Executive SummaryThe Bureau of Reclamation (Reclamation) operates the Central Valley Project (CVP), one of the nation’s largest water projects. Reclamation has an ongoing need to improve the scientific basis for adaptive management of the CVP and, by extension, joint operations with California’s State Water Project. The U.S. Geological Survey (USGS) works cooperatively with the Bureau of Reclamati

Authors

Larry R. Brown, David E. Ayers, Brian A. Bergamaschi, Jon R. Burau, Evan T. Dailey, Bryan D. Downing, Maureen A. Downing-Kunz, Frederick V. Feyrer, Brock M. Huntsman, Tamara E. C. Kraus, Tara Morgan, Jessica R. Lacy, Francis Parchaso, Catherine A. Ruhl, Elizabeth B. Stumpner, Paul Stumpner, Janet Thompson, Matthew J. Young

Water Resources Mission Area, California Water Science Center, Pacific Coastal and Marine Science Center

January 29, 2016

Innovation in monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, flow-station network

The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station ne

Authors

Jon Burau, Cathy Ruhl, Paul A. Work

Water Resources Mission Area, California Water Science Center

March 24, 2008

Water quality

Sustainable water policy in California will require maintaining or improving water quality. The Delta is an important source of drinking water for Californians, but sustaining a quality sufficient for human and agricultural consumption presents a number of problems and challenges to water managers. Similarly, poor environmental water quality is recognized as one of the influential stressors contri

Authors

Samuel N. Luoma, Susan Anderson, Brian A. Bergamaschi, Lisa Holm, Cathy Ruhl, David H. Schoellhamer, Robin Stewart

Water Resources Mission Area, California Water Science Center

February 25, 2005

Computation of discharge using the index-velocity method in tidally affected areas

Computation of a discharge time-series in a tidally affected area is a two-step process. First, the cross-sectional area is computed on the basis of measured water levels and the mean cross-sectional velocity is computed on the basis of the measured index velocity. Then discharge is calculated as the product of the area and mean velocity. Daily mean discharge is computed as the daily average of th

Authors

Catherine A. Ruhl, Michael R. Simpson

September 1, 2004

Investigation of hydroacoustic flow-monitoring alternatives at the Sacramento River at Freeport, California: results of the 2002-2004 pilot study

The Sacramento River at Freeport is a tidally affected channel approximately 620 feet wide located at the northern boundary of the Sacramento?San Joaquin River Delta, California. In 1978, an acoustic velocity meter was installed at Freeport to monitor the flow. The acoustic velocity meter was calibrated successfully and has been used continuously since that time. Although the calibration has been

Authors

Catherine A. Ruhl, James B. DeRose

January 1, 2004

Spatial and temporal variability of suspended-sediment concentrations in a shallow estuarine environment

Shallow subembayments respond differently than deep channels to physical forces acting in estuaries. The U.S. Geological Survey measured suspended-sediment concentrations at five locations in Honker Bay, a shallow subembayment of San Francisco Bay, and the adjacent channel to investigate the spatial and temporal differences between deep and shallow estuarine environments. During the first fres

Authors

Catherine A. Ruhl, David H. Schoellhamer

Water Resources Mission Area, California Water Science Center

December 1, 2001

Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 1999

Suspended-sediment concentration data were collected in San Francisco Bay during water year 1999 (October 1, 1998-September 30, 1999). Optical backscatterance sensors and water samples were used to monitor suspended sediment at one site in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two dep

Authors

Paul A. Buchanan, Catherine A. Ruhl

January 1, 2001

Time series of suspended-solids concentration, salinity, temperature, and total mercury concentration in San Francisco Bay during water year 1998

Many physical processes affect how constituents within San Francisco Bay vary. Processes and their associated time scales include turbulence (seconds), semidiurnal and diurnal tides (hours), the spring-neap tidal cycle (days), freshwater flow (weeks), seasonal winds (months), ecological and climatic changes (years), and geologic changes (thousands of years). Continuous time series of data on basic

Authors

Catherine A. Ruhl, David H. Schoellhamer

January 1, 2000

Exposure of delta smelt to dissolved pesticides in 1998 and 1999

Delta smelt is a threatened species in the San Francisco Bay Estuary. Pesticide toxicity is a possible cause for the need to list this fish (Bennett and Moyle 1996; Moyle and others 1996). Numerous pesticides are transported into the estuary from area rivers (MacCoy and others 1995). However, there are minimal data to document the presence, or absence, of pesticides within delta smelt habitat, esp

Authors

G. Edward Moon, Kathryn Kuivila, Catherine A. Ruhl, David H. Schoellhamer

Water Resources Mission Area, California Water Science Center

January 1, 2000

Summary of suspended-solids concentration data, San Francisco Bay, California, water year 1998

Suspended-solids concentration data were collected in San Francisco Bay during water year 1998 (October 1, 1997?September 30, 1998). Optical backscatterance sensors and water samples were used to monitor suspended solids at two sites in Suisun Bay, three sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water sample

Authors

Paul A. Buchanan, Catherine A. Ruhl

January 1, 1999

Time series of suspended-solids concentration in Honker Bay during water year 1997

Suspended-solids concentration (SSC) responds differently to seasonal variations, such as Delta outflow and wind in shallow water areas than in deep-water channels. Although San Francisco Bay includes extensive areas of shallow water, with about one-half of the surface area of the Bay being less than 2 meters deep (Conomos and Peterson, 1977), deep-water channels along the spine of San Francisco B

Authors

Catherine A. Ruhl, David H. Schoellhamer

Label

link

Side-looking acoustic Doppler velocity meter and water quality sonde

March 4, 2021

Flow and Water Quality Data in the San Francisco Estuary

The San Francisco Bay and Sacramento-San Joaquin Delta form one of the largest estuaries in the United States. Water flow and water quality in the San Francisco Bay-Delta Estuary are important to the economies of both California and the nation. The Bay-Delta system provides water to more than 25 million California residents and vast farmlands, as well as key habitat for birds, fish, and other...

California Water Science Center

link

March 4, 2021