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| 5 Implement seepage measurement techniques |
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Purpose
To undertake seepage tests on-site and document the distribution
and rate of seepage from the channel.
Inputs
Information about preferred techniques, including specifications
and operational and other constraints.
Description
- Develop a work plan for the technique selected
- Set up contracts
and engage contractors to undertake the works (if required)
- Undertake
the tests and collate test data
- Undertake calculations for quantification
and determine seepage mechanisms
- Extrapolate test information
to entire area of interest (where appropriate)
- Report on the
results, perhaps including preparation of maps displaying distributions
of seepage zones, profiles of seepage
impacts, etc.
| Responsibility/decision
makers |
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Contractors, project officers, project engineers
| Output |
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Outputs that can be obtained include:
- Estimates of seepage rates
- Maps showing the distribution of
seepage zones
- Report on the work undertaken, including test
results
Local-scale recommendations
[Up to approximately 400m in length] |
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The techniques recommended for local-scale investigations are
outlined in 4 Selection of seepage measurement
techniques.
Techniques appropriate for local investigations
depend on whether there is a need for:
- Measurement of seepage rates at specific locations;
or
- Identification of higher permeability zones within a section
and measurement and mapping of seeping variability.
Specific locations
For measurement of seepage
rates at specific locations, the techniques that should
be considered are:
Mapping seepage variability
To map seepage variability
on a local scale, the recommended approach is similar to that for
intermediate to large-scale investigations. However, for local-scale
investigations point measurement and groundwater
assessment could be used in addition
to pondage tests.
Intermediate to large-scale recommendations
[Hundreds of metres to tens of kilometres
in length] |
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The techniques recommended for intermediate to
large scale investigations
are outlined in 5a Intermediate
to large scale: recommended implementation approach.
The approach includes the
following elements:
- Map spatial variability in geophysical response
- Basic seepage
quantification
- Relationship between seepage and geophysical
response
- Interpretation and extrapolation of results beyond
the test sections
- Extrapolation of seepage measurements
- Extrapolation of geophysical
data
- Extrapolation of soil and geological information
| Related
pages |
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Previous: 4 Select
seepage measurement techniques
Next: 5a Intermediate
to
large scale: recommended implementation approach |
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