 The water forms a natural boundary for the Royal Gunpowder Mills as it passes through the mechanically controlled radial gates of the David Stoker sluice near Waltham Abbey.Now flowing parallel with the Lee Navigation, and only yards apart, the channel flows firstly under the A121 road and through Rammey Marsh Sluice - a set of three computer-controlled vertical lift sluice gates and then under the M25 motorway to be joined by Cobbins Brook before flowing through Newman's Sluice – a set of four computer-controlled vertical lift sluice gates.The channel crosses Rammey Marsh to form the eastern boundary of the former Royal Small Arms Factory, which is now a housing development called Enfield Island Village.