Soil Compaction and Waste Materials cut Water Losses from On-Farm Channels
Summary
This project describes a holistic approach for assessing seepage losses from supply systems, one which aims to provide an evaluation of alternative high-tech and low cost technologies for reducing conveyance losses from irrigation systems overlying different subsoil conditions. Relative costs of alternative cost-saving options were worked out to help determine the investment efficiency of reducing losses by sealing sections of leaky channels using material lining, and machine compaction.
Objectives
The major objective of the project will be to evaluate techniques to reduce water seepage losses from channels and drains which would reduce adverse environmental impacts and increase distribution efficiency of on-farm channels and drains.
Outcomes
1. An assessment of the effect of compaction and lining materials on the seepage rate in existing on-farm channel and drainage networks.
2. Identification of appropriate compaction or lining technologies to allow improved channel distribution efficiency.
3. Economic evaluation of the benefits of these technologies to the farmers and the community.
4. A Decision Support System (DSS) developed to guide grower actions in response to seepage from channels and drains.
5. Development of two and three dimensional channel and drain ground water interaction models
Methodology
Seepage minimisation treatments will involve high-energy compaction and clay lining work on the channel or drain banks; bed; or on both the bed and banks. The sites chosen have been identified as high seepage rate sites for seepage remediation work.
In this study, two methods of controlling seepage, clay lining and compaction will be assessed on at least four farms in the first year of the project and monitoring on these farms will continue for the second and third year. On each farm four sites for compaction work and one site for lining will be selected.
The soil compaction/lining will be applied in the predetermined sites in farm channels and drains to assess the impacts of various levels of compaction and lining. Seepage monitoring will continue for three years to examine the longevity and efficiency of sealing treatment over time.
Good engineering practice would be adequate to minimise seepage and leakage from on-farm channels and drains. After reviewing the performance of different compaction machinery, Impactor roller seems to be appropriate and suitable for channel compaction.
The decision to conduct an EM survey to confirm sections of farm channels, which appear to be leaking, may be made on the basis of observations of channel/water behaviour by the operator of the channel and visual indicators. There is always the possibility that the owner of the channel is aware of the extent of leakage and considers the cost of remedial action unjustified.
Funding agencies
- NSW Department of Primary Industries
- Cooperative Research Centre for Sustainable Rice Production
Leader
Saud Akbar
Richmond (Hawkesbury)
News: Saud was a co-winner of the 2007 Eureka Prize for Water Research and Innovation