USGS Water-Year Summary 2024

03309000 GREEN RIVER AT MAMMOTH CAVE, KY

LOCATION - Lat 37°10'48", long 86°06'45" referenced to North American Datum of 1927, Edmonson County, KY, Hydrologic Unit 05110001, on right bank, upstream side of road (Echo River Road) at ferry landing, five hundred feet downstream from Echo River, 0.75 miles southwest of Mammoth Cave, and at mile 197.2.

DRAINAGE AREA - 2,020 mi² of which 481 mi² probably is noncontributing.

SURFACE-WATER RECORDS

PERIOD OF RECORD - July 1938 to September 1950. October 1, 2003 to September 30, 2007.  November 2017 to present.

GAGE - Water-stage recorder with telemetry.  Datum of gage is 409.35 ft above the North American Vertical Datum of 1988.

COOPERATION - Mammoth Cave National Park.

REMARKS - Flow affected by releases from Green River Lake, 100 miles upstream.

EXTREMES OUTSIDE PERIOD OF RECORD - Maximum stage known, 52.5 feet, January 24, 1937, at former site (discharge, 75,000 ft³/s). Flood of 1913 reached a stage of 50.5 feet.

WATER-QUALITY RECORDS

PERIOD OF RECORD - Water Temperature:  November 14, 2017 to current.

Temperature, Specific Conductance, Dissolved Oxygen, pH, and Turbidity:  August 2003 to June 2007.

PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: August 2003 to June 2007. pH: August 2003 to June 2007. WATER TEMPERATURE: August 2003 to June 2007. DISSOLVED OXYGEN: August 2003 to June 2007. TURBIDITY: August 2003 to June 2007.

COOPERATION - Mammoth Cave National Park and Western Kentucky University.

INSTRUMENTATION - Temperature thermister.

REMARKS - SPECIFIC CONDUCTANCE: Record, considered of good quality, was complete, except for period June 13-30, when the sensor went dry due to extreme low stage. pH: Record, considered of good quality, was complete, except for June 13-23, 26-27, 30 when the sensor went dry due to extreme low stage. WATER TEMPERATURE: Record, considered of good quality, was complete, except for period June 13-22, when the sensor went dry due to extreme low stage. DISSOLVED OXYGEN: Record, considered of fair quality, was complete, except for November 11-21, 2006, outside criteria range, December 17, 2006 to January 5, 2007, when membrane integrity was compromised and a gradual degradation of the data was observed through the period, March 14-21, when it appears that the sensor was manually set to the reference value with a compromised membrane, and June 30, 2007, when no data was collected. Data quality dropped off quickly after the inspection on March 14. TURBIDITY: Record, considered of fair quality, was complete, except for December 7-22, 2006, due to sensor malfunction, and June 14, 26-30, 2007, when the sensor sporadically lost contact with the water, due to extreme low stage.

EXTREMES FOR PERIOD OF RECORD - SPECIFIC CONDUCTANCE: Maximum recorded, 470 microsiemens, October 25, 2004; minimum recorded, 161 microsiemens, December 2, 2005. pH: Maximum recorded, 9.0 units, June 25, 2007; minimum recorded, 6.9 units, December 7-8, 2005. WATER TEMPERATURE: Maximum recorded, 28.8°C, July 26, 2005; minimum recorded, 1.8°C, December 22, 2005. DISSOLVED OXYGEN: Maximum recorded, 17.3 mg/L, February 18-19, 2007; minimum recorded, 5.6 mg/L, August 28, 2006. TURBIDITY: Maximum recorded, 880 FNU, December 1, 2005; minimum recorded, <2.0 FNU, October 29-30, 2005, November 24-30, December 3-6, 23, 2006 and February 11-12, 2007.

EXTREMES FOR CURRENT YEAR - SPECIFIC CONDUCTANCE: Maximum recorded, 386 microsiemens, June 5, 2007; minimum recorded, 174 microsiemens, October 12, 2006. pH: Maximum recorded, 9.0 units, June 25, 2007; minimum recorded, 7.1 units, April 15, 2007. WATER TEMPERATURE: Maximum recorded, 28.2°C, June 23, 2007; minimum recorded, 2.5°C, February 18, 2007. DISSOLVED OXYGEN: Maximum recorded, 17.3 mg/L, February 18-19, 2007; minimum recorded, 6.7 mg/L, June 4-6, 2007. TURBIDITY: Maximum recorded, 310 FNU, January 8, 2007; minimum recorded, <2.0 FNU, November 24-30, December 3-6, 23, 2006, and February 11-12, 2007.