Some additional locks were added, and by 1795, there were fifteen, three made of masonry blocks, and twelve with turf sides. There were also two single gates or half locks. The lowest lock was at Woodmill, where the navigation joined the estuary of the River Itchen, on its way to Southampton Water. The main wharves at the Southampton end were at Northam, about below the lock, and barges worked down to them on the tide or were punted if the tide was rising. As the river was tidal below Woodmill Lock, the structure was rebuilt in 1829 with a third set of gates facing downstream, to prevent high tides flooding the navigation.