Percentage of Surface Drinking Water from Intermittent,
Ephemeral, and Headwater Streams in Indiana
Legend: This map highlights
regional patterns of dependence
on intermittent, ephemeral, and
headwater streams for surface
drinking water in Indiana. In
Indiana, 2,330 total miles of
streams provide water for surface
water intakes supplying public
drinking water systems; of this,
1,158 miles, or 50%, are
intermittent, ephemeral, or
headwater streams. Over 1.7
million people in Indiana 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 length of intermittent,
ephemeral, and headwater
streams to total stream length
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.
South Bend
bort Wayne
Intermittent, ephemeral, and
headwater stream miles as
percentage of total stream
miles contained in all SPAs
for a given county

1 1 0%

1 1 27% - 44%

1 1 45% - 56%

H 57% - 69%

70% - 86%

87% - 99.93'

I	| No Data