West Barwon Reservoir

CATCHMENT CATCHMENT

SURFACE RUNOFF SURFACE RUNOFF SURFACE RUNOFF

GROUNDWATER WURDEE BOLUC WATER TREATMENT PLANT WEST BARWON BORE RESERVOIR WURDEE BOLUC WURDEE BOLUC RESERVOIR INLET CHANNEL MUNDAY CREEK WEST BARWON RIVER WEST BARWON AQUIFER RESERVOIR WURDEE BOLUC INLET PIPE DAM WALL

Water is essential for life. History surrounding hills results in a catchment of Water quality Geelong’s first reservoirs were constructed on approximately 51 square kilometres, directing Although untreated, this water will eventually Its cycle from the surface the Moorabool river system in the 1870s, but a all rainfall within this area toward West end up as drinking water. To aid in the of the planet to the sky, to growing population and subsequent increase Barwon Reservoir. treatment process, it is critical the water clouds, to rain and back to in demand for clean water necessitated a new Surface runoff is kept as clean as possible from the very water source. The then Geelong Waterworks beginning. For this reason, the reservoir is the surface is continuous, and Sewage Trust turned to the upper Barwon As the rain falls, surface runoff flows down off-limits to bathers, domestic animals and all catchment for Geelong’s next reservoir. the steep forested hills toward streams, forms of boating. and one of the fundamental creeks and rivers. The water continues along natural processes on which Work began on the West Barwon dam in 1959 the tributaries before flowing into the West Dam wall and the reservoir was officially opened in 1965. Barwon River and Munday Creek. Built at the junction of the West Barwon we depend. At the time of construction, West Barwon was Reservoir River and Munday Creek, the dam wall is Its journey from the environment to the largest reservoir project in Victoria. constructed from zoned earth and rockfill, The water eventually finds its way to West our homes involves long distances and with an upstream sloping clay core to reduce Catchment Barwon Reservoir where it is stored for future specialised equipment that transforms this seepage. Most of Geelong’s water supply originates use. The reservoir holds approximately 21,500 natural resource into drinking water for within the picturesque Great Otway National megalitres (million litres) when full – enough almost 300,000 permanent residents of the Park where the average rainfall is double for approximately six months’ supply for the Geelong region. that of Geelong. The natural contour of the greater Geelong region.

OUTLET TOWER

WEST BARWON RESERVOIR

SPILLWAY DAM WALL

VALVE HOUSE

WEST BARWON RIVER DIVERSION POINT GROUNDWATER BORE

WURDEE BOLUC INLET CHANNEL

AQUIFER CATCHMENT CATCHMENT

SURFACE RUNOFF SURFACE RUNOFF SURFACE RUNOFF

OUTLET TOWER

WEST BARWON RESERVOIR

SPILLWAY DAM WALL

VALVE HOUSE

WEST BARWON RIVER DIVERSION POINT GROUNDWATER BORE

WURDEE BOLUC INLET CHANNEL

AQUIFER

Did you know? Spillway Diversion point Treatment plant Catchment area 51 km2 In the rare event of flood, a large concrete Approximately 400 metres downstream of At the Wurdee Boluc Water Treatment Plant, weir, spillway and chute release the overflow the valve house, water is diverted through a untreated water is dosed with a special Reservoir surface area 1.76 km2 safely around the dam wall, directing the 600 metre tunnel to the West Barwon River. chemical that ‘glues’ dirt particles together (when full) excess water to the West Barwon River below. A further 5 kilometres downstream the water into a ‘floc’. This water is then passed Capacity (when full) 21,504 ML is diverted again into the Wurdee Boluc inlet through filters that remove the floc particles Usable volume 20,900 ML Outlet tower channel. and leaves the water crystal clear. Max depth of reservoir 21.4 m The outlet tower acts as the ‘plug hole’ for the reservoir. The 30 metre tall concrete Wurdee Boluc inlet channel The final step is the addition of a small amount Length of dam 320 m structure draws water from the reservoir and The Wurdee Boluc inlet channel is a of chlorine to inactivate any micro-organisms Height of dam 43 m delivers it through a 150 metre tunnel to the 57 kilometre concrete-lined channel that that may be present. Fluoride is also added at Width of dam wall (top) 9 m valve house below the dam wall. transfers untreated water from West Barwon this point to help reduce tooth decay. Reservoir to Wurdee Boluc Reservoir. Width of dam wall (base) 125 m Valve house The water is now clean and safe to drink, and is sent on its way toward residents Elevation of dam wall 172 m At the valve house, the flow of water is Groundwater of greater Geelong. (above sea level) regulated via a cone-shaped valve. The In times of reduced rainfall, groundwater Length of outlet tunnel 170 m valve has the capacity to release up to is used to supplement surface water. Diameter of outlet tunnel 3.3 m 300 megalitres a day (3,500 litres/sec). To Groundwater is found in underground water maintain river health, a minimum amount of bodies called aquifers. Water can be extracted water must be released. This water is termed from an aquifer using a bore and pump. the ‘environmental flow’ and is equivalent to 4 megalitres a day (45 litres/sec). Wurdee Boluc Reservoir For further information Untreated water is stored within Wurdee 1300 656 007 Boluc Reservoir before being transferred to [email protected] the water treatment plant for filtration and disinfection. www.barwonwater.vic.gov.au