Kerri Goschnick, land management extension officer
Maintenance is the key to reducing soil and sediment movement in paddocks. While spring rain is valuable for pastures and replenishing farm dams, run-off may also carry sediment into livestock dams, particularly where there is exposed soil in heavily grazed paddocks.
Hay bales or netting held together with steel posts or stakes to control sediment flow into dams can be a good starting point, although the cost of hay and the hazard of steel posts should be considered. Coir logs are a potential alternative to hay bales.
Fibreglass posts and construction site hazard fencing (barrier mesh) are another, often safer option. Using 20 m of barrier mesh and 4 fibreglass posts upstream of a dam is both highly visible and relatively low cost, at around $85 per site.
Aim for mesh openings that are no smaller than 100 mm square. Smaller openings will block up with debris too quickly and the fence will fail. It is also important to remove stakes or mesh once the risk of sedimentation has reduced, to avoid debris build up.
Building earthen banks to protect areas from sedimentation usually requires survey design, knowledge of soil type and risks, and suitable equipment and expertise to successfully construct. A good understanding of catchment size and potential water volumes is necessary to avoid failure.
Road and track maintenance is also important. Annual maintenance, with a slight camber in the road surface to shed water to the side with the shortest distance possible, will help to prevent wheel tracks from developing into drains and washing out the track surface.
Culverts and side drains should also be cleaned annually to prevent blockages and water from being redirected to less suitable discharge areas.
Visit the Agriculture Victoria website for articles on soil retention and sediment movement on agricultural land following drought, fire, strong winds and rainfall events.
Grants of up to $5,000 are available for farmers to support investment in on-farm drought management activities and be better prepared for future droughts.
Eligible activities include water infrastructure upgrades such as pipes, tanks, troughs and dams, stock containment areas, grain and fodder storage, water carting and pasture re-establishment.
Visit www.ruralfinance.com.au/grants/ to apply.
