Water users will start to notice a change to the River Murray water levels during July as weir pool raising commences to improve the health of the river and environment.
Raising of the weir pool upstream of Lock 2 will help restore a more natural wetting cycle and reconnect the main river channel with the nearby floodplains and wetlands to benefit the growth and breeding of local wildlife.
Water levels will be raised up to 55 centimetres above normal level in the Lock 2 weir pool. The raising will use water for the environment that is currently flowing into the Lower Murray region from upstream watering actions.
Department for Environment and Water (DEW) Water Delivery Manager, Chrissie Bloss said the whole of the River Murray system is highly regulated and the use of water regulating infrastructure to achieve environmental outcomes is becoming an increasing feature of river operations.
“The lock and weir structures were built more than a hundred years ago to manually alter water levels along the River Murray for irrigators, but stable water levels favour introduced species like carp and do not provide suitable conditions for many native fish and other animals and birds to breed, feed and survive,” Ms Bloss said.
“Weir pool raising improves vegetation and macroinvertebrate communities by spreading plant seeds and supporting the creation of food sources for bugs and fish.
“By increasing water levels upstream of the weir it also provides a drink to surrounding low-level wetland and floodplain areas.
“Weir pool raising uses water for the environment to raise the weir pools to a specified level, which is particularly important during dry times, when just like other water uses, the environment receives lower allocations.
“Setting water aside for the environment during all years ensures that our working river survives drier times.
Water levels will return to the normal pool level of 6.1 metres by mid November 2021.
Weir pool raising is a collaborative action between the Department for Environment and Water and SA Water, with water supplied by the Commonwealth Environmental Water Holder.
For further information on weir pool manipulation visit the DEW website.