Find stream records for last fall's flooding.  Follow the instructions that appear here.

1) FIND THE SOURCE OF ILLINOIS STREAM GAGE DATA

Go to the USGS web site http://water.usgs.gov/.  Take these steps:
    * Under "NWIS Web Water Data", click "Surface Water". 
    * In the fourth paragraph under "Introduction", click the link for "Daily Streamflow Data". 
    * Under "Site Location", click "State/Territory", and then click "Submit". 
    * Under "State/Territory", select "Illinois". 
    * Finally, scroll down all the way to the bottom of the page and click "Submit".
   
This will give you a list of all the stream gages in Illinois.

2) CHOOSE A GAGING STATION

Pick a stream gage for the North Branch of the Chicago River.  These gages are as follows:
 

1.  North Branch Chicago River at Deerfield, IL 2.  WF of NB Chicago River at Northbrook, IL  (West Fork of North Branch) 3.  North Branch Chicago River at Niles, IL 4.  North Branch Chicago River at Albany Avenue at Chicago, IL 5.  Des Plaines River Near Des Plaines, IL 6.  Des Plaines River at Riverside, IL 7.  Des Plaines River at Route 53 at Joliet, IL

3) FIND THE DATA FOR YOUR GAGING STATION.

Find your gage in the list, and click on the Site Number.  This will take you to a site specifically for that particular gage. 

Here you will see graphs showing height of the water ("Gage Height") and stream flow rate ("Discharge").  In the box near the top of the page, select "Graph w/stats", and click "GO".  Now your graphs will show the historical median values as well as the real, measured values.

 

Notice the peaks that occurred during last fall's flooding!  Under each graph is a link that says, "Create a presentation-quality graph".  Click each of those links and print out the graphs.

Now, "zoom in" on the flooding event by changing the "Begin date" and "End date" boxes near the top of the page.
Print out these new graphs, too.  Notice the units of measurement!  Also note the unusual scale on the y-axis of the discharge graph.

   
Going to the area near the top titled "Available data for this site", select "SUMMARY OF ALL AVAILABLE DATA".  On this page, find and record the "Drainage Area" (given in square miles). 

4) RECORD AND HAND IN IMPORTANT INFORMATION ABOUT THE GAGE

Find and record the following information:
    a.  Drainage area (square miles) (found on the "Summary of All Available Data")
    b.  Datum of gage (example: "579.48 feet above sea level"; found on the "Summary of All Available Data")
    c.  Looking at the gage height graph for the period of the autumn flooding, determine the highest peak value.  Also determine the historical median values during this same time period. 
    d.  Looking at the stream discharge graph for the period of the autumn flooding, determine the highest peak value.  Also determine the historical median values during this same time period. 
 

Hand in the four graphs and the information listed above.