How high is the Fox River (tailwater) at Algonquin, IL right now?

The Fox River (tailwater) at Algonquin, IL is currently flowing at 634 cubic feet per second with a gage height of 5.22 feet, based on the most recent USGS instantaneous reading.

Is the flow on the Fox River (tailwater) at Algonquin, IL normal for this time of year?

Current flow is classified as normal for June 11. Today's discharge is at the 26th percentile compared to the long-term historical record at this gauge.

Is the Fox River (tailwater) at Algonquin, IL at flood stage?

No — the gage height is 4.28 feet below the NWS flood-stage threshold of 9.5 feet.

What is the historical median flow for the Fox River (tailwater) at Algonquin, IL on June 11?

The long-term median discharge for this date is 979 cfs based on USGS daily statistics. The 10th–95th percentile range historically is 321 to unavailable cfs.

Where is the Fox River (tailwater) at Algonquin, IL stream gauge located?

The Fox River (tailwater) at Algonquin, IL stream gauge is operated by the USGS in McHenry County, IL on the Fox River (tailwater). USGS site number 05550001 (coordinates 42.1619, -88.2939).

Fox River (tailwater) at Algonquin, IL

USGS Site No: 05550001 • Fox River (tailwater) • McHenry County, IL

Fox River (tailwater) at Algonquin, IL on the Fox River (tailwater) is currently at 634 cfs (Normal — 26th percentile for this date) . Gage height: 5.22 ft.

Reading from 1 week ago

634

CFS Discharge

5.22

Gage Height (ft)

Normal

Flow Condition

Normal

Flood Status

Historical Percentile Comparison

Today's discharge compared to the long-term record for June 11 at this station. Percentile rank shows what fraction of historical years had lower flow on this date.

Percentile	Label	CFS Threshold	Today's Flow
10th	Very Low threshold	321
25th	Low threshold	618
50th (Median)	Normal (median)	979	Today: 634 cfs
75th	High threshold	1,570
95th	Very High threshold	0

30-Day Hydrograph

Recent discharge plotted against the historical 10th–95th percentile envelope for the same calendar days. Source: USGS daily values + long-term statistics.

10th–95th historical Day-of-year median Recent discharge

30-Day Flow History

Date	Discharge (CFS)	Gage Ht (ft)
May 28, 2026	732	5.42
May 27, 2026	766	5.49
May 26, 2026	859	5.67
May 25, 2026	907	5.76
May 24, 2026	844	5.64
May 23, 2026	783	5.53
May 22, 2026	854	5.66
May 21, 2026	968	5.87
May 20, 2026	1,000	5.94
May 19, 2026	821	5.60
May 18, 2026	773	5.51
May 17, 2026	813	5.59
May 16, 2026	791	5.54
May 15, 2026	805	5.57
Apr 20, 2026	6,010	11.73
Apr 19, 2026	5,730	11.46
Apr 18, 2026	5,480	11.22
Apr 17, 2026	4,890	10.61
Apr 16, 2026	4,690	10.41
Apr 15, 2026	4,340	10.04
Apr 14, 2026	3,880	9.53
Apr 13, 2026	3,890	9.55
Apr 12, 2026	3,990	9.65
Apr 11, 2026	4,200	9.89
Apr 10, 2026	4,280	9.98
Apr 9, 2026	4,110	9.79
Apr 8, 2026	4,010	9.68
Apr 7, 2026	3,940	9.60
Apr 6, 2026	3,720	9.36
Apr 5, 2026	3,490	9.09

Station Information

USGS Site No: 05550001
State: IL
County: McHenry County
Coordinates: 42.1619, -88.2939
Drainage Area: 1,429 mi²
Datum (ft): 719.2
HUC Code: 07120006

View on USGS NWIS →

Flood Stage Thresholds

Action Stage: 9.0 ft
Flood Stage: 9.5 ft
Moderate Flood: 10.5 ft
Major Flood: 12.0 ft

Currently 4.28 ft below flood stage.

Recent Extremes

Max discharge: 6,010 cfs

Apr 20, 2026
Min discharge: 293 cfs

Aug 9, 2025
Days at flood stage: 14

Computed from the local daily-values archive.

Nearby Gauges

Salt Creek at Rolling Meadows, IL
15.8 mi · 8 cfs

Normal
Buffalo Creek Near Wheeling, IL
17.2 mi · 8 cfs

Normal
Kishwaukee River at Marengo, IL
17.6 mi · 64 cfs

Normal
Salt Creek at Elk Grove Village, IL
18.2 mi · 43 cfs

Normal
Des Plaines River at Lincolnshire, IL
19.4 mi · 121 cfs

Low