"We don't have a lot of construction going on now in Ventura County," she said. "So will the material end up being used to widen Highway 126, or will it be used to build houses in Valencia?" She said the supervisors will look closely at that question, which will also be addressed in the environmental study.
The sand deficit has not begun to show on area beaches, despite four decades of dams and intensive excavation, said oceanographer Bailard.
"The reason is that the delta at the mouth of the Santa Clara has made up the deficit," he said. The delta formed after floods in 1969 brought huge deposits of rock and sand down the river. It has helped stabilize beaches that are down the coast from the river mouth near McGrath State Beach, he said.
"But we don't really know how long it will last or when it will run out of sand," he said.
"You have a classic case of competing priorities here," Bailard said. "There is clearly a need for sand mining and construction materials, so what's more important? That's what the supervisors will decide."