Web Portal Changes: The Advanced Hydrologic Prediction Service (AHPS) hosted at https://water.weather.gov will be replaced by the National Water Prediction Service (NWPS), with a target of March 2024. Existing AHPS content and features will be preserved and expanded within NWPS.

Experimental National Water Center Products: The National Hydrologic Discussion, Area Hydrologic Discussion, and Flood Hazard Outlook, and real-time geospatial services depicting River Forecast Center and National Water Model forecasts, continue to be accessible via https://www.weather.gov/owp/operations, as described in the StoryMap here.

Weather Forecast Office Chicago, IL

North Central River Forecast Center

Hydrograph

River at a Glance

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Inundation Mapping

Probability Information Weekly Chance of Exceeding Levels Chance of Exceeding Levels During Entire Period Short-term Probabilistic Guidance (Experimental) Not Available

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Printable Image About this graph Tabular Data (UTC) Tabular Data (CDT) Datum: NGVD29 Metadata

NOTE: River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 24 hours into the future from the forecast issuance time. NOTE: Forecasts for the Illinois River at Ottawa are issued as needed during times of high water, but are not routinely available.

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Upstream Gauge

Downstream Gauge

Flood Categories (in feet) Major Flood Stage: 471 Moderate Flood Stage: 467 Flood Stage: 463 Action Stage: 461 Low Stage (in feet): 456.5 Historic Crests (1) 473.72 ft on 04/19/2013 (2) 472.59 ft on 05/19/2020 (3) 472.21 ft on 09/16/2008 (4) 471.49 ft on 02/22/2018 (5) 470.83 ft on 05/02/2019 Show More Historic Crests (P): Preliminary values subject to further review. Recent Crests (1) 472.59 ft on 05/19/2020 (2) 470.83 ft on 05/02/2019 (3) 471.49 ft on 02/22/2018 (4) 463.65 ft on 10/16/2017 (5) 464.10 ft on 07/23/2017 Show More Recent Crests (P): Preliminary values subject to further review. Low Water Records (1) 458.62 ft on 11/26/2018 (2) 458.65 ft on 01/22/2019 (3) 458.82 ft on 09/03/2017 For more information on your flood risk go to www.floodsmart.gov. Show FEMA's National Flood Hazard Layers FEMA's National Flood Hazard Layers not showing? Why aren't the FEMA National Flood Hazard Layers showing on the ESRI Map? Possible reasons: There are no FEMA National Flood Hazard Layers for the location which you are viewing on ESRI Maps. The FEMA Web Mapping Service (WMS) is down. Note: Your zoom level may have changed. ESRI's zoom levels must be between 14 and 16 to show National Flood Hazard layers.

Zoom Level:16 Legend FEMA Layer Gauge Location Disclaimer 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.

Flood Impacts & Photos

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476	Water reaches the top of the levee at Ottawa High School.
475.5	Backwater causes the Fox River to reach the top of the flood protection wall south of Main Street near Ottawa High School. Water inundates lower-level of residences at Heritage Harbor east of Ottawa.
474.5	Backwater causes the Fox River to reach the top of the levee at Ottawa High School.
474	Structures threatened at Shoreline Boat Club in Ottawa. Main Street at Fox River in Ottawa is threatened and may be closed, blocking the last primary evacuation route for east Ottawa. Water overtops the berm at Waste Water Treatment Plant.
472	West parking lot of St. Elizabeth Medical Center in Ottawa is inundated.
471.5	Water reaches top of levee at Ottawa Waste Water Treatment Plant. Backwater causes the Fox River to inundate the YMCA parking lot in Ottawa.
470	Shabbona Street near Ottawa High School is inundated. St. Elizabeth Medical Center property in Ottawa is threatened including the loading dock areas.
469	Backwater causes the Fox River to reach bankfull near the YMCA in Ottawa.
468	River Rescue structure threatened in Ottawa.
467	Green Street near Shoreline Boat Club in Ottawa is inundated, blocking a primary evacuation route for east Ottawa.
466.5	Low-lying sections of Fox River Park in Ottawa are inundated including Hudson Street River Walk. St. Clair Street is threatened in Ottawa.
465.5	Low-lying property near St. Elizabeth Medical Center is threatened. Marquette High School football threatened.
465	Harbor Walk in Heritage Harbor east of Ottawa is inundated.
464	Backwater causes the Fox River to reach bankfull near St. Elizabeth Medical Center in Ottawa.
462.5	Roadway entrance to Allen Park threatened in Ottawa. Allen Park west boat ramp inundated in Ottawa.
461	River Rescue boat dock inundated in Ottawa.
Photos (1) Gage equipment located on top of levee near mouth of Fox River. (2) Levee at Ottawa High School. (3) Looking downstream from atop levee 9/3/2009. Gage height 459.80 ft. (4) Looking upstream from atop levee 9/3/2009. Gage height 459.80 ft.

Low Water Impacts

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456.5	Low water levels begin to impact shipping interests along the river.

About This Location

Latitude: 41.344444° N, Longitude: 88.839167° W, Horizontal Datum: NAD83/WGS84 River Stage Reference Frame Gauge Height Flood Stage Uses NWS stage 0 ft 463 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps Vertical Datum Elevation (gauge height = 0) Elevation (gauge height = flood stage) Elevation information source NAVD88 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps NGVD 29 Not Available 463 Older USGS topographic maps, NGVD29 benchmarks MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks Other Not Available Not Available   Current/Historical Observations: Corps of Engineers (COE) Info for Ottawa

Additional Information

How much forecast precipitation was used for the current river forecast?

Resources

Hydrologic Resources Text Products Past Precipitation Forecast Precipitation River Forecast Centers River Stage Summary USGS WaterAlert Gauge Notifications Drought Information Snow Cover Information Flood Safety NWS Chicago Hydrology Program Hydrology of North Illinois and Northwest Indiana

Additional Resources Area Hydrographs NWS Precipitation and River Forecasting AHPS Iframes for Developers Mobile iNWS for emergency management

Collaborative Agencies 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 Chicago Weather Forecast Office 333 W. University Dr. Romeoville, IL 60446 (815) 834-1435 Ask Questions/Webmaster Page last modified: 2-Nov-2020 7:29 PM Disclaimer Credits Glossary Privacy Policy About Us Career Opportunities