Each of the three Melbourne Water Retailers would probably approve around 2-3 build overs a week. (In a previous job I used to be work for a company that carried out the CCTV surveys which are a requirement of the approvals)
Check out this link it will give you a good idea of whats required: http://www.yvw.com.au/easyaccess/knowledgehub/display/PO/Applying+for+a+Build+Over+Easement+conditions
