Sangamon River At Petersburg flow report
As of July 13, 2026, Sangamon River At Petersburg is flowing at 3,540 cfs with a gage height of 9.40 ft, rising 26% over the past 24 hours. Source: USGS gauge #05578000, refreshed throughout the day.
Historical Data
Sangamon River At Petersburg at a glance
How Sangamon River At Petersburg is running right now, where it sits on the map, and the key gauge stats.
Sangamon River At Petersburg is flowing at 3,540 cfs, with the water sitting 9.40 ft at the gage. Flow is up 26% since yesterday — a rising hydrograph.
This is USGS gauge #05578000 in Illinois. Over the past 10 days the average has been 2,613 cfs, peaking at 3,540 cfs.
Over the next 5 days, Sangamon River At Petersburg is expected to recede from today's 2810 cfs, toward roughly 1820 cfs by 2026-07-17 (likely range 468-7083 cfs) -- drier than normal for the date.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Illinois flow report.
Streamflow Forecast
Powered by PULSE — Snoflo’s Predictive Unified Learning & Simulation Engine, which learns from how this river has answered every past storm, snowmelt, and dry spell to forecast where it’s headed with a precision generic models can’t match.
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Sangamon River At Petersburg
The river is fed by several small tributaries and is also influenced by the nearby Lake Petersburg dam. Seasonal trends show high flows in the spring due to snowmelt and rainfall, and lower flows in the summer and fall. The river is also known for its diverse aquatic life, including several species of fish and mussels. Interestingly, the name "Sangamon" is derived from a Native American word meaning "where there is plenty to eat."
Nearby streamflow levels
Cross-check Sangamon River At Petersburg's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Sangamon River At Petersburg | 2,810 cfs |
| Salt Creek Near Greenview | 1,470 cfs |
| Sangamon River Near Oakford | 3,930 cfs |
| Spring Creek At Springfield | 162 cfs |
| Sangamon River At Riverton | 3,020 cfs |
| South Fork Sangamon River Nr Rochester | 483 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Sangamon River At Petersburg. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Lincoln 4.6 W | 0 in |
| Buffalo | 0 in |
| Jacksonville | 0 in |
| Central Illinois | 0 in |
| Jacksonville 2 | 0 in |
| Edinburg 3.0 W | 0 in |
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Sangamon River At Petersburg in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Sangamon River At Petersburg crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Sangamon River At Petersburg
Where does the streamflow data for Sangamon River At Petersburg come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 05578000. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Sangamon River At Petersburg rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Sangamon River At Petersburg report
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