Sand miners should not be allowed to increase the amount of sand they remove from San Francisco Bay and the Delta, Baykeeper warned state regulators this month. This is based on recent research indicating sand mining likely contributes to erosion and other damage to the Bay and Pacific shoreline.
Baykeeper urged the California State Lands Commission to protect the Bay from excessive sand mining through our comments on the San Francisco Bay and Delta Sand Mining Revised Draft Environmental Impact Report (DEIR). Along with other scientists, citizens and environmental groups, we contend that the current proposal would permit sand mining to proceed in the central Bay and Delta at an entirely unsustainable level.
Sand from riverbeds and shorelines in the Delta is carried through waterways and deposited in the Bay through a natural process of sedimentation. Sand mining operations dredge the floor of the central Bay to collect this material to make concrete.
However, recent United States Geological Survey (USGS) research indicates that sand mining operations remove more sand from the Bay than enters from the Delta. According to Dr. Patrick Barnard of USGS's Santa Cruz office, ongoing sand mining “could result in significant erosion and other geomorphological impacts to areas within and outside San Francisco Bay.” It is likely that unsustainable rates of sand extraction in the Bay and Delta contribute to significant erosion at Ocean Beach, which is normally replenished by Bay-Delta sand.
While sand mining is an important industry in the Bay Area, it should not result in a net loss of mineral resources. Under the current proposal, sand extraction could increase by 50% of the 2002 - 2007 average. These years were a period of high levels of construction activity that are unlikely to be repeated in the near future, resulting in lower demand for concrete. Until scientists and regulators can agree on a sustainable rate of mineral extraction, sand miners should not be permitted to increase their allotment over the next ten-year lease period.
Baykeeper will continue to follow the state of sediment science in the Bay and insist that its mineral resources are managed in a sustainable fashion.