FLOOD10133

• County: Statewide
• Community: State of North Carolina
• Basin: Statewide
• Title: Two Months of Flooding in Eastern North Carolina, September-October 1999: Hydrologic, Water-Quality, and Geologic Effects of Hurricanes Dennis, Floyd and Irene
• Date: 1/1/2000
• Prepared By: USGS
• Floodplain - Doc Type: Flood Documentation Report

Floods can transport tremendous
quantities of material from the land
surface into the stream system, inun-
date areas that are contaminated with
a variety of substances, flood
wastewater-treatment facilities that
may be located in or near the flood-
plain, and result in the failure of
animal waste lagoons. The large
volume of water transported during
the Hurricane Floyd flooding
demonstrated that even low concen-
trations of pollutants ean result in the
transport of extremely high loads (or
mass) of these materials through the
stream system and ultimately to the
estuaries of eastern North Carolina.
The somewhat
limited water-
quality sampling
that was con-
ducted following
Hurricane Fran
(Bales and
Childress, 1996)
proved to be very
informative
because little is
known about
water-quality
conditions during
extremely large
floods, Water-
quality samples
were collected
during the flood-
ing that followed
Hurricane Floyd
in order to better
document and
understand the
transport of nutri-
ents, metals, pes-
ticides, and other
34'
pollutants during
extreme floods; to
document load-

ings of pollutants transported to the
coastal waters; to compare Hurricane
Floyd water-quality conditions with
those resulting from Hurricane Fran;
and to provide a basis for understand-
ing possible future environmental
changes (such as aecelerated estua-
rine eutrophication) that may result
from the floods,
Floodwater-quality samples were
collected at 15 sites (fig, 13; table 6)
beginning on September 16, 1999,
following the passage of Hurricane
Floyd through the State, and continu-
ing through October 5, 1999. Five
sites on the Tar River from Tar River
(site 7) to Greenville (site 16) were

80'

79'

78'

sampled; five sites were sampled on
the mainstem of the Neuse River
from Clayton (site 22) to Fort Barn-
well (site 32) and two Neuse River
tributary sites were sampled; the
Cape Fear River at Lock I (site 40)
was sampled, as were the Northeast
Cape Fear River near Chinquapin
(site 43) and the Lumber River at
Boardman (site 45). Samples were
collected on the day ofthe peak
discharge on the Tar River from
Louisburg to Greenville (sites 8, 9,
and 16), except at Tarboro (site 14),
where the first sample was collected
2 days after the peak at 93 percent of
the peak discharge, The Tar River

77'

76'

37'

36'

35'

Figure 13. Sites at which water-quality samples were collected by the USGS in September-October
1999, following Hurricane Fioyd,

Two Months of Flooding in Eastern North Carolina. September-Dctober 1999