Starting on or around the second week of April 2026, residents across 15 to 16 counties in southwest Michigan will notice an unusual sight in the sky. The Michigan Department of Environment, Great Lakes, and Energy (EGLE), in partnership with the United States Geological Survey (USGS) Upper Midwest Water Science Center, will be conducting airborne electromagnetic (AEM) surveys to study our local groundwater resources. These flights are scheduled to continue for three to four months.
If you look up and wonder what is going on, here is a complete breakdown of what you are seeing, why it is happening, and where you can find more information.
What Will You See?
You will see a helicopter flying at approximately 50 mph, roughly 200 feet above the ground. Suspended about 100 feet below the helicopter will be a massive sensor hoop that is over 60 feet in diameter and weighs over 2,000 pounds.
Because the helicopter is required to fly a pre-determined, gridded flight track based on specific study locations to collect accurate data, you will likely see it pass over the same area several times.
Why Are They Mapping the Ground?
This initiative is part of the larger Hydrologic Enhancement for Michigan (HEMI) project, a collaboration between EGLE and USGS designed to expand surface water and groundwater data collection across the state.
The AEM survey acts somewhat like an MRI for the earth. As the helicopter flies, the sensors in the hoop measure how well the ground conducts electricity. This allows scientists to map the 3D distribution of underground sediment, rocks, and aquifers, which is a fast and highly effective way to understand our underground geology.
Mapping this unseen resource is incredibly important because 44% of Michigan residents get their drinking water from groundwater. Furthermore, groundwater naturally supplies water to our rivers, lakes, and streams, and is used heavily for irrigation and industry. By better understanding where water is stored, state managers can make informed decisions to protect our water supply.
Is it Safe?
Yes. EGLE and the USGS have highlighted several important safety facts regarding the AEM survey:
- No Harm to Life: The electromagnetic device being used will not harm plants, animals, or humans. The magnetic field generated is exceptionally low, measuring less than 1/100th of the accepted general public exposure level. It is roughly the equivalent of standing one foot away from a kitchen toaster.
- Flight Restrictions: According to Federal Aviation Administration (FAA) rules, the helicopter will not fly within 500 feet of buildings.
- Avoidance Measures: The pilots will make conscious efforts to fly around people, livestock, and large equipment on the ground.
Track the Flight and Learn More
If you are curious to track the helicopter’s progress or learn more about the project, please use the buttons provided below. You can access the Southwest MI AEM Survey webpage, which includes a map of the survey area and access to the USGS Flight Tracker. The tracker will be updated live once the flights officially begin.
For those who want a deeper dive into the science and planning, you can also use the buttons below to view a recording of the January 2026 Local Officials webinar regarding the survey along with a copy of the presentation slides, which are available to the public on EGLE’s HEMI project website.
