Back to Water storages

Merrimu Reservoir

  • History

    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.

  • Purpose

    The water in the reservoir is primarily used to supply drinking water to Melton and Bacchus Marsh with the remaining used for irrigation in the Werribee Irrigation District.

    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.

  • Statistics
    Capacity 32,516 ML
    Dead storage 335 ML
    Surface area 420 ha
    Full supply level 174.1 m AHD
    Catchment area 85 km22
    Maximum height 45.3 m
    Length 400 m
    Crest length 30 m
    Discharge capacity 26,000 ML per day


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!