Underwater Stream Sensors

Project Personnel (University of Iowa): Dr. Anton Kruger (Associate Professor), Greg Wagner (Engineer II), and Dan Ceynar (Engineer II)

Underwater sensors deployed in an Iowa stream

This project is similar to the River Stage Sensors project as it involves developing a sensor that conveys information about stream stage for a variety of different sized streams.  It can also provide up-to-the-minute data on stream depth and it is relatively inexpensive so we can deploy many of them across the state.  However, this sensor does not require an overhead bridge. 

Our underwater stream sensors measure water depth by measuring the pressure at the bottom of the stream.  The sensor detects the pressure above it, which is a factor of the water depth and atmospheric pressure at the stream’s surface.  Water depth can be calculated from this measurement after subtracting the atmospheric pressure.  (Commercially available gauge pressure sensors automatically account for the atmospheric component, but require an expensive cable with a vent tube and regular on-site maintenance for reliable performance.)

Greg Wagner with the datalogger and solar panel for the sensor mounted in a tree by the stream.

The Iowa Flood Center is developing microprocessor-based stream gauges using absolute pressure sensors mounted on the stream bottom and connected via an inexpensive cable to a custom datalogger along the stream bank.  The low-power electronics associated with the datalogger include an atmospheric pressure sensor for reference, solar-rechargeable battery power, local data storage, real time clock, and telemetry capability.

Ongoing development of these stream gauges includes making the sensors remotely reprogrammable to facilitate real-time data collection, calibration, and firmware upgrades with minimal physical interaction.

Funding Source for this Project:
State of Iowa, Iowa Flood Center