Williams River

Overview

 

Catchment area

974km2

Annual rainfall

1152mm (at Dungog)

Areas supplied

Water pumped into Grahamstown Dam at Seaham Weir

Land use breakdown of catchment

80% farming and rural, 14% National Park or State Forest, 6% Hunter Water freehold

Northern reaches

The Williams River begins in forested and pastoral land approximately 140 kilometres north of Newcastle.

The first waters of the Williams drain from the southern Barrington Tops National Park and pastoral hinterland. To the east, the Chichester River also begins in the Barringtons and joins the Williams at Bandon Grove. Land use in the northern reaches is a mixture of National Park, forestry and extensive cattle farming with some irrigated pasture cropping on the river flats.

The Williams continues in a southerly direction through the major townships of Dungog and Clarence Town. The catchment of this portion of the river is again primarily pastoral, but with pockets of more intensive agriculture (e.g. poultry and dairy farms) and urban development.

Southern reaches

At Mill Dam Falls (approximately 45 kilometres from Newcastle) the Williams changes from a free flowing river into a modified river weir pool known as Seaham Weir. The weir is approximately 18 kilometres in length and is free from tidal influence.

On average the weir pool is between 5 and 8 metres deep and must be maintained at a specific level to reduce erosion of the river bank and prevent flooding of the surrounding property.

After rainfall and under higher flows, water is transferred through Balickera Canal to Grahamstown Dam using pumps at Balickera Pump Station. During dry times the majority of flow in the Williams is sourced from the upper catchments and during wet times the lower catchment dominates.