Water for the environment at the Chowilla, Pike and Katarapko floodplains in South Australia has delivered key ecological outcomes for the area.
From August to late November 2021, the floodplain regulators at Chowilla, Pike and Katarapko were operated concurrently for the first time, along with weir pool raising at Locks 6, 5, 4 and 2.
Floodplain regulators allow river operators to manage water level and flow into the floodplains, complementing natural wetting and drying cycles within floodplains, wetlands and creeks. Although these types of flows cannot fully replace the benefits of a natural flood, they are water efficient and help sustain native species within these ecosystems.
The watering event raised levels by 3.2 metres within the floodplain creeks, which along with the Lock 4 weir raising, delivered water across more than 1,100 hectares of floodplain during spring 2021.
Positive ecological outcomes include:
- floodplain trees and other vegetation responding with new growth
- an increased habitat for native wildlife
- thousands of waterbirds, comprising 44 species were recorded at Chowilla
- eight frog species, including the southern bell frog, were recorded at Chowilla and confirmed to be breeding.
Data collected from this water for the environment event will be used to inform planning for floodplain operations in 2022.
The water used was provided by the Commonwealth Environmental Water Holder and the Murray–Darling Basin Authority’s The Living Murray program, as well as by the river flows from upstream rainfall. The environmental infrastructure at Pike and Katarapko were delivered through the South Australian Riverland Floodplains Integrated Infrastructure Program, a $155 million investment program funded by the Australian Government and implemented by the South Australian Government to improve the watering and management of River Murray floodplains in the Riverland.
The Chowilla infrastructure was delivered through the Living Murray, a joint initiative funded by the New South Wales, Victorian, South Australian, Australian Capital Territory and Commonwealth governments and coordinated by the Murray–Darling Basin Authority.