A 'Main River' is defined as a watercourse shown as such on a Main River map held by the Environment Agency and the Department for Environment, Food & Rural Affairs in England (DEFRA). Main Rivers can include any structure or appliance for controlling or regulating the flow of water in, into or out of the Main River. The Environment Agency’s powers to carry out flood defence works apply to Main Rivers only. Main Rivers in England are designated by DEFRA.
The Bank Top e-planning Tool denoting the 20 metre GDPO consultation zone was provided to all English LPA's via CD on 12th April 2007. There is an option to amend this consultation requirement to reflect local byelaw distances in circumstances where agreement is reached between the LPA and the local Environment Agency office.