With patchy rainfall across the state and the forecast of a drier spring, now is an ideal time to start monitoring dam water levels.
Over recent years, stock water has become a scarce commodity across many parts of Victoria, significantly impacting livestock carrying capacity over the drier months. Taking stock of dam water levels and pasture growth over the next few months will greatly assist farmers in calculating potential carrying capacity heading into summer.
With current low water levels, it is also an ideal time to set up a permanent water level marker in larger storages.
A simple depth pole can be made using a length of PVC pipe slipped over a long, heavy-duty, galvanised steel post. Marking the pipe with 10-centimetre-wide strips of red paint, spaced 10 centimetres apart, makes monitoring straightforward. Making a reading simply involves counting the number of strips visible from the top of the pole down to the water level.
Taking a date-stamped photograph is an easy way to record and store these tracking results over time.
It is important to remember that the rate of a water level rise will slow as the dam approaches full supply level. This is because larger volumes of water are required to fill the wider, upper levels of a dam structure. In a typical three-metre-deep farm dam, 60 per cent of its total volume is contained within the top one metre.
Knowing the depth and dimensions of water in a dam allows farmers to quickly calculate its remaining volume using the Farm Water Calculator. This simple digital tool is available on the Agriculture Victoria website.
Dam runoff in Victoria usually commences in late winter and ends in late spring. While thunderstorms can fill a dam at any time of the year, relying on significant runoff after this period is a risky strategy for stock security.
By Clem Sturmfels, Land Management Extension Officer
