The Gudgenby River is a river in the Australian Capital Territory

Australian Capital Territory

The Australian Capital Territory, often abbreviated ACT, is the capital territory of the Commonwealth of Australia and is the smallest self-governing internal territory...

 that flows predominantly through the forests of the Namadgi National Park

Namadgi National Park

Namadgi National Park is located in the southwestern part of the Australian Capital Territory, bordering Kosciuszko National Park in New South Wales. It lies approximately 40 km southwest of Canberra, and makes up approximately 46% of the ACT's land area....

. The river catchment contains ecologically significant alpine wetlands. It flows into the Murrumbidgee River

Murrumbidgee River

The Murrumbidgee River is a major river in the state of New South Wales, Australia, and the Australian Capital Territory . A major tributary of the Murray River, the Murrumbidgee flows in a west-northwesterly direction from the foot of Peppercorn Hill in the Fiery Range of the Snowy Mountains,...

 immediately upstream of Tharwa village and to the south of Canberra

Canberra

Canberra is the capital city of Australia. With a population of over 345,000, it is Australia's largest inland city and the eighth-largest city overall. The city is located at the northern end of the Australian Capital Territory , south-west of Sydney, and north-east of Melbourne...

.

The Gudgenby has been investigated as a site for a new dam to provide water to the ACT. Two dams have been proposed for construction near Mount Tennent

Mount Tennent

Mount Tennent is a mountain in the southern part of the Australian Capital Territory. At the base of the mountain flows the Gudgenby River and this is a site for the proposed Mount Tennent Dam....

, a small dam with a capacity of approximately 43 GL or a large 159 GL capacity dam which would more than double water storage capacity in the ACT.