Yambuk Lake is located adjacent to Yambuk township and is the estuary of the Eumeralla and Shaw Rivers. It includes the Yambuk wetlands.

The estuary is a seasonally closed, estuarine coastal lagoon system and is formed in a drowned river valley.  Water quality varies through the year depending on flow and entrance conditions. The estuary is termed a salt wedge estuary due to the presence of a deep saltwater layer and shallow freshwater layer for much of the year. The floor of the estuary is mostly mud with a sandy area at the mouth.

The Yambuk estuary and wetlands are habitat for many species. Sixty-nine indigenous flora species and over 140 bird species have been recorded in the area including important migratory species and some listed under the Victorian Flora and Fauna Guarantee Act, 1988. Critically endangered species include the orange-bellied parrot and little egret.

Twenty-four fish species are known to inhabit the estuary and wetlands, including dwarf galaxias and Yarra pygmy perch. Both species are listed under the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999 (vulnerable and endangered respectively).

Yambuk Lake and its fringing wetlands are of national significance due to their habitat value and because the area is considered an excellent example of an estuary with fringing wetlands.