Summary
Total streamflow across the
Marys River
was last observed at
904
cfs, and is expected to yield approximately
1,794
acre-ft of water today; about 128%
of normal.
River levels are high.
Average streamflow for this time of year is
707 cfs,
with recent peaks last observed
on
2012-01-19 when daily discharge volume was observed at
8,922 cfs.
Maximum discharge along the river is currently at the
Marys River Near Philomath
reporting a streamflow rate of 897 cfs.
This is also the highest stage along the Marys River, with a gauge stage of
9.66 ft at this location.
This river is monitored from 3 different streamgauging stations along the Marys River, the highest being situated at an altitude of 5,950 ft, the
Marys River Below Orange Bridge Nr Charleston Nv.
River Details
| Last Updated | 2025-12-26 |
| Discharge Volume | 1,794 ACRE-FT |
| Streamflow |
904.36 cfs
-153.47 cfs (-14.51%) |
| Percent of Normal | 127.94% |
| Maximum |
8,922.0 cfs
2012-01-19 |
| Seasonal Avg | 707 cfs |
River Streamflow Levels
| Streamgauge | Streamflow | Gauge Stage | 24hr Change (%) | % Normal | Minimum (cfs) | Maximum (cfs) | Air Temp | Elevation |
|---|---|---|---|---|---|---|---|---|
|
Marys River Below Orange Bridge Nr Charleston Nv
USGS 10313400 |
8 cfs | 1.58 ft | ||||||
|
Marys R Ab Hot Springs C Nr Deeth
USGS 10315500 |
7 cfs | 2.16 ft | -6 | |||||
|
Marys River Near Philomath
USGS 14171000 |
897 cfs | 9.66 ft | -14.57 |
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile
The St. Marys River (named Saint Marys River by the USGS, and sometimes misspelled as St. Mary's River) is a 126-mile-long (203 km) river in the southeastern United States. From near its source in the Okefenokee Swamp, to its mouth at the Atlantic Ocean, it forms a portion of the border between the U.S. states of Georgia and Florida. The river also serves as the southernmost point in the state of Georgia.
The St. Marys River rises as a tiny stream, River Styx, flowing from the western edge of Trail Ridge, the geological relic of a barrier island/dune system, and into the southeastern Okefenokee Swamp. Arching to the northwest, it loses its channel within the swamp, then turns back to the southwest and reforms a stream, at which point it becomes the St. Marys River. Joined by another stream, Moccasin Creek, the river emerges from Okefenokee Swamp at Baxter, Florida/Moniac, Georgia. It then flows south, then east, then north, then east-southeast, finally emptying its waters into the Atlantic, near St. Marys, Georgia and Fernandina Beach, Florida.