River Stage Sensors

Project Personnel (University of Iowa): Dr. Anton Kruger (Associate Professor),  Jim Niemeier (PhD Student), Matt Kemp (Student), Ben Peiffer (Student) and Nick Sitter (Student)

One of the lessons learned from the devastating 2008 floods was that current gauging stations do not provide sufficient data for real-time flood forecasting.  Due to the expenses associated with current gauges (costly infrastructure, equipment, and maintenance), it is not feasible to place them at a large number of small, medium, and large streams.  The purpose of this project is to develop an affordable monitoring system that can be installed across the state to supplement data from other sources and to obtain up-to-the-minute data on Iowa’s numerous streams.

Electronics inside the sensor.

Our team is developing an electronic automated sensor that measures stream water height (stage) and transmits this measurement automatically and frequently to a central location.  The sensor is placed under bridges and uses a sonar signal to measure the distance from the water surface to the sensor. Data from the sensor, and other known parameters at each site, are used to determine stream flow and thus flood stage.

Our sensor prototype was deployed on a local bridge in late 2009.  We are currently testing it and making corrections to account for different variables such as changes in ambient temperature. (Since the speed of sound varies with temperature, we noticed fluctuations in sensor data depending on the air temperature.)

There are over 2,000 bridges in Iowa that might be used in this new system.  Thus, a key element of this project is affordability.  The current sensor system target cost is about $1,000 per unit, which is a fraction of the cost of other current gauging systems.  We are trying to further reduce this cost to maximize the number of new sensors we can deploy.

Nick Sitter deploying the first sensor

The most important benefit of having real time stream stage data on Iowa’s many streams is an increase in public safety.  This system will make it possible to be more precise in determining areas currently affected by flooding, the magnitude of current flooding, and the contribution of different streams to flooding on a larger river.  It will also be possible to use the sensors to provide immediate notice to emergency officials when a bridge is impassable due to flooding.

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

Additional Information:
Matt Kemp and Ben Peiffer recently won a Pappajohn Elevator Competition with this project.