The Goulburn River connects the Hunter with the sandstone geology of the western part of the Hunter catchment. The sandy soils that are characteristic of this area are very easily eroded and in a large flood event, can result in large volumes of sand being deposited on the banks of the Hunter River at Singleton, Maitland and other areas further down the catchment.
Mr Alexander Wilkinson from the Maitland area described his experience of the flood of 1864 in the Moriarty Report of 1870:
"When we get the Goulburn River down in flood before the Upper Hunter comes, we get nothing but sand. If you walk around Horseshoe Bend, you will see a deposit of 16 inches at least from the 1864 flood; and if you notice the bank of the river, you will see the layers of sand and mud which have been deposited from time to time, according to whether the flood came from the Upper Hunter or from the Goulburn River" (Spencer et. al 2004).
The township of Denman was originally settled as Merton in 1825 by Lt. William Ogilvie, on the eastern side of the Hunter River and directly east of the current town. Over the years the settlement moved closer to the river and eventually crossed over to the western side. Subsequent flooding of the river continued to push the village west, away from the river banks to its present site, which still partly flooded up until 1988 when a levee bank was constructed to protect the town (Burkill, 2000).