|
Survey
Methodology
In
the Skagit River basin, the WRIA and supplemental maps of Johnson
(1986) were used in conjunction with current aerial photos and topographic
maps to locate probable areas where off-channel type habitat could
exist. Referrals were also taken from other professional biologists
working in the area. Probable areas or sites were then searched
on foot usually by walking up the mapped and identified streams.
Work in this basin began in about 1990 and was complete in 2002.
The same procedure was followed in the Stillaguamish River Basin
except there were no supplemental surveys from which to work. Work
also began here in 1990 but was incomplete when funding for the
program expired in 2003. Areas excluded from consideration were
those likely to be flooded in a two-year flood event. Off-channel
areas were followed and mapped to the 20% gradient criteria that
was assumed to be the end of the anadromous zone (WDFW 2000).
When
a site was found, it was given a unique identification code. The
first two alpha characters describe the principal named stream.
The next numeric is the reach number on that stream as assigned
by principal topographic breaks. The next alpha code is either “RB”
or “LB” for right or left bank facing downstream. The last numeric
is the sequential number of that site found on that bank.
Click on map to enlarge |
Specific
habitat and description information was collected at each site including
physical site measurements, assessment of habitat quality, and location
using a traditional legal definition (section, township and range)
and Global Positioning System (GPS) coordinates. The GPS point was
the confluence of the off-channel flow with the known or previously
identified stream. Sufficient information was also taken to later
draw a detailed map of the site. The completed field form, hand
drawn map, marked location on a USGS topographic map and an aerial
photograph are all attached to the site identification code as seen
in the Arcview map document file.
Data
Limitations
Information
was collected over about a 13 year time period and earlier data
was seldom rechecked in later years. Therefore, all site descriptions
and maps reflect conditions at a point in time and accuracy now
or at a later date cannot be confirmed. Refer to the dates on the
field forms to ascertain application to your use. A new site visit
may be necessary where critical habitat conditions occur or land
use decisions are to be made. Changes in field staff through the
survey period caused minor changes in protocol so data may be slightly
inconsistent across all sites in the database. Dynamic changes in
riverine habitat in some areas may also have caused changes in habitat
conditions at some sites previously mapped. For these reasons, WDFW
cannot accept responsibility for any errors or omissions in the
data, changed conditions from those described or products produced
from its use. Every effort was made to find all remnant bits of
habitat previously undocumented but some were likely overlooked
so this information represents the minimum area available. There
are no warranties accompanying any of the information or map products.
The user accepts this database “as is” with the understanding it
was not produced for any purpose other than that stated above.
Click on map to enlarge |
Survey
Methodology
Current
aerial photos and topographic maps were used to locate probable
areas where off-channel type habitat could exist. Referrals were
also taken from other professional biologists working in the area.
Probable areas or sites were then searched on foot usually by walking
up the mapped and identified streams. Work in these basins began
in 1987 and was suspended due to budget constraints in 2003. The
earliest work in the Hoh and Clearwater basins only included the
floodplains of the mainstems. Some of these sites are no longer
in existence due to the meandering of the rivers, which reclaimed
a few. These reclaimed sites do not appear in the data or the maps.
As the inventory evolved, sites that appeared vulnerable to reclamation
by the river were not considered for surveys. Later work on the
other river basins included tributary floodplain habitat. In most
cases, off-channel sites were followed and mapped to the 20% gradient
criteria that was assumed to be the end of the anadromous zone (WDFW
2000).
When
a site was found, it was given a unique identification code. The
first one or two alpha characters describe the principal named stream.
An alpha character follows that designates which bank of the stream
is on (R or L, looking downstream). The next numeric is the reach
number on that stream as assigned by principal topographic breaks.
The last numeric is the sequential number of that site found on
that bank. For example, S-L1-01 represents the first site on the
left bank of the Sol Duc River.
As
the inventory moved into tributaries, a different code was adopted
since most streams were not named. We used the first letter of the
named mainstem and followed that with the Water Resource Inventory
Area number (WRIA) followed by R or L for right or left bank and
ending with the sequential number in that group of sites. For example,
B-0241L-01 represents the first site on the left bank of tributary
number 20.0241, which is tributary to the Bogachiel River.
Specific
habitat and description information was collected at each site including
physical site measurements, assessment of habitat quality, and location
using a traditional legal definition (section, township and range)
and Global Positioning System (GPS) coordinates. The GPS point was
the confluence of the off-channel flow with the known or previously
identified stream. Sufficient information was also taken to later
draw a detailed map of the site. The finalized data sheets, hand
drawn maps and USGS topographic maps are all attached to the site
identification code as seen in the Arcview map document file.
Data
Limitations
Information
was collected over a 16 year time period. Due to funding cutbacks,
the inventory was not completed on all tributaries so there are
gaps in the data. The Elk Creek drainage on the Calawah river was
intensively surveyed and mapped, but is not included. The PDF files
for Elk Creek are available on request, but will not show on the
maps. Many sites were rechecked at various times of the year to
determine fish use, water flow and other anecdotal information.
All site descriptions and maps reflect conditions at a point in
time and accuracy now or later cannot be confirmed. Refer to the
dates on the field forms to ascertain application to your use. A
new site visit may be necessary where critical habitat conditions
occur or land use decisions are to be made. Changes in field staff
through the survey period caused minor changes in protocol so data
may be slightly inconsistent across all sites in the database. Dynamic
changes in riverine habitat in some areas may also have caused changes
in habitat conditions at some sites previously mapped. For these
reasons, WDFW cannot accept responsibility for any errors or omissions
in the data, changed conditions from those described or products
produced from its use. Every effort was made to find all remnant
bits of habitat previously undocumented but some were likely overlooked
so this information represents the minimum area available. There
are no warranties accompanying any of the information or map products.
The user accepts this database “as is” with the understanding it
was not produced for any purpose other than that stated above. |
