Yarradda Lagoon, west of Darlington Point, is an important colonial waterbird breeding site on the Murrumbidgee River, but was hit hard by the millennium drought. In recent months, neighbouring landholders have managed the delivery of environmental water to the lagoon, on behalf of the NSW Office of Environment and Heritage (OEH) and the Commonwealth Environmental Water Holder. A total of 1150 megalitres of environmental water was pumped into the lagoon which is listed on the Directory of Important Wetlands Australia (DIWA) because of its significance in providing habitat for colonial nesting birds and migratory bird species.
Senior Environmental Water Manager James Maguire said the project would help to restore the long term health of the lagoon:
At just over three metres deep, Yarradda Lagoon often retains water during dry periods making it a sanctuary for native fish, frogs and a range of plant and animal species. It’s part of a network of wetlands, which progressively become connected to a rising river after periods of significant rainfall or environmental flow releases. During those times of connection, the wetlands provide ideal habitat for native fish spawning and feeding, then for months or years afterwards they provide habitat for waterbirds, frogs, turtles and other fauna.
Like many other Murrumbidgee sites, the aquatic vegetation in Yarradda Lagoon has not recovered from the drought and the pumping of environmental water is primarily aimed at re-establishing the rushes, lilies and native grasses. To monitor ecological responses to environmental water, the lagoon has been selected for inclusion in a five year monitoring project, funded by the Commonwealth Environmental Water Holder and implemented by Charles Sturt University. James Maguire said that
Already researchers have found a few small patches of the native aquatic grasses which once fringed the lagoon along with abundant tadpoles and just one species of fish: the native bony bream. While pumping isn’t our preferred option for watering wetlands, it does mean there are no carp, which will aid in the re-establishment of the aquatic plants, frog breeding and water quality.
The watering of Yarradda Lagoon was overseen by neighbouring landholders Lawry and Liz Owers of ‘North Kerarbury’ who own the pump and irrigation channel which delivered the environmental water to the lagoon. Commonwealth Environmental Water Holder David Papps acknowledged the contribution of the Owers’ along with the work of Office of Environment and Heritage and Riverina Local Land Services staff.
Local knowledge is critical to the success of environmental water management and we would encourage other local landholders to get in touch with Office of Environment and Heritage or Local Land Services staff to get involved in future watering activities. Mr Papps said.
The Yarradda Lagoon project was co-funded by the Riverina Local Land Services with environmental water supplied by the Commonwealth Environmental Water Holder.
The rivers and wetlands of the Murrumbidgee is now the focus of monitoring and evaluation work being undertaken by Charles Sturt University as part of the Commonwealth Environmental Water Holder’s new $30 million Long Term Intervention Monitoring Project designed to provide all Murray Darling water managers with greater insights and knowledge into the effectiveness of environmental watering.