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River report

Mermentau River Flow Today

As of November 11, 2026 at 1:15 AM, the Mermentau River is flowing at 656 cfs at Mermentau, LA — 114% of normal for the date and up 14% in 24 hours. ❤ Favorite

USGS gauges
1 1 reporting · upstream → down
Mermentau River At Mermentau: 114% of normal
Typical gauge
114% of normal for the date
0%normal200%
Biggest flow now
656cfs Mermentau
Updated
Nov 11, 1:15 AM
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River briefing · Nov 11, 2026

Mermentau River conditions today

Where the river is running versus normal, what’s rising or dropping, and what it means for a trip — built from the live USGS readings below.

At Mermentau, the Mermentau River is running 656 cfs — 114% of normal, up 14% since yesterday. Along the river, 1 of 1 reporting gauges are above normal (the typical gauge is at 114% of normal).

In the last 24 hours the river is rising at Mermentau (+14%).

Headwaters to mouth

How the Mermentau River compares to normal

Every reporting gauge from the top of the river to the bottom: bar length is today’s flow, colour is percent of normal for the date.

Flow along the river, upstream to downstream

  1. Mermentau1 ft 656 cfs114%

Bar length uses a square-root scale so small headwater flows stay visible next to big downstream ones. Colour: <50% 50–90 90–110 110–150 150%+ of normal.

Where every gauge sits

One dot per Mermentau River streamgauge, placed by its own percent of normal. The line is the typical gauge (114%).

Typical gauge 114%
0%50%100% · normal150%200%+
Much below normal0Below normal0Near normal0Above normal1Much above normal0

Mermentau River flow report

1 gauge
Streamgage Streamflow % of normal 24h Gage height To flood stage Elevation
Mermentau River At Mermentau LA
Nov 11, 1:15 AM · USGS 08012150
656 cfs 114% +14% 2.19 ft 1.8 ft below 1 ft

USGS provisional data. Readings are in each gauge’s local time; gauges silent for more than 3 days are marked “Last reported”. Tap any gauge for its hydrograph, forecast and history.

History

Mermentau River streamflow over time

Daily total flow across every monitored gauge on the river (this total last updated earlier; the live gauge readings above are current).

About this river

Mermentau River

The Mermentau River is a 72-mile-long waterway located in southwestern Louisiana. It was named after the Mermentau Native American tribe. The river has a rich history dating back to the early 1800s when it was used as a primary transportation route for goods such as rice and sugar. The river is fed by several tributaries and is known for its diverse ecosystem, which includes cypress trees, alligators, and bald eagles. The river is also home to several reservoirs and dams, including the Mermentau River Dam and the Bayou Plaquemine Brule Ridge Reservoir. These dams help to control water flow and provide recreational activities such as fishing, boating, and camping. The river also plays an important role in agriculture, providing irrigation for crops such as rice and corn.

FAQ

About the Mermentau River

How is the Mermentau River flowing right now?

As of November 11, 2026, the Mermentau River is flowing at 656 cfs at Mermentau, LA, about 114% of normal for the date. Every gauge’s live reading is in the table above.

Is the Mermentau River running high or low?

The typical gauge on the Mermentau River is at 114% of normal for the date. Above 100% means higher than the historical average for this calendar day; below 100% means lower. The profile above shows which reaches are high or low.

What is flood stage on the Mermentau River?

The National Weather Service sets flood stages for Mermentau (4.0 ft). The table shows how far each gauge is below its flood stage right now.

Where does the data come from?

Discharge and gage height are from the USGS National Water Information System; flood stages from the National Weather Service. The history chart sums every monitored gauge on the river.

Can I get alerts for a gauge?

Yes — open any gauge from the table, favorite it in the Snoflo app and set a flow threshold.

More river levels

Rivers in Louisiana

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