The Chelmer and Blackwater Navigation is the canalisation of the Rivers Chelmer and Blackwater in Essex, in the east of England.

It runs for 22 km from Springfield Basin in Chelmsford to the sea lock at Heybridge Basin near Maldon, with 11 locks taking the navigation down 23 metres to the sea.

An Act of Parliament was passed in 1793 authorising the construction of the navigation, and work began in October, with John Rennie as Chief Engineer, but with Richard Coates in charge in practice as Resident Engineer.

The navigation was opened throughout on 3 June 1797. Commercial traffic ceased in 1972, since when the navigation has survived solely on leisure traffic. The navigation is unusual in that it was not nationalised in 1948 along with most other waterways in the UK and is still under the control of the original Company of proprietors of the Chelmer & Blackwater Navigation Ltd, albeit as of 2005 in administration.

See Also

• Canals of the United Kingdom