|
|
||
 Monitoring and Maintenance of Stabilization Works
Displacement or separation of armor material which exposes erodible bank
material. Such displacement can be due to hydraulic forces, to geotechnical
factors such as slope settlement or piping, or to vegetative disruption.
Gradual deterioration of mattress elements or retard and dike components.
Condition of planted and volunteer vegetation.
11.2.7 LEVELS OF MONITORING EFFORTS
11.2.7.1 Level 1 Monitoring
Level 1 monitoring effort consists of a field reconnaissance and visual observation of
the site, and a written report detailing the present conditions found at the site. This written
report can also include a comparison between the present existing conditions and previous
findings recorded during other site visits or supplemental data from aerial photographs or
other sources and analysis of future stream movement and behavior (down valley migration,
degradation, etc.). If an existing streambank protection project is within the study reach, an
analysis of the performance of this project can also be included in this report.
11.2.7.2 Level 2 Monitoring
Level 2 monitoring effort consists of all activities performed during a Level 1
monitoring effort plus a permanent photographic and/or videotape record of the project area.
Photos should be shot from fixed and marked locations so that comparisons can be made over
time. All photos should be indexed and accompanied by well written descriptions of the
contents of the photographs plus the location where the photo was shot.
11.2.7.3 Level 3 Monitoring
Level 3 monitoring effort consists of all activities performed during a Level 2
monitoring effort plus some physical measurements of the site (possibly using the typical low-
flow water surface elevation as a datum). These measurements would typically be limited to
delineation and locations of active scour areas, maximum scour depths in the stream, and
scour depths near or at the toe of existing protection works.
11.2.7.4 Level 4 Monitoring
A Level 4 monitoring consists of all activities associated with a Level 3 monitoring
effort plus a comprehensive survey of the reach of stream in the immediate area of the
protection works. This survey can also include a less intensive survey of the general planform
242
2 2
|
||
|
||
