The Basin Plan aims to balance the water needs of the environment and other uses, through the establishment of new limits (known as sustainable diversion limits, or SDLs) on the volumes of water use. Drawing on the best available information and advice, the Authority has: - assessed flow regimes at 122 environmental sites throughout the Basin - taken account of physical constraints that limit the volume of water that can travel down a river - looked at how water is shared between the environment and other users, with arrangements in 2009 used as the reference point (or "baseline") and including around 959 GL of environmental water recovered in the Basin prior to 2009 (of which 136 GL has been returned to the Snowy River). - taken account of potential social and economic effects. Based on this assessment, the Authority is proposing a long-term SDL of 10,873 GL/y. This would see an additional 2,750 GL/y of water returned to the Basin's rivers, including: - 1,636 GL/y to meet the local environmental water needs within catchments - 971 GL/y to meet the shared downstream water needs of the River Murray - 143 GL/y to meet the shared downstream water needs of the Barwon-Darling.