California Rapid Assessment Method for Wetlands - State Water ...

California Rapid Assessment Method for Wetlands v. 5.0.2 – Chapter 4
Table 4.3 (Continued): Rating for Landscape Connectivity for Riverine wetlands.
Rating
A
B
B
C
D
D
For Distance of 500 m Upstream of AA:
The combined total length of all nonbuffer
segments is less than 100 m for
wadeable systems (“2-sided” AAs); 50 m
for non-wadeable systems (“1-sided” AAs).
The combined total length of all nonbuffer
segments is less than 100 m for “2-
sided” AAs; 50 m for “1-sided” AAs.
OR
The combined total length of all nonbuffer
segments is between 100 m and 200
m for “2-sided” AAs; 50 m and 100 m for
“1-sided” AAs.
The combined total length of all nonbuffer
segments is between 100 m and 200
m for “2-sided” AAs; 50 m and 100 m for
“1-sided” AAs.
The combined total length of non-buffer
segments is greater than 200 m for “2-
sided” AAs; greater than 100 m for “1-
sided” AAs.
any condition
OR
For Distance of 500 m Downstream of
AA:
The combined total length of all non-buffer
segments is less than 100 m for wadeable
systems (“2-sided” AAs); 50 m for nonwadeable
systems (“1-sided” AAs).
The combined total length of all non-buffer
segments is between 100 m and 200 m for “2-
sided” AAs; 50 m and 100 m for “1-sided”
AAs.
The combined total length of all non-buffer
segments is less than 100 m for “2-sided”
AAs; is less than 50 m for “1-sided” AAs.
The combined total length of all non-buffer
segments is between 100 m and 200 m for “2-
sided” AAs; 50 m and 100 m for “1-sided”
AAs.
any condition
The combined total length of non-buffer
segments is greater than 200 m for “2-sided”
AAs; greater than 100 m for “1-sided” AAs.
4.1.2 Percent of AA with Buffer
A. Definition: The buffer is the area adjoining the AA that is in a natural or semi-natural state
and currently not dedicated to anthropogenic uses that would severely detract from its ability to
entrap contaminants, discourage visitation into the AA by people and non-native predators, or
otherwise protect the AA from stress and disturbance.
B. Rationale: The ability of buffers to protect a wetland increases with buffer extent along the
wetland perimeter. For some kinds of stress, such as predation by feral pets or disruption of
plant communities by cattle, small breaks in buffers may be adequate to nullify the benefits of an
existing buffer. However, for most stressors, small breaks in buffers caused by such features as
trails and small, unpaved roadways probably do not significantly disrupt the buffer functions.
C. Seasonality: This metric is not sensitive to seasonality.
D. Office and Field Indicators: The assessment should be conducted first in the office, using
aerial imagery and land-use maps, as available. The office work should then be verified in the
field. This metric is assessed by visually estimating the total percentage of the perimeter of the
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