The catchments of the Idle and Torne rivers cover an area approximately 1,200km² spanning the counties of Nottinghamshire, North Lincolnshire and South Yorkshire. Doncaster is the most significant conurbation in the Torne with Mansfield, Worksop, Retford, Maltby and Bawtry significant urban areas in the Idle.
The Rivers Maun, Meden and Poulter meet south of Retford to form the River Idle, joined downstream by the River Ryton. At Bawtry, the River Idle turns eastwards to its confluence with the River Trent at West Stockwith.
The River Torne rises near Tickhill and flows northeastward, through the heavily drained area of the Isle of Axholme to its confluence with the River Trent at Keadby.
Arable cropping is the dominant land use and much of the northern half of the catchment is drained by pumps and high level carriers because the land is at or below sea level. There are a number of Sites of Special Scientific Interest (SSSIs) in the catchments and the Thorne and Hatfield Moors Special Areas of Conservation.
The River Idle Catchment Partnership is hosted by Nottinghamshire Wildlife Trust. More details can be found at https://www.catchmentbasedapproach.org/humber/idle
The River Torne Catchment Partnership is hosted by the Yorkshire Wildlife Trust and more details can be found at https://www.catchmentbasedapproach.org/humber/torne