In Drinking Water treatment plants (DWTPs) is critical make an early fault detection and diagnosis for warranty a qualified service, this is helpfully for a good take decisions process on day by day operations This paper presents the development of a rule based supervisory system, that uses fuzzy logic for predict fails in turbidity sensor on water intake stage zone, those rules were built for expert's information and historical reviews. In this sense, this paper introduces a practical example on a turbidity sensor located on Puerto Mallarino DWTP's water intake stage from Public Service Company of Cali (EMCALI EICE ESP), Colombia.