Gullies that start on the steep banks of rivers and cut into terraces or elevated floodplains (alluvial gullies) are a major factor affecting the water quality of the Great Barrier Reef. Griffith University’s Associate Professor Andrew Brooks is leading a NESP Tropical Water Quality Hub project to test the effectiveness of different techniques used for rehabilitating these large alluvial gullies. Working with Cape York NRM, Greening Australia and the Queensland Government, they are trialing a variety of methods including earthworks, gypsum application, mulching, rock capping, and revegetation to reduce the sediment delivered from highly active gullies. To see some of these techniques in action, this video of rehabilitation works on a major gully system at Crocodile Station in Cape York Peninsula, demonstrates that a 0.6-hectare gully system with a total erosion rate of around 260 tonnes per year has been effectively ‘turned off’ after two years at a cost of around $400 – $1,000 per tonne per year. More information about this project is available online.