Water quality is of major concern to our ongoing operation on Mundoo Island station as livestock require good quality, fresh water for their survival - as do the many native wetland species.
Due to our proximity to the salt water of the Coorong and the leaking barrage structures we are constantly faced with the possibility of salt water incursions into the fresh water of the River Murray, thus resulting in pumping saline water throughout our water reticulation set-up. Other sources of salt water incursion is from the recently installed fish passage-ways in the barrages and salt water storms that over-top the barrage gates.
The Millennium Drought caused great distress as we initially unknowingly pumped salt water to our cattle. We were unaware that the salt water was leaking under the barrage gates and polluting the fresh water supply we relied on.
We spent hours searching for limestone rocky outcrops to excavate so that we could provide freshwater soaks for the cattle on our islands. The lens of freshwater in each soak may last a day or a week, we did not know. We initially cleaned the original historic freshwater soaks on Mundoo Island that were used pre-barrages for stock water but found that they were saltier than the sea. We realised some channels that passed through limestone rocky reefs contained fresh water lenses which provided drinking water for our stock and healthy water for the native fish species refuges.
The ongoing search for pockets of fresh water was vital to our cattle’s survival. We regularly tested the water available with a salinity tester to measure the EC (electrical conductivity estimates the amount of dissolved salts in water for salinity tests) of the water. Beef cattle can sustain healthy growth with salinity levels of up to 7,140 EC (ɲ S/cm) and can maintain condition at 8,925 EC. Once salinity levels go above this point, beef cattle cannot maintain condition and suffer poor health - often resulting in death.
We recorded salinity readings of up to 48,000 EC – nearly as salty as sea water (approximately 50,000 EC). It is no wonder our stock were dying.,
Hence we keep a close eye on salinity readings in our waterways now. This is to ensure water integrity for our livestock and the many native species in our wetlands that rely on the fresh water environment for their survival.