An environmental watering program has been underway at the Chowilla Floodplain Icon Site since 2004. It has involved the delivery of environmental water by pumping or gravity feeding to 29 wetland sites across the floodplain. Many of these sites have been watered on two or more occasions.
This environmental watering through the millennium drought provided lifesaving water to long-lived vegetation including majestic old river red gums and black box trees, enabled the regeneration and growth of understorey plants including lignum, and provided refuge for many plant and animal species including vulnerable species such as the Southern bell frog.
In 2014 the construction of the Chowilla Creek environmental regulator and associated infrastructure was completed. These works enable water levels in the anabranch creeks to be raised so that large areas of the Chowilla Floodplain can be inundated when flows in the River Murray would otherwise be insufficient to do so. Full height operation of the environmental regulator enables the inundation of up to almost half of the floodplain, depending on the prevailing River Murray flow.
The environmental regulator and associated infrastructure has been successfully tested at low, medium and high levels of operation in conjunction with weir raising at Lock 6. These initial operations shows the great potential for floodplain recovery, however with each event there is still a lot to learn about how to maximise ecological benefits while ensuring risks are managed. The long-term aim is to restore the floodplain to a healthy condition so it is able to withstand the pressures of future droughts.
Small scale watering (pumping water to wetland and areas of the floodplain) may still be required during periods of extended low flows in the River Murray.
A program of condition monitoring including: trees, understory vegetation, birds, fish, and groundwater levels across the Chowilla Floodplain has been ongoing for a number of years. The extensive data from these monitoring programs provide important information which guides the environmental watering program, and supports the implementation of the Operation Plan for the Chowilla regulator and associated infrastructure.
Intervention monitoring projects are also undertaken to ensure that we can learn from management actions such as environmental watering to maximise the benefits and to enable us to manage any risks around the operation of the regulator and other infrastructure. This includes close monitoring of water flows and water quality and monitoring of native fish and habitat conditions in the Chowilla anabranch system.