Toorourrong Reservoir

Toorourrong Dam
Location of the Toorourrong Reservoir in Victoria
Country	Australia
Location	Whittlesea, Victoria
Coordinates	37°28′19″S 145°09′25″E / 37.47194°S 145.15694°E / -37.47194; 145.15694Coordinates: 37°28′19″S 145°09′25″E / 37.47194°S 145.15694°E / -37.47194; 145.15694
Purpose	Potable water supply
Status	Operational
Operator(s)	Melbourne Water
Dam and spillways
Impounds	Plenty River Diverted flows from the Wallaby and Silver Creeks
Reservoir
Creates	Toorourrong Reservoir

Toorourrong Reservoir is a small water supply reservoir located on the southern slopes of the Great Dividing Range approximately 40 kilometres (25 mi) north of Melbourne, Victoria, Australia. The reservoir is formed by the Toorourrong Dam across the Plenty River, and an interbasin transfer. The dam is operated by Melbourne Water and the reservoir forms part of the Melbourne water supply system. Water from the Toorourrong Reservoir flows by aqueduct to the Yan Yean Reservoir.

The reservoir is formed by an earthen embankment dam across the eastern branch of the Plenty River below the junction with Jacks Creek. The system was constructed in 1883–1885 as an extension of the Yan Yean water system. Water is diverted from Wallaby and Silver Creeks, part of the Murray–Darling basin on the northern side of the Great Dividing Range — via the open, granite-lined Wallaby Aqueduct — across the Great Dividing Range just east of Mount Disappointment, then into Jacks Creek and into the reservoir. The reservoir acts as a settling basin before the water travels 8 kilometres (5.0 mi) down the Clearwater Channel to Yan Yean. The reservoir catchments are within the Wallaby Creek section of the Kinglake National Park.

The Yan Yean Reservoir, completed in 1857, was Melbourne's first water supply system. In 1879 low dam levels showed that further water sources were necessary to meet increased demand by a growing population. The Wallaby Creek aqueduct was constructed in 1882–1883 to divert water via an interbasin transfer from Wallaby Creek via Jacks Creek and the Plenty River to Yan Yean. The reservoir was constructed in 1883–1885 and linked to Yan Yean by the Clearwater Channel aqueduct, and the Wallaby Creek aqueduct was extended north to harvest Silver Creek. Public Works Department engineer William Thwaites designed most of these works. As water quality in the lower Plenty River had deteriorated, the intake from the river at Yan Yean Reservoir was closed and all water supply was drawn from the closed forest catchments via Toorourrong.