USGS - science for a changing world

San Francisco Bay Delta

SF Bay Projects

San Francisco Bay Projects

Corte Madera Creek suspended-sediment dynamics

Contact: Maureen Downing-Kunz, Hydrologist, mdowning-kunz@usgs.gov

As sediment supply from the Central Valley to San Francisco Bay (Bay) decreases, smaller adjacent tributaries may play an increasing role in sediment supply to the Bay. Sediment supply is continuously monitored in some Bay tributaries using traditional sediment gages located upstream of tidal influence. Tidal interactions near the mouth of a tributary, however, can trap portions of this measured sediment supply in the channel, thus reducing supply to the Bay. Additionally, during periods of low stream discharge, suspended sediment from the Bay can be transported to and deposited in the tidal reaches of these tributaries, further reducing suspended-sediment concentrations in the Bay. Given these uncertainties, we investigated suspended-sediment dynamics in Corte Madera Creek (Marin County, CA). Using moored acoustic and optical instruments, we observed water velocity and suspended-sediment concentrations continuously.

Relevant work:


Salinity and temperature variability in the San Francisco Bay

Contact: Greg Shellenbarger, Research Hydrologist, gshellen@usgs.gov

One event from the Natural Experiment at the Wickland Oil Pier

Diagram of one event from the Natural Experiment at the Wickland Oil Pier. (A) An abrupt increase and subsequent decrease in Q during a period of low flow, (B) the corresponding decrease and subsequent increase in salinity that results from the change in Q. The subscripts "Rising" and "Falling" refer to the hydrograph (Shellenbarger and Schoellhamer, in review)

Average annual salinity at Wickland Oil Pier vs. average annual QOUT.

Average annual salinity at the upper sensor at Wickland Oil Pier vs. average annual QOUT for the same years. The linear regression was fit to data from 1987–96 (closed circles). The year 1997 (+) had more than 50% of the data available for the year, but this site was missing most of the wet-season data for the year. This biased the salinity–flow relationship, so this point was not used for the regression (Shellenbarger and Schoellhamer, in review).



*Pending submission

Relevant work:

Shellenbarger, G.G., and Schoellhamer, D.H., in press, Continuous salinity and temperature data from San Francisco Bay, California, 1982-2002: trendsand the freshwater-inflow relationship. Journal of Coastal Research.

Buchanan, P.A., 2009, Specific conductance and water temperature data for San Francisco Bay, California, for Water Years 2006 and 2007: Interagency Ecological Program Newsletter, v. 22, no. 3, p. 34-39.


Tidal margin suspended sediment fluxes

Contact: Greg Shellenbarger, Research Hydrologist, gshellen@usgs.gov

*Pending submission

Relevant work:

Lionberger, M.A., and Schoellhamer, D.H., 2006, A box model of a series of salt ponds in the Alviso Salt Pond Complex, South San Francisco Bay: Proceedings of the South Bay Science Symposium, June 6, 2006, San Jose, California, p. 15.

Schoellhamer, D.H., 1996, Factors affecting suspended-solids concentrations in South San Francisco Bay, California. Journal of Geophysical Research, 101 (C5), p. 12087-12095.

Shellenbarger, G.G., Wright, S.A., and Schoellhamer, D.H., 2011, Sediment flux in the southern reach of San Francisco Bay: implications for habitat restoration: Proceedings of the South Bay Science Symposium, Menlo Park, Calif., February 3, 2011.


San Francisco Bay suspended sediment monitoring

Contact: Maureen Downing-Kunz, Hydrologist, mdowning-kunz@usgs.gov

Suspended sediment is an important component of the San Francisco Bay. It is essential for the creation of tidal wetlands, it is a vehicle for contaminant transport, it limits light availability for photosynthesis, and it affects shipping ports and navigation in the estuary. To better understand sediment supply and transport processes, suspended sediment concentration (SSC) is monitored continuously at five sites in San Francisco Bay. In situ optical sensors record water turbidity at two sites in Suisun Bay, two sites in Central San Francisco Bay, and one site in South San Francisco Bay. To relate water turbidity to SSC, water samples are collected periodically and analyzed for concentrations of suspended sediment. These results are used to calibrate the output of the optical sensors, thereby providing continuous records of SSC. After nearly 20 years of monitoring, this long-term dataset allows further understanding of sediment transport processes at tidal to annual time scales.

Relevant work:

Buchanan, P.A., and Morgan, T.L., 2010. Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2007: U.S. Geological Survey Data Series 476, 30 p.

Schoellhamer, D.H., 2009, Suspended sediment in the Bay: Past a tipping point: The Pulse of the Estuary: Monitoring and managing water quality in the San Francisco Estuary, San Francisco Estuary Institute, Oakland, Calif., p. 56-65.

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://ca.water.usgs.gov/projects/baydelta/bay.html
For Page Information: Send Us a Message
Page Last Modified: Thursday, 29-Dec-2016 23:06:32 EST