Complex sentence: The source of Costa Beck is Keld Head Spring to the west of Pickering, and it is a tributary of the River Rye which joins the River Derwent, eventually flowing into the River Ouse at Barmby on the Marsh.
Split into simpler sentences: The source of Costa Beck is Keld Head Spring to the west of Pickering. It is a tributary of the River Rye which joins the River Derwent, eventually flowing into the River Ouse at Barmby on the Marsh.