 Finally passing through some of the town, it enters St George's College, Addlestone (formerly Woburn Park) where the River Bourne joins with the River Bourne (Chertsey branch).The River Bourne then by a manmade channel turns east instead of running the final 100m into the Upper Chertsey Reach; joining the River Thames below the southern weir of Shepperton Lock and its many islands, which due to the barraging of the Thames provides (as was possible before the Thames weirs were built) a greater fall.Along its lower course, past St George's College, Addlestone (formerly Woburn Park) the river becomes canalized and flows through 20 gardens of the Hamm Court estate, in the ecclesiastical parish of Addlestone and historically civil parish, but adjoining the Weybridge border to reach the Thames below Shepperton Lock.