Percentage of Surface Drinking Water from Intermittent,
Ephemeral, and Headwater Streams in Maine
[Presque Isle
| Farmington
fAugustaj
I Lewis ton
Portland
Biddeford
Key:
Intermittent, ephemeral, and
headwater stream miles as
percentage of total stream
miles contained in all SPAs
for a given county
22% - 44%
45% - 56%
57% - 69%
94% - 100%
No Data
0 12.5 25
100
I Miles
Legend: This map
highlights regional patterns
of dependence on
intermittent, ephemeral, and
headwater streams for
surface drinking water in
Maine. In Maine, 2,306 total
miles of streams provide
water for surface water-
intakes supplying public
drinking water systems; of
this, 1,265 miles, or 55%, are
intermittent, ephemeral, or
headwater streams. Over
450,000 people in Maine
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.

-------