You hear us talk about this work year after year—but do you know what the data is used for?
Not only does the streamgage network support all the functional areas of MCD (flood protection, water stewardship, and recreation), but it also supports the work for a lot of other agencies and communities outside of MCD that is critical for regional, state, or even national planning and decision-making.
Our team works hard to make sure this critical network is running 24/7. That means regular calibration of equipment, measuring streamflow under all river conditions, and maintaining gage ratings (the relationship between water height and streamflow). We also use physical tools like staff boards (vertical measuring sticks) and wire-weight devices (plumb lines that measure water surface elevation) to verify electronic readings and ensure accuracy.
In particular, the streamgage network maintained by our hydro teams and USGS contributes to all of the following:
1. MCD High-Water Operations
Our staff monitor water levels in real time to decide when to take protective actions, such as closing floodgates, inspecting levees and dams, reading monitoring wells, or activating the Emergency Action Plans when conditions warrant.
2. Dam Safety and Infrastructure
Streamgage data helps identify concerns like underseepage (water moving underneath a dam or levee) and streambank erosion. These insights are used to design and prioritize infrastructure upgrades that make our flood protection system more resilient during high-flow events.
3. Probable Maximum Flood (PMF) Analysis
The Probable Maximum Flood represents the worst-case scenario flood event. Engineers use streamgage data to build computer models that simulate PMF conditions and evaluate whether a dam’s emergency spillway (its overflow channel) can safely handle such an event.
4. U.S. Geological Survey – National Water Information System (NWIS)
All of our streamgage data is shared with the USGS and posted on NWIS, a public online tool that displays real-time and historical water data. It’s used by scientists, policy makers, educators, and residents to monitor streamflow, flooding, drought, and water supply.
5. Flood Forecasting – Ohio River Forecast Center (OHRFC)
The OHRFC uses streamgage data to predict how rivers will respond to forecasted rainfall. These forecasts are crucial to emergency responders and public officials preparing for possible flood events.
6. FEMA Floodplain Mapping
The Federal Emergency Management Agency (FEMA) uses long-term streamgage data to build models that define where floodwaters are likely to flow during large storms. These models inform floodplain maps, which help guide building codes, land use decisions, and flood insurance requirements.
7. Ohio EPA Water Quality Monitoring
When the Ohio Environmental Protection Agency assesses river health by studying fish and macroinvertebrates (tiny aquatic organisms like mayflies and snails), they document streamflow at the time of sampling. This context helps scientists interpret their findings more accurately.
8. Wastewater Discharge Permits (NPDES)
Streamflow data is used when setting limits for pollutants in National Pollutant Discharge Elimination System (NPDES) permits. These permits regulate what wastewater treatment plants can release into rivers, ensuring water quality is protected even during low-flow conditions. Those permits keep our water clean.
9. U.S. Drought Monitor
Streamgage readings contribute to drought assessments by showing how much water is (or isn’t) flowing through rivers and streams. The Drought Monitor uses this information to categorize drought severity across the country.
10. Academic and Consultant Research
Researchers and environmental consultants use our data for everything from climate change studies to infrastructure design. Here’s one recent example of how thw MCD/USGS streamgage data supported published scientific research.
11. Public Safety and Recreation
It’s not just scientists and engineers who benefit from this information. Paddlers, anglers, and outdoor enthusiasts across the Great Miami River Watershed check streamgage readings to decide when it’s safe to get on the water. This data used behind-the-scenes to ensure the Great Miami Riverway River Conditions Map is up to date.
Not Always Glamorous, But Always Important!
This work often means being outside in tough weather no matter the cold, rain, wind, and mud. But our team shows up, rain or shine, to keep this essential system operating.
So the next time you hear a flood forecast remember the Miami Conservancy District staff behind the scenes. We’re out there doing the dirty work that keeps our region safe, informed, and resilient.
