Can tenant be reimbursed for piped water when the water tank fails?

This week’s question comes from Anonymous:  

My tenant (from 2016 to 2020) has made a Tribunal application against me. She is claiming, among other things, reimbursement of water rates due to the roof and gutters not being cleaned rendering the water tank unusable. Is that a valid claim? 

Without further information, we assume the following:

• That the property has both reticulated water supply and a water tank; 
• The tenancy is not provided on the basis that the property is on tank water only; 
• That the property complies with all building, health and safety requirements irrespective of the landlord’s failure to clean the roof and gutters;
  and 
• That the tenant is seeking reimbursement for only variable/consumption-based water charges.

• s45(1)(b) The landlord shall provide and maintain the premises in a reasonable state of repair having regard to the age and character of the premises
  and the period during which the premises are likely to remain habitable and available for residential purposes.
• s45(1)(ca) The landlord shall if the premises do not have a reticulated water supply, provide adequate means for the collection and storage of water. 
• s45(2)The landlord shall not interfere with the supply of gas, electricity, water, telephone services, or other services to the premises, except where
  the interference is necessary to avoid danger to any person or to enable maintenance or repairs to be carried out. 

Seeing that the tenant has been charged and paid for water rates, we assume the...