Skip Navigation

weather.gov

NOAA - Click to go to the NOAA homepage National Weather Service Advanced Hydrologic Prediction Service NWS logo - Click to go to the NWS homepage
Navbar left image Home News Organization
Navbar End cap

Winnebago River (Northern IA) at Mason City, IA (MCWI4)


Data Type




Inundation Levels
NAVD88 Stage

1,091.5*22.0*
1,091.0*21.5*
1,090.5*21.0*
1,090.0*20.5*
1,089.5*20.0*
1,089.0*19.5*
1,088.5*19.0*
Record Crest: 18.74 ft
1,088.0*18.5*
1,087.518.0
1,087.017.5
1,086.517.0
1,086.016.5
1,085.516.0

Major Flooding Begins

1,085.015.5
1,084.515.0

Moderate Flooding Begins

1,084.014.5
1,083.514.0
1,083.013.5
1,082.513.0
1,081.512.0
1,081.011.5
1,080.511.0
1,080.010.5

Minor Flooding Begins

1,079.510.0
1,079.09.5
1,078.59.0
1,078.08.5

Near Flooding Begins

1,077.58.0
1,077.07.5
1,076.57.0
1,075.56.0

Below Flooding Begins

* = Extended rating
Weather Forecast Office Des Moines, IA North Central River Forecast Center
Hydrograph River at a Glance Download Inundation
Mapping
Loading...

Click on mapped inundation to see water depth values for that location, or hold shift and drag to zoom to area.

Current Stage:
6.5 ft at 03/28/2024 17:30:00 UTC
Selected Inundation
Mouse Location

North Arrow

Inundation Legend
Depth in feet
USGS Gauge Location Gauge Location
What is UTC time? Map Help

Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.

Gauge Information Collapse

Map Overlays

Flood Categories (in feet)
Major Flood Stage: 15.5
Moderate Flood Stage: 14.5
Flood Stage: 10
Action Stage: 8
Low Stage (in feet): -9999

Historic Crests
(1) 18.74 ft on 06/08/2008
(2) 15.70 ft on 03/30/1933
(3) 14.80 ft on 03/27/1961
(4) 14.67 ft on 05/22/2004
(5) 14.27 ft on 04/11/1965
(6) 14.07 ft on 09/22/2016
(7) 13.06 ft on 08/31/1962
(8) 12.59 ft on 04/01/1993
(9) 12.44 ft on 04/07/1951
(10) 12.25 ft on 07/08/1969
Show More Historic Crests

(P): Preliminary values subject to further review.

Recent Crests
(1) 10.91 ft on 04/13/2022
(2) 5.78 ft on 08/28/2021
(3) 7.34 ft on 03/05/2020
(4) 7.27 ft on 10/06/2019
(5) 10.42 ft on 03/20/2019
(6) 10.54 ft on 03/17/2019
(7) 12.17 ft on 09/21/2018
(8) 7.14 ft on 02/21/2017
(9) 14.07 ft on 09/22/2016
(10) 7.10 ft on 06/22/2015
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
Currently none available.

Graphical representation of flood inundation for NWS flood categories are based on steady state hydraulic modeling of water surface elevations for incremented discharges. Map shows approximate inundation areas for given water surface elevations and should not be used for navigation or permitting or other legal purposes, but strictly as a planning reference tool.

Site-specific information:
Willow Creek flow contributions have a significant influence on the magnitude and location of flooding in Mason City. The Winnebago River flood depth maps at this location are representative of a typical flooding scenario, which incorporates the most likely flow contributions from Willow Creek. Additional medium and high Willow Creek flow contribution scenarios have been provided below the main map window to supplement the typical scenario maps.

The Water Treatment Plant on 13th Street NE is protected by a floodwall, which was constructed after the flood inundation map was completed. The protection provided by the floodwall is not depicted on the flood inundation map; however, the Water Treatment Plant will remain protected by the floodwall, until the floodwall is overtopped at a stage of 21.5 ft.

Flood Impacts Collapse
If you notice any errors in the below information, please contact our Webmaster
20.5 Water overtops the floodwall at the water treatment plant...located at 13th St NE.
17.4 Water reaches bottom of railroad bridge east of Kentucky Avenue bridge.
15 This is the approximate top of levee protection. Levees run from the 12th Street Northeast bridge to 9th Street along the east bank and also from 8th Street to 6th and Hampshire Streets.
14 Water may flow over the city dikes.
12 Widespread flooding occurs along the river. Some backwater effects are possible along Willow Creek between downtown Mason City and the confluence with the Winnebago river.
11 Sandbagging occurs on the dike from 12th Street Northeast to Carolina Street.
10 There is widespread flooding of city parks and water reaches the underside of the 12th Street Northeast bridge at the piers.
8 East and west city parks are affected in the 12th Street Northeast area.
7 Low lying areas along the river are affected.
Other Data Sources Collapse
Additional Information Collapse
  • USGS 7-Day Streamflow Duration Hydrograph for this location:
    Duration Hydrograph

    Duration Hydrograph Legend


  • USGS Cumulative Streamflow Hydrograph for this location:
    Duration Hydrograph of Cumulative Streamflow
Resources Collapse
Hydrologic Resources
Additional Resources
Collaborative Agencies Collapse
The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.
NWS Information
National Weather Service
Ask Questions/Webmaster
Page last modified: 2-Nov-2020 7:34 PM
Disclaimer
Credits
Glossary
Privacy Policy
About Us
Career Opportunities
Graphical representation of flood inundation for NWS flood categories are based on steady state hydraulic modeling of water surface elevations for incremented discharges. Map shows approximate inundation areas for given water surface elevations and should not be used for navigation or permitting or other legal purposes, but strictly as a planning reference tool.