USGS hydrologic technician James Foreman operates an electronic deployment reel from a bridge over the Elwha River, Washington. Two large dams on the Elwha River are being incrementally removed from 2011 to 2013 to restore river function in an important salmon-bearing river.
Water quality sampling from a bridge
By Washington Water Science Center
March 1958 (approx.)
Detailed Description
Hydrologic Technicians use bridge cranes and reels to collect water quality samples. Similar technology is still in use today.
Sources/Usage
Public Domain.