Green River at Mammoth Cave water level

Name: Green River at Mammoth Cave water level (U.S. Geological Survey)
Creator: U.S. Geological Survey
License: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits

River gauge, Green River, Kentucky, United States

Directions

Normal for mid-October

Water level

9.37ft Down 0.36 ft over the last 24 hours

Measured Oct 18, 2026, 07:00 PM EDT (54 min ago)

Flow: 517 cfs

History

7 days 30 days 1 year Years compared

20252026

Water level Normal range (10–90 %) Forecast Minor flood stage

The forecast expects the river to rise to 9.50 ft by Sunday, October 18 at 02:00 PM. Issued Sunday, October 18 at 09:37 AM by NOAA National Weather Service.

What this means

Water levels are unremarkable at Green River at Mammoth Cave, where the gauge shows 9.37 ft.

That puts it 0.86 ft above the median of 8.51 ft for mid-October, based on 11 years of readings. It is 22.63 ft below the flood stage of 32.00 ft. A year ago it stood at 8.50 ft (+0.87 ft).

It is still going down, by 0.36 ft over the past 24 hours. The forecast expects the river to rise to 9.50 ft by Sunday, October 18 at 02:00 PM. The 30-day range is 8.45 ft – 9.73 ft.

Compared with 11 years of daily readings for this time of year. How to read levels

Key numbers

Median for this date: 8.51 ft0.86 ft above the median for this date
Normal for this date: 5.86 ft – 19.05 ft8 years in 10 fall in this range (11 years of records)
Same day last year: 8.50 ft+0.87 ft
Lowest and highest in 30 days: 8.45 ft – 9.73 ft
Lowest and highest in 12 months: 8.45 ft – 36.41 ft
Highest on record: 59.66 ftApril 6, 2025
Forecast peak: 9.50 ftSunday, October 18 at 02:00 PM

Paddling and fishing conditions

Most paddlers and anglers will find the river in good shape at this stage.

For reference, flood stage is 32.00 ft.

What happens at each level

52.00 ft: Cave tours that use the lower levels of the cave are closed.
42.00 ft: Echo River Spring Trail and parking lot are under water and not accessible.
32.00 ft: Green River Ferry closes to all traffic due to high water.
20.10 ft: Launching of paddle craft is prohibited.
20.00 ft: Green River Ferry closes to RV and trailer traffic due to high water. Heavy loads will be at the judgment of the ferry operator considering the 12 ton load limit of ferry. Backcountry camping on the Green River floodplain is prohibited.
9.37 ft: Right now

Impact statements from the U.S. National Weather Service.

Highest crests on record

Rank	Level	Date
1	59.66 ft	April 6, 2025
2	52.46 ft	February 18, 2025
3	50.94 ft	March 3, 2021
4	42.62 ft	February 26, 2019
5	38.04 ft	December 19, 2019
6	34.60 ft	February 12, 2018

Weather at the gauge

The forecast is not available right now.

Sunrise 07:56 AM Sunset 07:05 PM Daylight 11 hr, 9 min First quarter 54%

Map

Other gauges on the Green River

Gauge	Level	Compared with normal	24 hours	Distance
Green River near McKinneyRiver gauge, Green River	3.8 cfs	Normal	−0.5 cfs	77 mi
Green River near CampbellsvilleRiver gauge, Green River	94.10 ft	Low	±0	42 mi
Green River at GreensburgRiver gauge, Green River	1.07 ft	No reference yet	−0.02 ft	34 mi
Green River at MunfordvilleRiver gauge, Green River	2.98 ft	Below flood stage	−0.17 ft	14 mi
Green River at Highway 259 at BrownsvilleRiver gauge, Green River	17.82 ft	No reference yet	−0.15 ft	9 mi
Green River at Lock 4 at WoodburyRiver gauge, Green River	3.18 ft	Below flood stage	+0.11 ft	28 mi
Green River at RochesterRiver gauge, Green River	29.02 ft	Below flood stage	+0.07 ft	43 mi
Green River at ParadiseRiver gauge, Green River	0.86 ft	Very low	−0.02 ft	48 mi
Green River at RockportRiver gauge, Green River	0.89 ft	No reference yet	+0.03 ft	50 mi
Green River at LivermoreRiver gauge, Green River	3.80 ft	Very low	+0.04 ft	60 mi
Green River at Lock 2 at CalhounRiver gauge, Green River	10.01 ft	Below flood stage	+0.04 ft	68 mi
Green River at Lock 1 at SpottsvilleRiver gauge, Green River	1,060 cfs	Low	+79.0 cfs	85 mi

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
Nolin River at KyrockRiver gauge, Nolin River	17.38 ft	Very low	−0.01 ft	10 mi
Nolin Lake near KyrockLake, Nolin Lake	514.61 ft	Below flood stage	−0.02 ft	10 mi
Bacon Creek near PricevilleRiver gauge, Bacon Creek	16.3 cfs	Normal	−1.1 cfs	14 mi
Barren River Lake near FinneyLake, Barren River Lake	550.81 ft	Below flood stage	−0.05 ft	20 mi
Barren River at Bowling GreenRiver gauge, Barren River	4.09 ft	Below flood stage	−0.06 ft	21 mi
Drakes Creek near AlvatonRiver gauge, Drakes Creek	4.13 ft	Below flood stage	−0.07 ft	25 mi
Nolin River at White MillsRiver gauge, Nolin River	85.3 cfs	Normal	−18.7 cfs	27 mi
Caney Creek near Horse BranchRiver gauge, Caney Creek	0.0 cfs	Low	±0	36 mi

Questions and answers

How does the Green River at Mammoth Cave compare with last year?

It is 0.87 ft higher than on the same day last year, when the reading was 8.50 ft.

What is flood stage for the Green River at Mammoth Cave?

The official flood stage is 32.00 ft. The level is currently 22.63 ft below it.

What is a normal level for the Green River at Mammoth Cave in mid-October?

The median for mid-October is 8.51 ft. In 8 years out of 10 the reading falls between 5.86 ft and 19.05 ft, based on 11 years of records.

Is gage height the same as water depth?

No. Gage height is measured from a fixed reference point chosen by the agency, so a reading of 10 ft does not mean the river is 10 ft deep.

What is the water level of Green River at Mammoth Cave today?

On Oct 18, 2026, 07:00 PM EDT, the water level was 9.37 ft. Down 0.36 ft over the last 24 hours.

Is Green River at Mammoth Cave rising or falling?

Down 0.36 ft over the last 24 hours. Up 0.60 ft over the last 7 days.

Is the level of Green River at Mammoth Cave normal?

Normal for mid-October. Compared with 11 years of daily readings for this time of year.

For specialists

Station codes, datum, parameters, data quality and downloads

Operator: U.S. Geological Survey
Station code: usgs:03309000 (Agency page)
Coordinates: 37.18005, -86.11248 (WGS84)
Vertical datum: NAVD88
Update interval: every 15 minutes
Licence: Public domain. Data: U.S. Geological Survey (USGS), provisional data subject to revision

Published series

Parameter	Last value	Time (UTC)	Quality
Water level	9.37 ft	2026-10-18 23:00	Provisional
Flow	517 cfs	2026-10-18 23:00	Provisional

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How to cite

U.S. Geological Survey: Green River at Mammoth Cave (usgs:03309000). Accessed October 18, 2026 via Nivelmap, https://nivelmap.com/en/united-states/kentucky/green-river-at-mammoth-cave

How we check values

Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.

Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer