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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
02423555 CAHABA RIVER NEAR HELENA, AL
LOCATION - Lat 33°17'04", long 86°52'57" referenced to North American Datum of 1927, Shelby County, AL, Hydrologic Unit 03150202, on right bank at downstream side of bridge, 0.9 mi above Trigger Creek, 3 mi west of Helena, and at mile 127.1.
DRAINAGE AREA - 335 mi².
REVISIONS HISTORY - Revisions: The maximum discharge for water years 1996, 1998, 2000, 2003, 2004, 2005, 2010, 2014, 2019, and 2020, was revised Feb. 21. 2023, based on changes to the stage-discharge rating.
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1995 to current year. Operated as a crest-stage gage October 1964 to September 1977 (annual peaks only).
GAGE -
Water-stage recorder. Datum of gage is 357.00 ft above NAVD 1988,(Reference Frame NAD_83 (2011) (EPOCH:2010.0000), (GEOID18) .
Prior to Sept 09, 2022 the Datum of Gage was 356.85 NGVD of 1929.
REMARKS - Record considered good, except for estimated periods, which were poor.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum, 22,800 ft^3/s, March 16, 1976, 34.85 feet
WATER-QUALITY RECORDS
PERIOD OF RECORD - April 2017 to current year. (Seasonal)
PERIOD OF DAILY RECORD - WATER TEMPERATURE: April 2017 to current year (Seasonal). DISSOLVED OXYGEN: April 2017 to current year (Seasonal)
INSTRUMENTATION - Water-quality monitor.
