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Croppers Lagoon is situated on the northern side of the Murray River floodplain about 5 km downstream from Corowa New South Wales (NSW). It is one of many similar lagoons located on both sides of the river between Hume Dam and Yarrawonga Weir. The Lagoon receives water from the river by a narrow inlet/outlet creek except during very low flows.
A number of studies of the hydrology and ecology of the Lagoon have been conducted. Results of these studies indicate that the damming and regulation of the Murray River have radically altered the hydrology of the Lagoon, which in turn has impacted upon flora and fauna associated with the wetland. During pre-regulation conditions the Lagoon would have received higher or flood flows in winter months and experienced lower water levels during summer months. However due to river regulation this pattern has been reversed - causing higher flows to enter the Lagoon during the summer months and lower water levels occurring in the winter.
The draw down of the lagoon helps vegetation species
to re-establish. Photo courtesy of Deb Nias
To rehabilitate the wetland manipulation of the Lagoon's hydrology was required, with the aim to more closely reflect the natural hydrological variations. The construction of a regulator at the main inlet/outlet channel, which is also the major connection to the river helped to re-establish a more natural hydrological pattern and therefore also many of the original ecological processes within the wetland. The regulator is used by managers to prevent high summer flows from inundating the Lagoon.
The construction of a regulator to help create a natural
wetting/drying phase. Photo courtesy of Deb Nias
Since the return of a more natural hydrology the native vegetation communities have improved,including regeneration of River Red Gums Eucalyptus camaldulensis, and the emergence of aquatic species such as Milfoils Myriophyllum spp., Pondweeds Potamogeton spp., Eel grass (Vallisneria spp.), and the Giant Rush (Juncus ingens).
The re-establishment of various vegetation species after drying phase in Croppers Lagoon has occurred
after many years of unnatural flows. Photo courtesy of Deb Nias
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