Glennies Creek Dam

Glennies Creek Dam is a minor ungated concrete faced curved earth and rockfill embankment dam with an uncontrolled rock cut spillway across the Glennies Creek, upstream of Singleton, in the Hunter region of New South Wales, Australia. The dam's purpose includes flood mitigation, irrigation, water supply and conservation. The impounded reservoir is called Lake Saint Clair.

Glennies Creek Dam was created through enabling legislation enacted through the passage of the. The Act appropriated AU$30 million as the estimated cost of construction of the dam.

Location and features
Commenced in August 1980 and completed in June 1983, the Glennies Creek Dam is a minor dam on Glennies Creek, a tributary of the Hunter River, located approximately 25 km north of Singleton and 39 km upstream of the confluence of Glennies Creek with the Hunter River. The dam was built by Citra Constructions Limited on behalf of the NSW Department of Land and Water Conservation and the NSW Department of Water Resources to supply water for the town of Singleton, as well as irrigation, flood mitigation, and for coal mining.

The dam wall height is 67 m and the arch crest is 535 m long. The maximum water depth is 56 m and at 100% capacity the dam wall holds back 283000 ML of water at 186 m AHD. The surface area of Lake Saint Clair is 1540 ha and the catchment area is 233 km2. The uncontrolled rockcut spillway is capable of discharging 637 m3/s. A 60 m high control tower with variable level inlets allows for the control of the quality and temperature of water released from the dam. Glennies Creek Dam is operated in conjunction with Glenbawn Dam. The two dams supply water requirements along 40 km of the Hunter River from Glenbawn to the tidal reaches near Maitland.

Glennies Creek Dam spillway is an unlined cutting in welded ash flow tuff which supplied the entire rock fill requirement for the construction of the dam embankment. The spillway excavation was designed to be located entirely in welded tuff and not to encroach on either the underlying non-welded tuff or the overlying sandstone, both of these rock types being much inferior to the welded tuff as a rock fill construction material.

The Glennies Creek and the Glennies Creek Dam are both named after James Glennie, a former naval captain who was granted creek frontage land near the Hunter River junction in 1824.

Recreation
The dam is a popular location for swimming, boating, sailing, water skiing and fishing.