education: resources
for k-12 teachers and students
river basins of georgia
SAVANNAH RIVER BASIN
By Gretchen Loeffler and Judy L. Meyer
The Savannah River basin includes portions of North Carolina, South Carolina,
and Georgia and flows through the Blue Ridge Mountain, Piedmont, and Coastal
Plain provinces. The Savannah River forms the boundary between South Carolina
and Georgia and begins at Hartwell Reservoir by the confluence of the
Seneca and Tugaloo Rivers. From this point, it flows southeast to the
port city of Savannah, Georgia where it empties into the Atlantic Ocean.
Above the junction of the Seneca and Tugaloo Rivers, the major headwater
streams of the Seneca River are Keowee River and Twelve Mile Creek. The
Tugaloo River is formed by the union of the Tallulah and Chattooga Rivers.
These headwater streams originate on the southern slopes of the Blue Ridge
Mountains in North Carolina and Georgia.
Flow, sediment load, and the flood plain of the Savannah River have been
modified by eleven large dams above the Fall Line, which impound over
180,000 acres of water. Below the Fall Line, dredging and channelization
have altered the historical legacy of the Savannah. As a result of its
history of modification, the Savannah lacks the vast vegetated flood plains
in the freshwater tidal zone that are characteristic of the other Georgia
estuaries, like the Altamaha River. However, the Savannah does have extensive
developments of more saline intertidal vegetational zones near the sea.
The Savannah National Wildlife Refuge seeks to protect, preserve, and
educate the public about the diversity and fragility of this river system.
Figure
1. Tidal estuaries of the Savannah River.
Stream Flow
The following table lists the stream flow data for the Savannah River.
The location of the USGS gauging station is denoted within the parentheses.
Table 1. Stream flow from USGS. Stream flow is measured in units of cubic
feet per second (cfs) flowing past a point.
| |
Savannah River (Millhaven, GA) |
| Drainage Area (square miles) |
8,620 |
| Min Daily Flow (cfs) |
4,590 |
| Mean Daily (cfs) |
14,360 |
| Max Daily (cfs) |
48,700 |
| Years of Collection |
1939-present |
Figure 2. Land cover and land use within the Savannah River Basin. Black
star denotes approximate location of the USGS gauging station. Source:
Georgia
Rivers LMER.
Land cover and land use patterns
Table 2 lists the 1998 land cover percentages for the Savannah River basin.
The Natural Resources Spatial Analysis Laboratory (NARSAL) at the University
of Georgia provided the tabular data.
Table 2. 1998 land cover statistics.
| |
Savannah River |
| Beach |
0.02% |
| Water |
3.88% |
| Suburban |
2.34% |
| Commercial |
1.81% |
| Clearcut |
7.66% |
| Mines, rock outcrops |
0.15% |
| Deciduous forest |
19.43% |
| Evergreen forest |
27.84% |
| Mixed forest |
8.70% |
| Agriculture |
19.46% |
| Wetlands |
8.71% |
Impairments to environmental health
In the late 1990s, EPA outlined significant anthropogenic and natural
threats to the health of the Savannah River system. The list encompassed
both man-made and natural problems. For example, the construction of dams
to provide hydroelectric power and to reserve surface water to sustain
municipal water requirements leads to releases of cold water with low
dissolved oxygen, which can result in massive fish mortalities below the
dam. Development in the watershed can lead to increased urban storm water
runoff, nonpoint source releases into the watershed, and loss of critical
wetland habitats. Discharges and releases from the Savannah River Site,
which was listed as a Superfund site in 1989, also threaten the health
of the Savannah. As the drought in Georgia continues, the water tables
continue to drop further beneath the surface. With the dropping water
table, there are increasing concerns over saltwater water intrusion into
groundwater supplies and the potential for an interaction with surface
water supplies. Impacts from human development, commerce, dam construction,
and natural tidal processes all threaten the health and diversity of the
Savannah River basin.
Additional information and sources
Georgia
Rivers LMER
EPA
Publication on Savannah River Basin
National
Science Center, DNR Wildlife Resources
NARSAL
maps
Savannah
National Wildlife Refuge
Environmental, Educational, and Community Action Organizations
American Rivers
Georgia
Adopt-A-Stream
Georgia Canoeing
Association
Georgia River Network
River Network
Nature
Conservancy of Georgia
Trust for Public Land
Broad
River Watershed Association
Savannah
Riverkeeper
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