The numbers are in relation to the Oshkosh Datum which is at Lat 44°00’49”, long 88°32’27” in SW 1/4 SW 1/4 sec.24, T.18 N., R.16 E., Winnebago County, Hydrologic Unit 04030201, on right bank about 400 ft downstream from U.S. Highway 45 and State Highway 26 bridge, at Oshkosh. (Between the Main St. bridge and the rail road bridge and you can find this location on our Hot Spots Map.)
This information can be used to adjust depth charts and depth sounders for the day to day and month to month variations in the water levels.
This web site will also have the schedules for the meetings on what the spring re-fill and fall drain down plans are. Thanks to RumRunner for providing the link!