The Sulham Gap is a distinctive valley in the English county of Berkshire. Following a late Devensian drainage diversion, the Sulham Gap lowland was left as a poorly drained former floodplain. A major flood, with an unprecedented magnitude, occurred in July 2007 sourced primarily from the River Pang which enters the gap on the western side. Its physical impact was exacerbated by: 1, medieval extraction of postglacial peat; and 2, the building of leats for watermills. The flood water drained across the topographically lower drainage network of the diminutive Sulham Brook to the eastern side of the gap and backed-up behind culverts beneath both a road and a railway embankment resulting in some 140 homes being inundated.