Fish Passage Forum
The locations of current and historical U.S. Geological Survey streamgages have been snapped to the medium resolution National Hydrography Dataset (NHD). The NHD contains geospatial information about mapped surface-water features, such as streams, lakes, and reservoirs, etc., creating a hydrologic network that can be used to determine what is upstream or downstream from a point of interest on the NHD network. An automated snapping process made the initial determination of the NHD location of each streamgage. These initial NHD locations were comprehensively reviewed by local USGS personnel to ensure that streamgages were snapped to the correct NHD reaches. About 75 percent of the streamgages snapped to the appropriate NHD reach location initially and 25 percent required adjustment and relocation. This process resulted in approximately 23,000 gages being successfully snapped to the NHD. This data set contains the latitude and longitude coordinates of the point on the NHD to which the streamgage is snapped and the location of the gage house for each streamgage. A process known as indexing may be used to create reference points (event tables) to the NHD reaches, expressed as a reach code and measure (distance along the reach). Indexing is dependent on the version of NHD to which the indexing is referenced. These data are well suited for use in indexing because nearly all the streamgage NHD locations have been reviewed and adjusted if necessary, to ensure they will index to the appropriate NHD reach.
Flow characteristics were computed from the daily streamflow data recorded at each streamgage for the period of record. The flow characteristics associated with each streamgage include:
First date (year, month, day) of streamflow data
Last date (year, month, day) of streamflow data
Number of days of streamflow data
Number of days of non-zero streamflow data
Minimum and maximum daily flow for the period of record (cubic feet per second)
Percentiles (1, 5, 10, 20, 25, 50, 75, 80, 90, 95, 99) of daily flow for the period of record (cubic feet per second)
Average and standard deviation of daily flow for the period of record (cubic feet per second)
Mean annual base-flow index (BFI) computed for the period of record (fraction, ranging from 0 to 1)
Year-to-year standard deviation of the annual base-flow index computed for the period of record (fraction)
Number of years of data used to compute the base-flow index (years)
Yes - Layer name:
USGS Gaging Stations
When using the map viewer, you will be prompted to either login with your state username and password, or use the public BIOS viewer. All CalFish layers are public layers and do not require a special log-in or state credentials.
CalFish Tabular Data
No - USGS stream gage data is not available through the CalFish database query.
Tabular data for a location of interest must be accessed through the USGS website. A USGS page with data specific to a station of interest can be accessed through the CalFish map viewer using the link field in the station's attributes. Or visit USGS Current Water Data for California to choose between a variety of options for querying this tabular data.
CalFish Data Downloads
No - The USGS gaging stations point feature class is not available as a CalFish download, but a nation wide version of the data set can be downloaded from this USGS site.
United States Geological Survey
Data Set Credit
This data set was clipped from the original USGS nationwide data set by the California Department of Fish and Game.
Point of Contact
US Geological Survey
437 USGS National Center
Reston, VA 22092