| California Dept of Water Resources CDEC | California Data Exchange Center: river conditions, snowpack, precipitation, query tools. Also see 'other sources' link at http://cdec.water.ca.gov/sources.html |
| Streamflow and some water quality parameters. Other links find groundwater and other data. Daily, Monthly and Annual data. | |
| USGS Water-Quality Data for California | very limited water quality data -- mostly discharge |
GIS data sources
| Seamless.usgs.gov | USGS Seamless: for elevation, imagery, and other GIS data layers |
| National Hydrography Dataset | National Hydrography Dataset: surface water features such as lakes, ponds, streams, rivers, springs and wells |
| USGS National Geologic Map Database | |
| USGS San Francisco Bay Water Quality Data |