A water budget takes into account evaporation from storages, seepage, other animal usage and fouling to then allow assessment of amounts of water available for stock to drink.
The availability of stock water over summer is becoming a critical issue in some areas of the NSW South East region.
Knowing where water is on farm and how much is available is vital in times of drought.
In fact for producers, a water budget is just as important as a feed budget.
History has shown that it is not a feasible practice to be carting water to livestock for extended periods.
Fiona Leech, senior agriculture advisor with South East Local Land Services is advising producers to think about their water needs now.
“Evaporation rates over the summer period can result in the loss of between 1 m and 1.5 m depth of water from dams, so an on-farm water budget is a useful tool to identify issues around possible water shortages for livestock over the months ahead.” Fiona said.
“Those with past experience on a given farm are likely to have a good knowledge of water storages present including their capacity and ability to hold water as we move into drier times.
“However, it is a recommendation to all regardless of your experience with current on-farm water storages, to assess your situation without delay as we move into the heat of summer.”
A water budget takes into account evaporation from storages, seepage, other animal usage and fouling to then allow assessment of amounts of water available for stock to drink. A calculation using numbers of animals and their predicted water intake will then allow you to determine a timeframe for which the water will last.
As on-farm water storages move to more critical levels there are things that can be done to help conserve the water.
“It is always advisable to first graze paddocks with diminishing water supply.
“Shifting and consolidating water is a useful way to help reduce evaporation losses and also provides an opportunity for shallower dams to be cleaned out.”
Troughing water out of dams is a means to achieving better extraction of the water and reducing the risk of stock getting stuck as the dams lower. Troughing water via the use of a header tank is also worth considering in order to reduce evaporation of the limited water supply.
In more recent years evaporation rates have exceeded past records due to warmer temperatures and increased wind events. Dams with more protection from vegetation will help reduce evaporation rates.
“In assessing your water situation on farm it is important to also remember that rainfall events over summer are erratic and there is always a chance that heavy thunderstorm activity may provide run-off water into dams ultimately providing some relief to water shortage issues.
“Unfortunately such run-off from heavy rain can bring debris, manure etc. with it often fouling the dam water collected in the short term.”
-Local Land Services