Grand Bayou Reservoir

Name: Grand Bayou Reservoir (Louisiana) water level
Creator: U.S. Geological Survey

at spillway near Coushatta, LA · Louisiana · USGS gauge

Grey bar: recent range 133.6–134.3 ft.

Water level · NGVD29

133.52FT

Gauge elevation · no % full published

7 days −0.15 ft30 days −0.77 ft

Reading for Oct 25, 2026, 18:30 UTC · page refreshed Oct 25, 21:53 UTC
Source: U.S. Geological Survey (Water Data for the Nation)

Worth going today?This Afternoon

Looks good

Light wind, dry

Wind5 mph

Rain0%

Temp81°F

Level133.5 ft

This AfternoonMostly Sunny · 81°F
E 5 mph · rain 0%

TonightMostly Cloudy · 52°F
NE 0 to 5 mph · rain 0%

NWS forecast for the gauge location. Good = wind ≤ 10 mph and rain ≤ 30%; storms are flagged. Not safety advice – check local conditions, closures and warnings.

Level history

Last 30 days of daily means.

Field notes

As of Oct 25, 2026, Grand Bayou Reservoir stood at 133.52 (NGVD29) ft.

Over the past 7 days the lake has been falling (−0.15 ft), and it is −0.77 ft over 30 days.

Readings come from the USGS gauge “Grand Bayou Reservoir at spillway nr Coushatta, LA”. Gauge elevations are not directly comparable between lakes because each uses its own datum.

Lake facts

Gauge / station	Grand Bayou Reservoir at spillway nr Coushatta, LA
Elevation datum	ft (NGVD29)
Gauge location	31.9988, -93.2133

Nearby lakes

Lake Bistineau26 mi NW133.43 ft−0.18 ft Nantachie Lake37 mi SE93.78 ft−0.26 ft Toledo Bend Reservoir46 mi SW · TX167.66 ft−0.12 ft Cross Lake49 mi NW169.90 ft−0.09 ft Cypress Bayou Lake52 mi NW177.72 ft−0.11 ft

Common questions

Is Grand Bayou Reservoir rising or falling?

Over the last 7 days it changed −0.15 ft and over 30 days −0.77 ft.

How full is Grand Bayou Reservoir?

USGS publishes the water surface elevation for this gauge but not a percent-full figure, so we don't show one rather than estimate it.

How often is this page updated?

The page is rebuilt automatically every day from USGS's published data. Values can be revised later by the source agency.

Where does the data come from?

The U.S. Geological Survey's Water Data API (api.waterdata.usgs.gov), which publishes readings from USGS and partner gauges. Forecasts come from the National Weather Service.

Latest instantaneous reading; 7-day, 30-day and year-ago changes compare readings at the same hour. USGS data are provisional and subject to revision. This page is not affiliated with or endorsed by the USGS. See data sources.