From the Wikipedia page [1]
The Thames Navigation Commission used to manage the River Thames in southern England. In particular, they were responsible for installing or renovating many of the locks on the river in the 18th and early 19th centuries.
The first Commission concerned with the River Thames was the Oxford-Burcot Commission, appointed in an Act of 1605 by James I. It took responsibility for the river between Oxford and Burcot.
The Oxford-Burcot Commission was reasonably successful. Thus, the Thames Navigation Commissioners were appointed through a further Act under King George II in 1751. This Commission had similar powers covering the whole of the river down to Staines.
Later, the Thames Conservancy was founded in 1857. Not long after, in 1866, it was considered best to have the navigation of the whole river under a single management, so the Thames Navigation Commission was subsumed by the Thames Conservancy.
An article by The Berkshire Record Society [www.berkshirerecordsociety.org.uk/Volumes/Volume12.htm here].