SAND MINING RESOURCE & IMPACT ANALYSIS
San Francisco Bay and Suisun Bay, California

Coast & Harbor Engineering (CHE) performed coastal engineering analysis associated with sand mining activities at certain California State Lands Commission (CSLC) sand mining lease areas in Central San Francisco Bay and Suisun Bay. The goal of the analysis was to evaluate potential impacts of the mining activities and evaluate future sand resources. Sand mining was proposed to occur within designated CSLC lease areas over the next 10-year period. The study consisted of morphological analysis using hydrographic survey data, and hydrodynamic modeling and covered a wide spectrum of physical processes including tidal and river circulation, salinity, sediment transport, and bottom morphology.

Sand Mining Lease Areas in Central Bay (left) and Suisun Bay (right)

Two types of analysis included:

		Bottom Morphology Change and Mining Resource Evaluation: using hydrographic survey data: CHE conducted bottom morphology change analysis and mining resource evaluation based on evaluation of historical hydrographic survey datasets.
		Numerical Modeling: of currents, salinity and sediment transport/morphology: CHE evaluated impacts of the sand mining by comparison of hydrodynamics, salinity, and sediment transport/morphology for existing conditions and two after-mining scenarios using full-year Bay-wide 3D hydrodynamic simulations.

 

Left: Central Bay depth changes between 1997 and 2008 calculated from USGS multi-beam bathymetry data sets with sand mining location “worm tracks”. Right: Typical peak flood currents in Central Bay calculated with 3D hydrodynamic model.