At 70 kilometres long, the Tamar is one of the longest estuaries in Australia. The catchment that feeds the estuary is around 10,000km² fed by key tributaries including the North Esk, South Esk, Macquarie, Meander, Brumbys and Lake rivers.

The area encompasses a number of uses such as grazing, dairying, forestry, mining, residential and industrial activities and what happens as far away as Tunbridge, Fingal and Deloraine can impact on the estuary’s health at Launceston or George Town.