A University of Iowa research engineer has invented a custom physics-based approach for measuring the flow in rivers and streams, which could benefit applications ranging from design of riverine structures to flood warnings and water resource management.

The vast majority—about 95%—of flood‑monitoring systems operated by the U.S. Geological Survey rely solely on river‑stage measurements to estimate discharge using rating curves. Developing and maintaining these rating curves is costly, labor‑intensive, and still not sufficiently accurate for real‑time applications. 

Monitoring agencies recognize the limitations of this approach, particularly during transitional flow conditions and extreme events, and often apply additional corrections that require significant time and resources. As a result, many stations remain uncorrected, reducing the reliability of the overall monitoring network.

The measurement system developed by Marian Muste, a research engineer at IIHR—Hydroscience and Engineering, continuously and simultaneously measures multiple flow variables, including stage, velocity, and free-surface slope. The major advantage of Muste’s version is accurate, real-time discharge measurements during normal, transition, and extreme flows without using rating curves.

Muste recently received a patent for his method. He plans to continue refining the process with the intent to eventually create a startup company for bringing the approach to market

Muste’s methodology has been supported through more than $1.5 million in funding through the National Science Foundation and the Cooperative Institute for Research to Operations in Hydrology (CIROH), a National Oceanic and Atmospheric Administration funded program. CIROH is a consortium of partners working together to advance water prediction for the nation and is based at the University of Alabama.