, 733 million tons of projected demand).

¨ Fresno County (71 million tons permitted, 629 million tons of projected demand).

¨ North San Francisco Bay (49 million tons permitted, 647 million tons of projected demand).

¨ North Tulare County (12 million tons permitted, 117 million tons of projected demand).

All told, 10 study areas have permitted resources covering less than a quarter of their projected needs.

Only six regions have permitted reserves covering 50 percent or more of their future needs. The Yuba City-Marysville region is the only area projected to meet 100 percent of its 50-year demand.

Other regions with a seemingly adequate permitted supply of aggregate in the near future include: Barstow-Victorville, Eastern Merced County, Monterey Bay and Palm Springs.

The regions with the highest projected future need for aggregate are South San Francisco Bay, San Gabriel Valley, Temescal Valley-Orange County, Western San Diego County and San Bernardino. Each of these regions is expected to utilize more than a billion tons of aggregate by 2056.

“Aggregate is a critical component of many types of construction projects,” State Geologist John Parrish said. “While there’s a significant amount of the resource in the ground in most areas, local jurisdictions have not permitted miners to extract it, for various reasons. Ultimately, aggregate shortages can lead to higher construction costs.”

Construction-grade aggregate, as defined in the report, is sand and gravel or crushed stone that meets specifications for use in “portland cement concrete aggregate” or “asphaltic aggregate.” It is used in the construction of houses, commercial and public buildings, highways, roads, bridges and other structures. Having a local supply of permitted aggregate is important because the cost – which currently ranges from about $7-$22 per ton at the plant site for the highest grade – can significantly increase as haul distances become greater.

Construction sand and gravel is the leading non-fuel mineral commodity produced in the state as well as the nation. Californians consumed 235 million tons of construction-grade aggregate in 2005 – about 6½ tons per person. On average, 229 tons of aggregate are used in the construction of one house.

“Currently, California has about 4.3 billion tons of permitted resources,” Parrish said. “In the next 50 years, the state is projected to need approximately 13.5 billion tons of construction grade aggregate. This figure does not account for accelerated construction programs as a result of major bond initiatives, or from reconstruction following a major, damaging earthquake.”

In addition to studying and mapping mineral resources, the Department of Conservation ensures the reclamation of land used for mining; promotes beverage container recycling; regulates oil, gas and geothermal wells; studies and maps earthquakes and other geologic phenomena; and administers agricultural and open-space land conservation programs.