« Back to Jefferson County Rivers
Rock River at Lake Koshkonong
Critical Stages
9' - Action
10' - Flood
11' - Moderate
11.5' - Major
Latest Observation
Updated: 4:00 AM CST 12/8/25
Status: No Flooding
Stage: 6.09 ft
Flow: -999 kcfs
Forecast
Forecast not available for this location.
| Time | Stage (ft) | Flow (kcfs) |
|---|---|---|
| 4:00 AM 12/8 | 6.09 | -999 |
| 3:45 AM 12/8 | 6.1 | -999 |
| 3:30 AM 12/8 | 6.09 | -999 |
| 3:15 AM 12/8 | 6.1 | -999 |
| 3:00 AM 12/8 | 6.09 | -999 |
| 2:45 AM 12/8 | 6.1 | -999 |
| 2:30 AM 12/8 | 6.09 | -999 |
| 2:15 AM 12/8 | 6.1 | -999 |
| 2:00 AM 12/8 | 6.09 | -999 |
| 1:45 AM 12/8 | 6.1 | -999 |
| 1:30 AM 12/8 | 6.09 | -999 |
| 1:15 AM 12/8 | 6.1 | -999 |
| 1:00 AM 12/8 | 6.09 | -999 |
| 12:45 AM 12/8 | 6.09 | -999 |
| 12:30 AM 12/8 | 6.1 | -999 |
| 12:15 AM 12/8 | 6.09 | -999 |
| 12:00 AM 12/8 | 6.1 | -999 |
| 11:45 PM 12/7 | 6.09 | -999 |
| 11:30 PM 12/7 | 6.09 | -999 |
| 11:15 PM 12/7 | 6.09 | -999 |
| 11:00 PM 12/7 | 6.09 | -999 |
| 10:45 PM 12/7 | 6.09 | -999 |
| 10:30 PM 12/7 | 6.09 | -999 |
| 10:15 PM 12/7 | 6.09 | -999 |
| 10:00 PM 12/7 | 6.09 | -999 |
| 9:45 PM 12/7 | 6.09 | -999 |
| 9:30 PM 12/7 | 6.09 | -999 |
| 9:15 PM 12/7 | 6.09 | -999 |
| 9:00 PM 12/7 | 6.09 | -999 |
| 8:45 PM 12/7 | 6.09 | -999 |
14' -
There is widespread flooding of lakeside homes and roads in the Lake Koshkonong area including Vets Lane, Blackhawk Island Road and Oxbow Bend Road.
13' -
There is widespread flooding of lakeside homes and roads in the Lake Koshkonong area including Vets Lane, Blackhawk Island Road and Oxbow Bend Road.
12' -
There is widespread flooding of lakeside homes and roads in the Lake Koshkonong area including Vets Lane, Blackhawk Island Road and Oxbow Bend Road.
11.3' -
There is knee-deep water over Blackhawk Island Road. Lamp Road on west side of river also becomes flooded. Lake Koshkonong merges with Mud Lake to the east of Lake Koshkonong.
11' -
In the Town of Lake Koshkonong, floodwaters affect Vets Lane, Blackhawk Island Road, and Oxbow Bend Road. There is widespread flooding of roads and docks in the Town of Koshkonong and Town of Sumner including Vets Lane, Blackhawk Island Road and Oxbow Bend Road.
10.5' -
Floodwaters reach Oxbow Bend Road in the area of the gage on the east side of the lake.
10' -
Floodwaters affect homes and boat docks in the Blackhawk Island area of Lake Koshkonong on the north side of the lake. Floodwaters spread over low spots on Blackhawk Island Road in the area where the Rock River enters the lake.
9.5' -
Water is into low lying areas along Lake Koshkonong.
9' -
Water spreads into low lying areas along Lake Koshkonong.
| Date | Stage (ft) |
|---|---|
| Jun 21, 2008 | 15.13 |
| Apr 22, 2013 | 12.35 |
| Apr 25, 1993 | 12.23 |
| Apr 18, 2008 | 11.65 |
| Sep 12, 2018 | 11.62 |
| Mar 25, 2019 | 11.5 |
| Jun 5, 2004 | 11.49 |
| Mar 29, 2009 | 11.37 |
| Jul 31, 2010 | 11.17 |
| Oct 15, 2018 | 11.07 |
| Jun 7, 2000 | 11.02 |
| Oct 15, 2019 | 11.02 |
| Oct 15, 2019 | 10.95 |
| Apr 7, 2007 | 10.58 |
| Aug 30, 2007 | 10.46 |
| May 20, 2018 | 10.33 |
| Jul 7, 2024 | 10.1 |
| Mar 30, 2011 | 10.09 |
| May 2, 2009 | 10.02 |
| Jun 30, 2013 | 10.02 |
Data provided by the National Weather Service.
