Tenant denying to pay Maintenance Fee

As per lease agreement of 11 months, 16k rent and 500Rs maintenance fee. (verbally communicated this is equal to 5000L water expense at that time) As in Bangalore the water scarcity started. The tanker rate currently increased and stands at 1000Rs for 5000L. we have 5 kitchen houses in the building and we get 40000L avg cauvery water. So I installed water meter for each individual house. And based on the usage and agreed by all tenants the water usage will be charged. One tenant who consumes 30-40% of cauvery water. Allocated 20% per household. Is denying to pay for tanker charge for extra 20% consumed. And threatening to not pay and vacate the premise. Water usage is not mentioned as clause in the agreement. As this is my new house (extended the floor for rent). But there is a clause which say " The either parties shall give one (1) month notice while vacating the premises. Still 3 and half months is left for 11 months completion. Q- Can I ask the tenant to vacant by filing the notice of eviction for 1 month. What if they don't vacate. Q- Shall I ask the tenant to pay water usage fee atleast 500Rs as per agreement and for extra usage (through tanker) as per their will. And vacate the premises by 11 month completion.