Images

Nearly completed construction of a streamgage structure in 1955 at Elm Fork Trinity River near Carollton, Texas.

This 1922 photo shows an early USGS streamgage on the Trinity River in Dallas.

Currently, most of the streamflow equipment is located on a streambank or bridge. Large structures are no longer needed at most streamgage locations. Today, streamgage equipment can be contained in small metal shelters that are located on streambanks or bridges.

This 2014 photo shows the new location of the USGS streamgage that measures high flows on the Trinity River in Dallas. The gage was once located on a pier, but in 1975 was moved next to the stream. 

Construction in 1939 of a streamgage structure at Elm Fork Trinity River near Carrollton, Texas.

One of the oldest versions of a streamgage structure constructed in Texas.

A close-up view of the top part of one of the oldest streamgage structures constructed in Texas.

In the earlier years of streamgaging, large “stilling wells” were constructed to contain the equipment needed to collect streamflow data. Historically, most of the streamflow equipment may have been located in these large structures, which were placed in the middle or next to the stream.

Instrumentation for measuring real-time groundwater properties at the SGW-93 bedrock-aquifer public-supply well pump house in Seabrook, NH. Read the journal article.

Walker Lake in Nevada on a Spring day

Coal tar is a byproduct of the coking, liquefaction, or gasification of coal. Coal-tar pitch is the residue that remains after the distillation of coal tar. Coal tar and coal-tar pitch are used in coal-tar-based sealcoat products, although use of coal-tar pitch is more common than use of coal tar. Both coal tar and coal-tar pitch are known human carcinogens.

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in settings near pavement sealed with coal-tar-based sealants were substantially higher than concentrations in settings where coal-tar sealant was not used.

Coal-tar-based sealcoat is a potent source of PAHs and related chemicals. Worn particles of coal-tar-based sealcoat are transported by rain, wind, tires, and even our feet from pavement to other environmental settings. Sealcoat product (A), after it dries, gradually abrades to a powder and becomes part of the dust on the pavement (B).

Cool, clear rivers of the Texas Hill Country attract visitors for many recreational opportunities. Here, a family enjoys paddleboarding at Schreiner Park during spring break in Kerrville, Texas.

Soper Branch stream with a USGS streamgage on the bridge. Soper Branch is a small stream near Hyattstown, MD, that is part of the Chesapeake Bay watershed.

H.D. McGlashan measures streamflow in the Merced River, circa 1920. Multiple velocity and water-depth measurements along a stream cross section are used to calculate the total volume of water passing a certain location over a specific period of time (cubic feet per second).

Location: Merced River, Yosemite National Park, California

A member of the USGS Glen Canyon Adaptive Management Working Group in Flagstaff, Ariz., monitors the Colorado River downstream of Glen Canyon Dam.

A photo taken before the Great Works Dam was removed (likely in 2009), looking upstream from a boat just upstream of the Great Works Dam.

This USGS file photo was taken at a USGS gaging station on the Passadumkeag River at Lowell, Maine (01035000) in 1915. The USGS collected streamflow at this location from 1915 through 1979. The photo shows an unknown hydrographer standing next to a chain gage. The chain gage was used by a local observer to make manual readings of water level. 

Young boys working in a newly cropped field in Africa.

The outlet tubes of Glen Canyon Dam were opened during the 2004 high-flow experiment on the Colorado River.