Mermentau River Flow Today
As of October 2, 2026 at 5:15 AM, the Mermentau River is flowing at 411 cfs at Mermentau, LA — 48% of normal for the date and up 64% in 24 hours. ❤ Favorite
Mermentau River map
See the Mermentau River on a live map
Every gauge, dam and paddle run on the river, one tap each:
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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 411 cfs — 48% of normal, up 64% since yesterday. Along the river, 1 of 1 reporting gauges are below normal (the typical gauge is at 48% of normal).
In the last 24 hours the river is rising at Mermentau (+64%).
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
- Mermentau1 ft 411 cfs48%
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 (48%).
Mermentau River flow report
| Streamgage | Streamflow | % of normal | 24h | Gage height | To flood stage | Elevation |
|---|---|---|---|---|---|---|
|
Mermentau River At Mermentau LA
Oct 2, 5:15 AM · USGS 08012150 |
411 cfs | 48% | +64% | 1.99 ft | 2.0 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.
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).
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.
About the Mermentau River
How is the Mermentau River flowing right now?
As of October 2, 2026, the Mermentau River is flowing at 411 cfs at Mermentau, LA, about 48% 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 48% 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.