No / Sewer and gully flooding have become major causes of pollution particularly in the residential areas majorly caused by blockages in the water system and drainages. An effective way of avoiding this problem will be by deploying some mechanism to monitor gully pot water level at each point in time and escalating unusual liquid levels to the relevant authorities for prompt action to avoid a flooding occurrence. This paper presents a low cost power efficient gully pot liquid level monitoring technique. Passive RFID tags are deployed and signal variation from the Alien Reader Software are used to effectively estimate the level of liquid in the gully pot. The experimental set up is presented and an expository presentation is made of the passive tag design, modelled and simulated and adopted for same application.