River Chess

The River Chess is a chalk stream which springs from Chesham, Buckinghamshire and runs through Buckinghamshire and Hertfordshire, in south-eastern England. The Chess, along with the Colne and Gade, gives rise to the name of the district of Three Rivers, in which it forms its confluence with the Colne at Rickmansworth. The River Chess falls 60 m and is 17.9 km long.

More information on the Wikipedia page