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- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
- For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
- Not all sites have reports available for every water year.
USGS Water-Year Summary 2024
05587498 Mississippi River Pool Lock and Dam 26 at Alton,IL
LOCATION - Lat 38°53'14.3", long 90°11'02.4" referenced to North American Datum of 1983, Madison County, IL, Hydrologic Unit 07110009,
DRAINAGE AREA - --171,500 mi. sq.,approximately.
REVISIONS HISTORY - Revisions: Gage datum was updated to 399.66 ft NAVD88 on May 22, 2023, based on GNSS Level II survey using GEOID18.
SURFACE-WATER RECORDS
GAGE -
Water-stage recorder. Datum of gage is 399.66 ft above North American Vertical Datum of 1988.
