Percentage of Surface Drinking Water from Intermittent,
Ephemeral, or Headwater Streams in South Carolina
+
Key:
Intermittent, ephemeral, and
headwater stream miles as
percentage of total stream
miles contained in all SPAs
for a given county
8% - 44%
45% - 56%
57% - 61%
100%
No Data
Rock Hill
Greenville
Anderson
Columbia
Myrtle Beach
Aiken
Summerville
Mount Pleasant
Charleston
Beaufort
Hilton Head Island
Legend: This map highlights regional patterns of dependence on
intermittent, ephemeral, and headwater streams for surface drinking water
in South Carolina. In South Carolina, 5,660 total miles of streams provide
water for surface water intakes supplying public drinking water systems; of
this, 2,888 miles, or 51%, are intermittent, ephemeral, or headwater
streams. Over 1.9 million people in South Carolina receive drinking water
from public drinking water systems that rely at least in part on
intermittent, ephemeral, or headwater streams. This analysis compared the
stream lengdi of intermittent, ephemeral, and headwater streams to total
stream lengdi within all mapped Source Protection Areas (SPAs) for each
county. A SPA is an area upstream from a drinking water source or intake
that contributes surface water flow to the drinking water intake during a
24-hour period. This is based on data that generally do not include streams
less than one mile in length. Intermittent streams are streams containing
water for only part of the year. Ephemeral streams flow in response to
precipitation events. First-order streams have been used to represent
headwater streams.
Data Sources: National Hydrography Dataset Plus at medium resolution;
Federal Safe Drinking Water Information System 4th Quarter 2006 Data.
0
10
20
40
60
80

Q-

-------