Editing Stream gauge (section)

===United States===
[[Image:USGS.12149000.01.00060..20070306.20070313.1.0.p50.pres.png|thumb|upright=1.35|[[Hydrograph]] of the March 13, 2007 [[Snoqualmie River]] flood]]

In the United States, the [[U.S. Geological Survey]] (USGS) is the principal federal agency tasked with maintaining records of stream flow data. Within the USGS, the Water Resources Division carries the responsibility for monitoring water resources.

To establish a stream gauge, USGS personnel first choose a site on a stream where the geometry is relatively stable and there is a suitable location to make discrete direct measurements of streamflow using specialized equipment.  Many times this will be at a bridge or other stream crossing.  Technicians then install equipment that measures the '''stage''' (the elevation of the water surface) or, more rarely, the '''[[velocity]]''' of the flow.  Additional equipment is installed to record and transmit these readings (via the [[Geostationary Operational Environmental Satellite]]) to the Water Science Center office where the records are kept.  The USGS has a Water Science Center office in every state within the United States.  Current streamflow data from USGS streamgages may be viewed in map form at: [http://waterwatch.usgs.gov/?id=ww_current].