March 22, 2019

Swept Away: Stream Gauges Essential to Storm Resilience

Posted by bwebster

Today’s post is in Honor of World Water Day and is by Dr. Amy Marcarelli (@AmyMarcarelli). Dr. Marcarelli is an associate professor of biological science at Michigan Technological University. Her research links nutrient and carbon cycling with ecological community dynamics in river, stream and lake ecosystems.

One of the most basic characteristics used to describe a stream is its discharge—how much water it carries. Discharge tells us how quickly something that is added to the river will dilute and move downstream. A river’s discharge rate also tells us how prone the river is to disturbances and what conditions the organisms living there experience.

Understanding how river discharge changes through time is key for human communities. It allows planning for how quickly lakes and reservoirs fill and how much water can be withdrawn for irrigation or drinking. River discharge records are also crucial for estimating and predicting flood frequency—how often discharge events of a certain size occur. This helps communities understand when a river is likely to flood, and how to build culverts and bridges that are robust to the highest flows that are likely to occur on a regular basis. The more data we have, the better we get at predicting the likelihood of rare events—particularly those large natural disasters that wipe out culverts, roads, bridges and everything else in their paths.

This image compilation shows how the Pilgrim River rose and receded during the June 17 flood. The top left image shows the river June 16, the day before the flood. The top right image shows the Pilgrim River June 17, the day of the flood. The two bottom images show the river on June 18 and 19. The images were captured by a trail camera installed at the Tech Trails overlooking the Pilgrim River. Image Credit: Kevin Nevorski

For all of these reasons, the U.S. Geological Survey (USGS) and partners operate a nationwide streamflow monitoring program. The data from these rivers is used to both understand current streamflow conditions, as well as to create long-term records of river discharge.


“The national stream gauge network is used for many different purposes,” said Don Cline, Associate Director for Water Resources for the USGS, in an interview with Michigan Tech staff in November 2018. “These include protecting lives and property and flood forecasting. The National Weather Service has a mission to provide flood watches and warnings, and they can’t do that without the stream gauges.”

Sparse Stream Gauge Data Amplifies Impacts of Flooding

In October this vital network experienced a software failure that caused 1,200 of the 8,300 gauges to fail. Those gauges have since been repaired, but the temporary outage caused a scramble for weather forecasters, emergency managers, and communities around the country.

Houghton, located in the Keweenaw Peninsula on the Upper Peninsula of Michigan, experienced a catastrophic 1,000-year flood in June 2018. Historically, there have been very few USGS discharge monitoring stations in the Keweenaw. The gauge at the Trap Rock River near Lake Linden, which is funded cooperatively by the USGS and Michigan Department of Environmental Quality, has continuously monitored discharge since 1966, which seems like a long time, but 50 years of data is still not enough to accurately predict rare events.

To increase the understanding of spatial variation in water flow in the Keweenaw, the USGS installed four temporary gauges with Great Lakes Restoration Initiative funds in 2014 at the Pilgrim River, Coles Creek, Gratiot River and the Montreal River.

When initial funding ran out, the gauges at Coles Creek and the Montreal were shut down, but researchers at Michigan Tech and the U.S. Fish and Wildlife Service lobbied the USGS to keep the gauges at the Gratiot and the Pilgrim rivers going through September 2018. At Michigan Tech, we particularly rely on the gauge at the Pilgrim to provide data used in support of graduate student research on nutrient cycling and fish movement, as well as for teaching in general and aquatic ecology classes.

The bridge at Paradise Road over the Pilgrim River washed out during the June 17, 2018 flood. Several USGS stream gauges were swept away in the flooding. Image Credit: James R. Melchiori

All was going well, until the June flood took out the culvert and bridge at Paradise Road, also wiping out the USGS gauge. What will happen at this site now is unclear. The USGS is willing to reinstall the gauge at Pilgrim River if additional funding can be found to support its maintenance: $15,700 per year.

Collaborative Efforts to Bolster Water Monitoring

The Keweenaw is not the only area in the U.S. that suffers from a lack of river flow data—there are 30 million stream reaches in the U.S. the USGS has mapped, which puts in stark relief how inadequate a network of just 8,300 gauges is.

“From a sampling perspective, in the U.S. we don’t really measure our water,” Cline says. “That needs to change as we face ever more challenging water issues across different parts of the country, whether it’s too much or too little or poor quality.”

Cline says the USGS and its partners are considering what a next generation water observing system looks like. An increased number of stream gauges should be part of that model, but there are other methods used to monitor quality and quantity including innovating new sensors, citizen science, DIY gauges, and photographic histories of rivers. A centralized national repository of information would make sure data is easily accessible to researchers and policy makers alike.

These efforts are likely to be distributed among many different agencies and researchers. For example, Michigan Tech is one of five universities working together on a $1.5 million Smart and Connected Communities grant. The focus of the project—driven by a team of engineers, hydrologists and computer scientists—is to develop an integrated network that gathers, analyzes and alerts urban communities in danger of flooding.

Unfortunately, Cline is correct when he notes that “People don’t think about a flood much until it happens and then they wish they had the information. That’s where we’re at with stream gauges. We’re trying to think holistically for the whole country to see if we can elevate the network to meet next generation challenges.”


Michigan Tech celebrates World Water Day March 21-26 with events related to the United Nations theme, “Leaving No One Behind – Human Rights: Near & Far.” Monica Lewis-Patrick (aka The Water Warrior), the co-founder, president & CEO of We the People of Detroit, will be the keynote speaker on Monday, March 25.