USGS Current Meter at the Bonnet Carré Spillway

Detailed Description
A current meter. The rotating silver cups measure how fast the water is flowing. Meanwhile, the black torpedo-shaped object is a weight that keeps the current meter relatively stationary and the fins keep the current meter facing into the approaching flow. Learn more about how USGS measures streamflow here:http://water.usgs.gov/edu/streamflow2.html
In late 2015/early 2016 unusually large rainfall in the Upper Mississippi River Valley led to significant flooding in Arkansas, Illinois, Louisiana, Mississippi, Missouri, and Tennessee. USGS crews responded to the flooding by collecting streamflow and water quality information and providing it to emergency responders.
Sources/Usage
Public Domain.