Mackinaw River Flow
As of 2026-08-02, the Mackinaw River is flowing at a combined 587 cfs across 2 USGS streamgauges — 120% of normal for this time of year, versus a seasonal average of 488 cfs.
Total streamflow across the Mackinaw River was last observed at 587 cfs, and is expected to yield approximately 1,164 acre-ft of water today; about 120% of normal. River levels are high. Average streamflow for this time of year is 488 cfs, with recent peaks last observed on 2019-05-04 when daily discharge volume was observed at 26,190 cfs.
Maximum discharge along the river is currently at the Mackinaw River Near Green Valley reporting a streamflow rate of 363 cfs. This is also the highest stage along the Mackinaw River, with a gauge stage of 14.02 ft at this location. This river is monitored from 2 different streamgauging stations along the Mackinaw River, the highest being situated at an altitude of 611 ft, the Mackinaw River Near Congerville.
River streamflow levels
Daily aggregate streamflow across every monitored gauge along the Mackinaw River. Use the range buttons to zoom in on a specific period.
Total streamflow
Sum of all monitored streamgauges · daily
Every streamgauge along the Mackinaw River
All 2 USGS gauges Snoflo tracks for this river, with current flow, stage, recent change, percent of normal, and the gauge's all-time min / max. Click any header to sort. Cells are heatmapped relative to the column min/max -- darker blue = higher.
| Streamgauge▾ | Streamflow (cfs)▾ | Gauge stage (ft)▾ | 24h Δ (%)▾ | % Normal▾ | Min (cfs)▾ | Max (cfs)▾ | Elevation (ft)▾ |
|---|---|---|---|---|---|---|---|
|
Mackinaw River Near Congerville
IL
USGS 05567500
|
224 | 1.60 | 29.5 | 161% | 0 | 23,700 | 611 |
|
Mackinaw River Near Green Valley
IL
USGS 05568000
|
363 | 14.02 | 18.6 | 131% | 11 | 18,800 | 501 |
Maximum streamflow discharge by year
The single highest aggregate discharge recorded each year. Spotting the multi-year trend reveals droughts vs. wet cycles long before the headline daily flow does.
Annual peak discharge
From the river's full record · one point per water year
Streamflow elevation profile
Each bubble is one gauge along the river, plotted by current streamflow (x-axis) vs elevation (y-axis), sized by gauge stage. Reading top-to-bottom traces the river from headwaters down to its mouth -- you can see flow accumulate as elevation drops.
Elevation vs streamflow
One point per monitored gauge · bubble size = gauge stage
Mackinaw River
The Mackinaw River flows through central Illinois, spanning 130 miles from its headwaters in McLean County to its confluence with the Illinois River in Tazewell County. The river's name comes from the Native American word "Makinauk," meaning turtle. The Mackinaw River has a drainage area of 1,800 square miles and is fed by several tributaries. The river has two major reservoirs, including the Evergreen Lake and Lake Bloomington, which serve as sources of drinking water for nearby communities. The river is also used for recreational activities such as fishing, canoeing, and camping. It is a popular spot for fly fishing and is home to several species of fish, including smallmouth bass and channel catfish. The river also supports agricultural activities, including crop irrigation and livestock watering.
Track the Mackinaw River in the Snoflo app
Set per-gauge push alerts (e.g. "alert me when flow at the Russian R Nr Healdsburg crosses 5,000 cfs"), and Snoflo's iOS app pushes the moment USGS reports the crossing.
About the Mackinaw River
How is the Mackinaw River flowing right now?
As of 2026-08-02, the Mackinaw River is flowing at a combined 587 cfs across its USGS streamgauges, about 120% of normal for this date. The live per-gauge breakdown and 24-hour trend are shown above.
Is the Mackinaw River running high or low right now?
Check the percent-of-normal figure on this page: above 100% means the river is running higher than its seasonal average for the date, below 100% means lower. The per-gauge table shows which reaches are highest and lowest.
Where does the data for the Mackinaw River come from?
Streamflow and gauge stage data are sourced from the U.S. Geological Survey (USGS) National Water Information System. The aggregate flow shown at the top of the page is computed by Snoflo as the sum of all monitored gauges along the river.
How is "percent of normal" calculated?
Today's aggregate streamflow is compared to the historical average aggregate streamflow on this calendar day across the river's full record. 100% means right on average; values above 100% indicate above-normal flow (wet year); values below indicate below-normal (dry year or drought).
Why are some gauges showing very different flows?
Gauges along a river measure flow at different points: headwater gauges read what's coming off the snowpack or mountain runoff; downstream gauges integrate everything upstream, including tributary inputs. Wide spreads usually mean a tributary is contributing significantly between gauges.
What's the elevation profile chart showing?
Each bubble is one gauge along the river, plotted by streamflow (x-axis) and elevation (y-axis), sized by gauge stage. Reading top-down traces the river from headwaters to mouth -- you can see flow build as elevation drops.
Can I get alerts when a specific gauge crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app on a per-gauge basis. Open any individual streamgauge from the table above and favorite it to set a discharge threshold.