Developing a sediment trapping system
Project title: Developing a sediment trapping system in the Silkwood Drainage board area (SDBA)
Group Name: Silkwood Drainage Board
Objectives
- Develop best practice for controlling sediment flows within wet tropics sugar cane farm drainage systems
- Encourage all SDBA members to include sediment trapping in their farm drainage system
- Contribute to sustainability for sugar cane growing in the Great Barrier Reef catchment area (GBRCA).
- Work toward best practice concepts in grower group participative research
- Develop information sharing capacity
Project Activities:
The SDBA members will hold an open meeting with interested growers in Silkwood to discuss the project of designing and creating a system of sediment traps into a typical farm layout, in particular within the SDBA. This first meeting is important to get the collaboration and support of the members of the drainage board. The strategies to achieve this are;
1. Letters will be sent to members introducing the project proposal and open meeting
2. There will be emphasis on the farmers environmental obligation to reduce soil losses off farm, it is better to be seen to be doing something than to be told to do it.
3. Explain that once these systems are in place members will actually appreciate a reduced overall cost through a change in the drain maintenance program. This is because instead of soil runoff being distributed throughout the drain system and further it will be contained at specific sites. Therefore it will not be necessary to strip the drain floors every year or so to remove silt. This is a process which leaves headlands mounded up with grass and dirt and is difficult for the farmer to remove.
4. It will be explained that it is important for farmers to support the project so that SRDC will provide funding to establish the proposed sediment trapping system.
Farmers will be asked to make available their farm sites for both sediment trap construction and the monitoring of control sites. The meeting will then form a project team to manage the process. The team will seek information on sediment trapping design models which could be applied to a cane farm situation. There are difficulties in designing a system that will adequately control sediment movement off site given a variety of weather conditions and events, type and extent of the soil cultivation, and variations of each site. Therefore it will be necessary to travel to particular areas where these systems are working successfully. A literature search and inter industry exchange of information should aid in system design. The design concept will then be applied to a number of Silkwood farm trial sites within the SDBA. Control sites will be used to compare and contrast soil erosion and nutrient runoff against the sediment trap demonstration areas. It is anticipated to develop nine sediment traps into the SDBA. These are to be strategically positioned to achieve a high sediment collection outcome.
Contact person: Ian Brooks 4065 2346 farmlets@internode.on.net
Photos of different designs of sediment traps