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Introduction
This website provides practical information and tools to assist Australian
rural water authorities in managing irrigation channel seepage.
The home page and left-hand menu of all other pages links to six
key sections, or steps in the seepage management process:
You can work through the site step-by-step, or go straight to a
particular topic. If you go straight to a particular topic, ensure
that you
are aware of all steps, because the order of the steps is important
in achieving a positive outcome. You may need to go back and revisit
steps as the site is updated.
There are links from all pages to:
Case studies
Downloads
Contact us
Glossary
References
Site map
Each of these items is summarised below.
Six key steps in seepage
management
Seepage Risk Potential
Seepage from open channels, mostly constructed using local
materials, is an Australia-wide problem. Seepage rates vary
depending on local
conditions, and a summary of examples from literature is
presented. Known or suspected seepage is inspected and tested,
and flow
records considered. A risk management framework can be used.
Reasons for
investigation include water loss concerns, local land degradation
and environmental concerns, and regional environmental concerns.
Methods used to assess seepage risk are discussed.
Identification and measurement
How to identify and quantify seepage
A key step in managing channel seepage is identifying the
location and measuring the rate of seepage. Issues include
physical
conditions; soil, hydraulic and channel water characteristics;
seepage mechanisms
(horizontal and vertic22/10/07 to large and macro). Seepage identification and measurement
techniques
are
described in terms of principle, method, applicability, practical
implementation, experience and indicative costs. Steps in
planning, implementation and evaluation are: define objectives,
collate
site data, evaluate data, select techniques, implement techniques,
evaluate
results.
Remediation
How to reduce channel seepage
Channel seepage remediation involves the assessment of available
techniques based on site conditions, objectives, economic
analysis and consideration of all options. Remediation works
require
a maintenance program and ongoing monitoring of effectiveness.
Remediation costs, benefits
How much will it cost to do nothing or fix it? Is it worth
it? Economic evaluation cost/benefit analysis.
Cost-benefit analysis is used to evaluate techniques for
a specific site. Information should be reviewed by experienced
personnel.
The objective is selection of sites and techniques that maximises
the
overall net present value within the capital budget available.
Prioritisation of works
What is the preferred method for each site? In what order
should works be undertaken?
Multi-criteria analysis may be necessary in addition to cost-benefit
analysis to enable seepage remediation works to be prioritised.
The Decision Support Tool may be downloaded to assist with
the evaluation.
Project review
Have we fixed the problem? How effective was the approach?
Monitoring the effectiveness of seepage remediation techniques
is essential, both to confirm the seepage reduction achieved
initially, and to assess ongoing performance. Groundwater
levels should be
monitored
to indicate success. Feedback is invited and links are provided
to two case studies from the IAL trials.
How to access key steps
Each of the sections relating to the key steps can be accessed
in a number of ways, either via the home page or the navigation
buttons
in the main menu on the left-hand side of each page or the
site map or by searching.
Other information
Case studies
Includes case studies of the Donald Main Channel and Waranga Western
Channel. Also provides instructions on how to download the Case
study template and submit additional case studies to the relevant
IAL contact.
Downloads
A number of documents and tools can be downloaded from the home
page or the Downloads link in the menu on the left-hand side of
each internal page, including the following:
- Best practice guidelines for channel seepage identification
and measurement
- Guidelines for channel seepage remediation
- Pondage test analysis
tool
- Channel seepage decision support tool, including cost calculator,
cost benefit analysis and multi-criteria analysis
- Case study
template
Contact us
Contact details for IAL and an email facility for suggestions
and queries regarding this website.
Glossary
Glossary of terms related to irrigation channel seepage.
References
Bibliography relevant to irrigation channel seepage reduction and
the IAL trials that underpin the information on this website.
Site map
List of links to key pages on the site – like a table of
contents for the website
Browser version
This website works best with the browsers listed below. Click on
the links to download.
Internet Explorer 5+
Netscape 6+
Safari 1+ (Mac
only)
Print settings
To ensure that web pages print correctly, please go to Page Setup (under
your browsers File menu) and set your margins (left and right) to 5mm,
or the minimum default for your printer.
For best printing results, also ensure that 'Print background
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