Headline:
Flood Warning issued April 20 at 4:38PM CDT by NWS Milwaukee/Sullivan WI
Event:
Flood Warning
Urgency:
Immediate
Effective:
April 20, 2026 - 2:38pm
Expires:
April 21, 2026 - 2:45am
Description:
...The Flood Warning continues for the following rivers in
Wisconsin...Illinois...
Rock River At Newville affecting Rock County.
Rock River Near Lake Koshkonong affecting Rock and Jefferson
Counties.
Rock River At Fort Atkinson affecting Jefferson County.
Rock River At Afton affecting Rock and Winnebago Counties.
Rock River At Jefferson affecting Jefferson County.
Rock River At Watertown affecting Jefferson County.
ROCK RIVER near LEBANON-3 E-HWY MM BRIDGE affecting Dodge County.
* WHAT...Minor flooding is occurring and moderate flooding is
forecast.
* WHERE...Rock River near Lake Koshkonong.
* WHEN...Until further notice.
* IMPACTS...At 11.3 feet, 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.
* ADDITIONAL DETAILS...
- At 4:00 PM CDT Monday the stage was 10.9 feet.
- Bankfull stage is 9.0 feet.
- Recent Activity...The maximum river stage in the 24 hours
ending at 4:00 PM CDT Monday was 10.9 feet.
- Forecast...The river is expected to rise to a crest of 11.3
feet early Wednesday afternoon.
- Flood stage is 10.0 feet.
- Flood History...This crest compares to a previous crest of
11.4 feet on 03/29/2009.
- http://www.weather.gov/safety/flood
Instruction:
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive
cars through flooded areas.
Even 6 inches of fast-moving flood water can knock you off your feet
and a depth of 2 feet will float your car. Never try to walk, swim,
or drive through such swift water. If you come upon flood waters,
stop, turn around and go another way.
Additional information is available at www.weather.gov.
The next statement will be issued late tonight at 445 AM CDT.
Area Description:
Jefferson, WI; Rock, WI
Forcast Office:
NWS Milwaukee/Sullivan WI