About this river
Rock River is a 21.6 mile river near Quad Cities Kayak River Adventures in Illinois. Streamflow is measured at the USGS gauge Rock River near Joslin, IL (site 05446500). The National Hydrography Dataset places it at stream order 8. Reach geometry comes from the USGS National Hydrography Dataset.
Typical flow by month
1940 to 2026
Rock River typically runs highest in March, at a median 9,980 cfs, and lowest in September, at 3,745 cfs. The highest flow on record for any single day is 46,700 cfs, in 2013.
| Month | Typical (cfs) | Usual range (cfs) | Relative level |
|---|---|---|---|
| January | 4,700 | 3,200 to 7,200 | |
| February | 4,900 | 3,300 to 8,400 | |
| March | 9,980 | 6,760 to 14,900 | |
| April | 9,965 | 7,020 to 14,950 | |
| May | 8,270 | 5,600 to 11,600 | |
| June | 6,785 | 4,160 to 10,750 | |
| July | 4,730 | 3,140 to 9,110 | |
| August | 4,160 | 2,610 to 6,390 | |
| September | 3,745 | 2,385 to 5,770 | |
| October | 4,030 | 2,390 to 6,090 | |
| November | 4,885 | 2,940 to 6,960 | |
| December | 5,000 | 3,200 to 7,060 |
Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 87 years of record. Statistics published by the US Geological Survey for Rock River near Joslin, IL (site 05446500). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.
Boat access nearby
8 mapped launches sit in the mapped area of Rock River, all of them public access. Ramp data comes from the USGS national boat-ramp inventory.
- Rock River Lunch ParkRock RiverPublic
- Hennepin CanalHennepin CanalPublic
- Hennepin CanalHennepin CanalPublic
- Hennepin CanalHennepin CanalPublic
- Isaak Walton LeagueHennepin CanalPublic
- Sunset Park Boat RampMississippi RiverPublic
- Cleveland boat rampPublic
- Marquette StMississippi RiverPublic
Embed this gauge on your site
Paste this snippet anywhere, an outfitter page, a club site, a trip report, to show Rock River's live streamflow, water level and 7-day trend. It reads the USGS gauge directly, updates itself, and links back here.
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