Water for the Pike Floodplain
The specific ecological objectives for environmental watering at the Pike Floodplain are to:
- improve the condition of long-lived native vegetation that provides important habitat, including river red gum, black box and lignum, and ensure their populations are sustained by encouraging the establishment of new age classes
- provide opportunities for short-lived amphibious and flood-responding understorey plants to germinate and complete their life cycle, enabling them to maintain their seedbank in preparation for the next flood or watering operation
- enable exchange of nutrients between aquatic and terrestrial ecosystems to fuel the food web and encourage a diversity of water bugs to feed fish, frogs, bats, birds and other floodplain fauna
- increase the extent of temporary wetland habitat available for waterbird, frog, turtle and small-bodied native fish breeding and foraging.
How water delivery works
Floodplain infrastructure
Floodplain infrastructure is used to deliver of water for the environment and increase water levels through the anabranch creeks to inundate large areas of the floodplain.
Floodplain infrastructure includes:
- two major environmental regulators (the Pike and Tanyaca regulators)
- a series of smaller ancillary regulators
- blocking banks
- fishways (to allow fish to move through the regulators in the floodplain anabranches).
In addition, groundwater infrastructure manages groundwater levels to help control the amount of salt entering floodplain anabranch creeks.
These structures were built through the Riverine Recovery Project and the SA Riverland Floodplain Integrated Infrastructure Program.
How it works
Floodplain infrastructure is operated to raise water levels in the floodplain creeks enabling water to spread across areas of the floodplain that would otherwise be dry during lower River Murray flows.
Water flows into the Pike anabranch system, through 2 inlet creeks located above Lock 5. During a watering operation water levels are raised behind the floodplain regulators which then pushes water into flow path sand over banks into wetlands and across the floodplain. There are continuous flows maintained over the regulators with flows connecting back into the River Murray downstream of Lock 5.. The raised water levels are maintained for a planned amount of time before being lowered back to the normal operating levels. Lock 5 is also raised in conjunction with larger scale raising of the floodplain regulators to help to maintain good flows through the anabranch creeks.
Operating the regulators
Managed watering events are planned to target a particular height of regulator operation at Pike. The regulators can be operated over a range of up to 1.85 metres above the anabranches’ usual pool level.
The effects of floodplain watering vary depending on the level of inundation we aim for.
| Level of operation | Action |
|---|---|
| Low level managed inundation | Raise water levels in the permanent anabranches, creeks and wetlands. Low levels of managed inundation can be undertaken without concurrent operation of Weir 5. |
| Medium level managed inundation | Water extends to inundate low-lying temporary wetlands and shedding floodplain. At medium and high levels operations, Weir 5 is also raised to assist water flow through the floodplain anabranches to protect water quality. |
| High level managed inundation | Generates larger scale watering of wetlands, including reaching temporary wetlands at higher elevations and a larger area of shedding floodplain. |
Timing
Planning for the delivery of water for the environment to Pike Floodplain occurs each year, in-line with the SA River Murray annual environmental watering plan and priorities (find it here).
The decision to water is made based on floodplain conditions and flow outlook, so watering is not undertaken every year. When delivery is planned, watering most often occurs between mid to late winter through to early summer.
An extensive suite of modelling tools is used to assess potential risks to water quality and estimate the volumes of water required to reach the target inundation level.
Access to the area
The majority of the Pike Floodplain is Crown Land and some areas are protected under the National Reserve System. Vehicles are not permitted on the Pike Floodplain, however, visitors can kayak and walk or ride on existing tracks.
Some short-term access restrictions may be put in place during medium level and high level environmental watering operations.
More information about access and restrictions is available at the Department for Environment and Water Office in Berri.
Does watering work?
Long-term scientific monitoring tracks the ecological condition of the floodplain in connection with the goals listed above. Monitoring also informs decision-making around how we manage delivery of water for the environment.
The monitoring program includes vegetation, fish, waterbirds, bushbirds, frogs, bats, soil, groundwater and water quality.
Highlights from 2023-2024 ecological monitoring
Plants
Black box tree condition improved. All river red gum trees met the tree condition targets. Tree seedlings and saplings continued to develop.
Stands of lignum and the understorey plant community were in good condition providing diverse food resources and habitat.
Frogs
All riparian frog species typically recorded at Pike floodplain were detected in Spring 2023.
Birds
38 species of waterbird were recorded from spring to autumn 2024. As the wetland water levels receded they provided productive foraging mudflats for many of these bird species.
A number of rare species such as the great crested grebe, Australasian shovelers, and musk ducks were observed. Australian shelduck, yellowbilled spoonbill and black-fronted dotterel were also observed breeding during spring.
Wedge-tailed eagles, grey butcherbirds, and dusky woodswallows adults nesting or with dependent young were also observed.
Fish
2,960 fish were captured from 11 species (8 native and 3 non-native) during the annual condition monitoring in autumn.
The most abundant native species was bony herring and the most abundant non-native species was common carp.
The Murray cod (listed as vulnerable and freshwater catfish (a protected species in SA) were also sampled.
High flows in the Pike Floodplain 2016
How to stay informed
- Sign-up to receive the weekly River Murray Flow Report via email for information on when water levels will rise, expected water level depths and the expected duration. View previous reports
- Visit the National Parks and Wildlife Service SA website
- Find out how to get involved in environmental water planning by contacting us at dew.ewater@sa.gov.au
- Subscribe to our mailing list to receive updates on your chosen location and hear about opportunities to get involved
