2.2 | Rapid assessment procedure
The stability and function of instream structures was evaluated using a
rapid assessment procedure developed by Miller & Kochel (2013).
Assessments were conducted annually from 2014-2018 and in 2020.
Structures (n = 137) were grouped into the following types: boulder
cluster, boulder toe, boulder vane, cobble toe, grade control (main
channel or side channel), log toe, and log vane. Descriptions for each
structure type, including anticipated functions, and sample sizes were
presented in Table 1. Typical photos for all structure types, detailed
maps of the project reach, and repeat photographs for each structure
were included with the Supporting Information. Rapid assessment surveys
were conducted after snowmelt runoff each year, sometime during
August-November, to evaluate each structure for integrity and function,
as well as unintended erosion and deposition, using the rankings
presented in Table 2. To evaluate structural integrity and function,
rankings of intact (1) and damaged (2) were considered stable and
functional, while rankings of impaired (3) and failed (4) indicated that
the structure no longer functioned and were counted against the 90%
objective for integrity. For erosion and deposition, performance
rankings ≥ 3 were considered non-functional. Due to a relatively high
number of failures, log-vane structures were analyzed separately to
determine if improper design or construction contributed to the
failures. Specifications for log vanes included an angle of departure =
20-30° and slope = 2-7% (Rosgen, 2006). The angle of departure and
slope for each log vane were calculated from the as-built survey and
used for the post hoc analysis of log vane performance. Some
structures were removed during maintenance in 2016, after which they
were excluded from the survey in subsequent years, as were any
structures that had failed in the preceding year.