Bay-Delta
Bay-Delta
The Sacramento-San Joaquin River Delta and San Francisco Bay collectively make up the "Bay-Delta." Much of the fresh water used for agriculture, municipal and industrial use in central and southern California passes through the Delta, where it is subjected to tidal forcing and other inputs that impact its quality. The USGS monitors the magnitude of the flows through the Delta, and the qua
USGS Science at Work in the San Francisco Bay Estuary
USGS Science at Work in the San Francisco Bay Estuary
In an article written for the Interagency Ecological Program for the San Francisco Estuary, Dr. Paul Work and Dr. Maureen Downing-Kunz, of the California Water Science Center, provide examples of the work being done to measure water flow and quality.
Topics Related to the Bay-Delta
Topics Related to the Bay-Delta
See some of the other ways USGS science is at work in the San Francisco Bay and Sacramento-San Joaquin Delta.
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Pesticide Fate Research Group (PFRG)
Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Low Intensity Chemical Dosing (LICD)
Rivers, wetlands, and agricultural operations supply natural organic material to the Sacramento-San Joaquin Delta (Delta) and the San Francisco Estuary. This natural organic matter provides many ecosystem benefits, but it also adversely affects drinking water. During drinking water treatment, chlorine added for purposes of pathogen control reacts with dissolved organic carbon (DOC) in the water to...
Water Quality after a Wildfire
About half of the water supply in the southwestern United States is supplied by water from forests, which generally yield higher quality water than any other source. Approximately 80 percent of the freshwater resources in the U.S. originate on forested land, and more than 3,400 public drinking-water systems are located in watersheds containing national forest lands (USDA, 2006). More than 12...
Assessing Deposit Build-up in Corte Madera Flood Control Channel
The Corte Madera Flood Control Channel was designed to prevent waters from overflowing Corte Madera Creek in a highly populated area of Marin County. Since the channel was last dredged in 1990 approximately 5,400 cubic feet of sediment has accumulated. The accumulation of sediment is of concern because the sediment may reduce the effectiveness of the channel, posing a flooding threat to...
Effects of Aquatic Vegetation on Water Quality and Residence Time in the Bay-Delta
The spread of invasive aquatic vegetation in the Sacramento-San Joaquin Delta is having a profound impact on the Delta’s natural habitat. The presence of these “aquatic weeds” has been shown to alter water velocity and increase water clarity, posing threats to native fish species, specifically the threatened Delta Smelt. These aquatic plants can also affect the foodweb by altering nutrient...
Improved Monitoring of Water Quality and Pelagic Organism Decline in the Delta with Continuous In Situ Sensor Measurements
Newly-developed, commercially-available sensors permit real-time collection of water quality data that may help identify ecosystem processes that affect the health of pelagic food webs in the Sacramento – San Joaquin Delta. In particular, the simultaneous measurement of nutrients, organic matter and algal abundance along with the basic water quality variables such as temperature and salinity -...
Application of the SmeltCam to Describe Processes Influencing Delta Smelt Distribution and Movements
The California Water Science Center's "SmeltCam" helps describe processes influencing Delta Smelt distribution and movement.
Understanding Influences on Habitat Quality for Delta Smelt and Other Imperiled Fish Populations
USGS scientists work to provide information needed to evaluate the efficacy of ongoing U.S. Burueau of Reclamation water management efforts in Bay-Delta.
Technical Support and Synthesis of Data Collected on the Health and Status of Delta Smelt
USGS scientists work to provide data to UC Davis researchers on health and growth of smelt population in Bay-Delta.
Rearing Habitats of Longfin Smelt in the Low Salinity Zone of the San Francisco Estuary
Scientists study habitats occupied by longfin smelt larvae to better understand their ecology and to inform water management operations, species management, and habitat restoration efforts.
Physical and Biological Drivers of Longfin Smelt Vertical Distribution
Research scientists study conditions that affect abundance and distributions Longfin Smelt fish population.
Abiotic and Biotic Effects on Delta Smelt Abundance and Distribution
Scientists research the importance of abiotic versus biotic (food supply) habitat features as drivers of delta smelt abundance and distribution.