Web Portal Changes:

• Attention: Technicians are currently working to bring Precipitation datasets back to full capability after the April 16 outage.
• NWPS - water.noaa.gov - Officially operational on Wednesday, March 27th, 8-9am EDT
• AHPS - water.weather.gov- Scheduled operations ends on Tuesday, May 28th, 2024 - the pages will automatically redirect to water.noaa.gov until May 28, 2025.
• Other Important URL changes - Service Change Notice 24-29 

Please visit https://www.weather.gov/owp/operations for more information.

Weather Forecast Office Chicago, IL

North Central River Forecast Center

Hydrograph

River at a Glance

Download

Auto Refresh: OFF

Printable Image About this graph Tabular Data (UTC) Tabular Data (CDT) Datum: NAVD88 Metadata

NOTE: Graphical forecasts are not available for the Mainstream Deep Tunnel at McCook Reservoir. During times of high water, forecast crest information can be found in the text products.

Default Hydrograph Scale to Flood Categories   Return to Area Map

Downstream Gauge

Flood Categories (in feet) Not Available Historic Crests (1) -35.00 ft on 05/06/2019 (2) -38.90 ft on 05/21/2020 (P): Preliminary values subject to further review. Recent Crests Currently none available. Low Water Records Currently none available.

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

If you notice any errors in the below information, please contact our Webmaster
-40	McCook Reservoir reaches 100 percent of full storage. Combined sewer overflow event likely.
-95	McCook Reservoir reaches 75 percent of full storage. Combined sewer overflow event possible.
-155	McCook Reservoir reaches 50 percent of full storage.
-215	McCook Reservoir reaches 25 percent of full storage.
-280	McCook Reservoir is empty, 0 percent of full storage.

About This Location

Latitude: 41.777500° N, Longitude: 87.836600° W, Horizontal Datum: NAD83/WGS84 River Stage Reference Frame Gauge Height Flood Stage Uses NWS stage 0 ft Not Available 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 579.20 529.20 Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps NGVD 29 579.48 529.48 Older USGS topographic maps, NGVD29 benchmarks MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks Other 0.0 -50.0 Chicago City Datum

Additional Information

McCook Reservoir Webcam TARP Reservoir Storage Levels

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