A charter in 1197 first gave conservation rights for this river to the Mayor and Corporation of London. Above Staines, local communities maintained the river. Boats were able to reach Oxford from the twelfth century. There were gradual improvements and in 1771, an important Act of Parliament was passed increasing the number of commissioners and dividing the river into five districts above Staines. The new commissioners were granted wide powers of improvement and built eight new pound locks.
There is an obelisk 230 yards (210 metres) below Teddington Lock showing the boundary of the Environment Agency's responsibilities with the Port of London Authority, which manages the tidal river.