Below the bridge is a small island, after which an artificial cut built to avoid the circuitous route of the River Rother Navigation heads westwards. The river now discharges over a weir at the site of the former Hardham corn mill to join the Arun a little further downstream, and the junction is followed by another small island. Hardham lock was necessary because of the drop in levels caused by the mill, and the branch through Hardham tunnel headed due south a little further up the Rother. Exploration of the tunnel was described by an article in "Sussex County Magazine" in 1953, when both ends were accessible, and again in 2012, when only the southern end was explored. A waterworks has been built over the bed of the canal at the northern end, and the tunnel mouth is within the site. The river continues in a large loop to the east. The Arun Valley railway line crosses it to reach Pulborough railway station. There is another island, with the A29 road crossing both channels. Pulborough Brooks nature reserve is to the east of the loop, and the course then meanders westwards to Greatham Bridge. The bridge consists of eight low elliptical arches, two taller arches, a cast iron span over the navigable channel, and a solid ramp to the east. Although its construction suggests that it is medieval, most of the arches were erected in 1827.