if the landlord doing tax return, why do you brother asking tenant to pay water bill/gardening etc? you can always claim back as expenses when you doing your tax return...The condition is you claim you property as rental property....
You can include a condition in the lease agreement that a tenant pays for their own water consumption. You must give the water accounts to the tenant as they become due. If you do not provide these accounts and have had every opportunity to do so the tenant may only be held responsible for part of the account.
If the property is on a separate water meter you can ask that they pay the entire water consumption bill and the supply charge by including this as a condition on the lease agreement.
If the property is on a shared meter you can still ask that the tenant pays for water. It is recommended to calculate water charges as a percentage in these cases - eg water meter is shared between two rented properties, each tenant is charged 50% of all water usage. "