The reservoir was constructed in three stages from 1969 to 1986 and has a capacity of about 32,000 ML.
The reservoir has a small natural catchment area, so to supplement its storage ability, two small diversion weirs and two tunnels from neighbouring catchments were built. These works and the subsequent raising of the reservoir embankment form the three main stages of the Merrimu Reservoir construction.
Merrimu Reservoir provides better management and regulation of water flows in the Werribee Basin, consequently increasing the security of supply to Werribee and Bacchus Marsh irrigation districts, urban water and industrial supplies in the Melton and Bacchus Marsh areas.
Merrimu Reservoir is located on Pyrites Creek, a tributary of the Werribee River, 10kms north-east of Bacchus Marsh and approximately 50kms from Melbourne.
Please check the water levels (see graph at the top of the page) before planning a day out at the reservoir!
|Dead storage||335 ML|
|Surface area||420 ha|
|Full supply level||174.1 m AHD|
|Catchment area||85 km22|
|Maximum height||45.3 m|
|Crest length||30 m|
|Discharge capacity||26,000 ML per day|