Presumably they will have a reading from the previous tenant.
If you leave and don't offer to pay ,once they realise the mistake they will pursue this.
At the end of the day you used the water so why should the owner have to pay.
What you are asking is do we think you will be able to get away without paying this bill.
Would you walk into a shop and walk out with a dress just because no one came up to serve you.
I hope you have saved the money to pay almost years water ,Why didn't you just tell them ,you could end up with a county court judgement over this .
You say its not your fault ,but I quite knew that hadnt taken the reading ,saying its not your fault in court wont wash.
Put it another way if they didnt take the rent from your bank each month would you have forgotten to tell them that too.
NuMILF Expectin' Miracle Bab ,you are something else,Will you teach your young children how to lie and cheat the system