The Victorian state government rebate scheme for rain water tanks, as of 30th June 2007, is summarised in the table below.  This applies to those wanting to install a rainwater tank in Melbourne suburbs as well as regional centres.

Rainwater Tank size: 2000 - 4999 litre capacity
Requirements: connected to toilet and/or laundry
Rebate: $500

Rainwater Tank size: 5000+ litre capacity
Requirements: connected to toilet or laundry
Rebate: $900

Rainwater Tank size: 5000+ litre capacity
Requirements: connected to toilet and laundry
Rebate: $1000

A $150 rebate for tanks 600 litres or larger not connected for indoor also applies.

See Our Water Our Future website for more.