RESTON, VA, June 7, 2007 -- Despite some rainfall at the end of the month, streamflows during May in North Carolina were at or near record low levels, particularly in the western part of the state.
The U.S. Geological Survey (USGS) has been monitoring and recording streamflow for more than 100 years at many locations throughout North Carolina, including the French Broad River at Asheville, which has been continuously monitored since 1895. Streamflows at this location in May were at or below the streamflow recorded on the same date in 2002, during the most recent severe drought.
The lowest May streamflow on record was set at 3 monitoring stations with at least 30 years of record in North Carolina, with many other rivers approaching record lows. The monthly mean flow at the French Broad River at Rosman was 103 cubic feet per second, compared to a previous low of 110 cfs.
Groundwater levels also are declining across North Carolina, although the effects depend on the type of rock or sediment of specific aquifers. Water levels in the monitoring wells in Cherokee and Swain Counties are at an all-time low for May. Groundwater levels in the eastern part of the State are only slightly below normal.
Conditions across the state range from "abnormally dry" in northeastern North Carolina to "extreme drought" in the southwestern mountains of the state, according to the U.S. Drought Monitor.
Normally the lowest streamflows of the year occur in late summer, when water use demands are highest, and in the fall. If below average rainfall continues through the summer and fall, new record low flows are likely to occur in many of North Carolina's rivers.
It is difficult to compare previous droughts with the ongoing drought while it is developing. During the previous century, hydrologic droughts have affected large portions of North Carolina many times, with the most recent event from 1999-2002. The Drought of 1998-2002 in North Carolina -- Precipitation and Hydrologic Conditions documents that drought.
The USGS and its federal, state, and local cooperators maintain 270 streamgaging stations and 39 monitoring wells throughout North Carolina.
Real-time river and groundwater levels are available online.
USGS provides science for a changing world.
###
