U.S. Department of the Interior
U.S. Geological Survey
News Release
August 22, 2006 Diane Noserale 703-648-4333 dnoseral@xxxxxxxx
Decline in Apalachicola River Levels
Greater than Previously Thought
Editors: The
report, “Water-Level Decline in the Apalachicola River, Florida, from
1954 to 2004, and Effects on Floodplain Habitats,” is available at:
http://pubs.water.usgs.gov/sir2006-5173
Declines in water levels in the
Apalachicola River in Florida’s panhandle occurred over the past 50 years
as a result of erosion of the river channel and decreased spring and summer
flow from upstream, according to a report released today by the U.S. Geological
Survey (USGS). These declines are greater than previously thought and have
caused drier conditions in wetland habitats in the adjacent river floodplain.
Consequently, less water now moves into the hundreds of miles of floodplain
streams, sloughs, and lakes that are essential to maintain healthy populations
of fishes, mussels, and other aquatic life.
“Unfortunately, the largest drop
in water levels has occurred during spring and summer, which is the most
critical time of year for fish reproduction, wetland tree growth, and many
other important biological processes,” said USGS scientist Helen Light,
the lead author of the report.
Erosion along the river bed and
banks occurred first, and was apparently caused by construction of a dam
at the Georgia-Florida border in 1954 and by extensive navigation improvements
-- river straightening, dredging, and woody-debris removal -- during the
next 2-3 decades.
“Previous studies suggested that
declines caused by channel widening and deepening were limited primarily
to the upper 30 miles of the river,” said Light, “but we now know that
nearly the entire 86 miles of the non-tidal Apalachicola River and floodplain
have been substantially altered by water-level declines caused by channel
erosion.”
Channel erosion stabilized after
the late 1970s, but spring and summer water levels continued to decline
in recent decades because of seasonal decreases in flow from the upstream
watershed. Less flow during the spring and summer is likely caused by a
combination of natural climatic changes and a variety of human activities
in the Apalachicola-Chattahoochee-Flint (ACF) River Basin, including agricultural
irrigation, municipal water use, flow regulation, and reservoir evaporation.
The ACF River Basin, which covers
one-quarter of the state of Georgia, extends from headwaters in northern
Georgia through southwestern Georgia and eastern Alabama to the Florida
panhandle, discharging into the Gulf of Mexico at the town of Apalachicola.
The area for this study included the non-tidal portion of the Apalachicola
River from the Georgia-Florida line downstream to the beginning of the
tidal reach about 20 miles upstream from Apalachicola Bay.
This report is the result of an
interdisciplinary study by USGS integrating hydrology, geomorphology, and
biology.
The USGS serves the nation by providing
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energy, and mineral resources; and enhance and protect our quality of life.
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Diane Noserale
Media Relations, Eastern Region
U.S. Geological Survey
150 National Center
Reston, VA 20192
phone: 703-648-4333
fax: 703-648-4588
