Lake Cargelligo was originally a natural lake and wetland system, which supported large waterbird and native fish populations. In 1902, the NSW government built a weir and regulator to channel water from the Lachlan River into Lake Cargelligo for storage purposes. As Lake Cargelligo is downstream of all major tributaries, the operation of filling and releasing water from this storage has a significant impact on flow and water users in the lower Lachlan River.
Lake Cargelligo has been selected as a regionally significant wetland as it plays an important ecological and hydrological role in riverine functions within the lower Lachlan. It functions as an important drought refuge as it is one of the few wetland systems to consistently receive water even under drought conditions due to the need to supply town water. Its value as a drought refuge is also supported by the dead storage volume of around 6,000 ML, retaining water for significant periods during drought. It is also a wetland of outstanding historical and cultural significance as it is an important centre for both Aboriginal and non-Aboriginal communities.
To improve the quality of the wetland systems as a drought refuge the Lake Cargelligo Environmental Management Plan is being developed by the Lake Cargelligo community.
As this system is serviced by the Lake Cargelligo Weir and associated inlet channels, commence to flow details have not been included.