Water Supply - Unauthorised usage of pumps

I have written letters to the society on this but there has been virtually no action. I was given to understand that some tenants in neighbouring shops were using pumps to draw water and that could be reason of water not reaching my shop. I enquired about this with the Society and they informally confirmed about them being aware of this. At the same time they expressed helplessness in doing anything about it as they had no powers to inspect the premises and seize the pumps being used. Also they said a complaint to municipal authorities would not really solve the problem as the tenants would resort to bribing officials and continue the malpractice. In the past the Society has issued notices some members against the illegal encroachments on common space carried out by their tenants. This has not yielded any compliance. On a personal level the Secretary advised me to use a pump myself to solve my water shortage problem! Pl advise what is the best way to address the problem. Thanks.