Dear Mr Rann - what happened to the other 700 billion litres

Please read the attached document $1billion to fix the Murray Valley Irrigation says the Victorian Government. So the Australian Tax payer has just paid for that program. But the article attached also says that the water saving is going to be 800 billion litres. Mr Rann can you please tell me what happened to the other 700 billion litres? The taxpayer has paid, the River should get the benefit surely.