The Environment Agency is the principal flood risk management operating authority. It has the power (but not the legal obligation) to manage flood risk from designated main rivers and the sea. These functions in relation to other rivers (defined as ordinary watercourses) in England and Wales are undertaken by Local Authorities or Internal Drainage Boards. The Environment Agency is also responsible for increasing public awareness of flood risk, flood forecasting and warning and has a general supervisory duty for flood risk management. As of 2008[update] the Environment Agency also has a strategic overview role for all flood and coastal erosion risk management. The term 'Flood Risk Management' in place of 'Flood Defence' recognises that managed flooding is essential to meet the requirements of a sustainable flood strategy. It is often not economically feasible or even desirable to prevent all forms of flooding in all locations, and so the Environment Agency uses its powers to reduce either the likelihood or consequences of flooding.