Percentage of Surface Drinking Water from Intermittent,
Ephemeral, and Headwater Streams in Nevada
Key:
Intermittent, ephemeral, and
headwater stream miles as
percentage of total stream
miles contained in all SPAs
for a given county
97% - 100%
No Data
Legend: This map highlights
regional patterns of
dependence on intermittent,
ephemeral, and headwater
streams for surface drinking
water in Nevada. In Nevada,
49 total miles of streams
provide water for surface
water intakes supplying public
drinking water systems; of
this, 40 miles, or 82%, are
intermittent, ephemeral, or
headwater streams. Over
23,000 people in Nevada
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.
Carson City
Las iVegas
Henderson
0
20
40
80
120
160







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