On this map, Schussler has circled the locations of stream gauges, many of them adjacent to bridges. “Co. Bridge” can be found adjacent to many of the encircled locations on the map. The map is bounded on the upper left by San Ramon, the lower left by “Ex Mission San Jose,” the upper right by the San Joaquin Valley, and the lower right by Cedar Mountain Ridge.
It is a bit challenging to imagine the Livermore Valley this ripe with streams today. But the Historical Archive has a number of photos of streams, including flooded streams and plains in the region.
According to the United States Geological Survey (USGS) webpage, “a streamgage’s primary purpose is to collect data on water levels and streamflow (the amount of water flowing through a river or stream over time]. Streamgages estimate streamflow based on (1) continuous measurements of stage height (the height of the water surface) and (2) periodic measurements of streamflow, or discharge, in the channel and floodplains.”
Again, the USGS notes, “Data from streamgages informs real-time decision-making and long-term planning on issues such as hazard preparations and response, infrastructure design, water use allocations, ecosystem management, and recreation. Direct users of streamgage data include a variety of agencies from all levels of government, utility companies, consulting firms, scientific institutions, and recreationists.”
More information can be found here: https://www.everycrsreport.com/reports/R45695.html.
Congress has provided the USGS with the authority and appropriations to conduct surveys of streamflow since establishing the first hydrological survey in 1889.
Today the general public can send an e-mail or text to receive instant information about a specific streamgage via USGS “WaterNow” service (accessible at http://water.usgs.gov/waternow).
Alternatively, persons can enroll to receive alerts about stream conditions with USGS “WaterAlert” (accessible at https://maps.waterdata.usgs.gov/wateralert ).
Users may identify and select USGS monitoring sites across the U.S. via USGS “National Water Information System: Mapper” at https://maps.waterdata.usgs.gov