Accurately monitoring water levels at high special and temporal scale is the key element in every catchment or flood risk management system. Building, evaluating and testing hydrological models typically require years of high frequency datasets. Current water level monitoring systems are expensive and usually deployed sparsely throughout a catchment. This may not provide sufficient information to simulate the hydrological variations of a catchment. In this paper, we evaluate the Kingspan Sonic SignalMan ultra-sonic sensor that is designed for monitoring liquid, such as diesel, AdBlue, lubricants additives etc., level autonomously over years. The cost of this sensor is relatively low, which enables the deploying of a water level monitoring system at a much larger spatial scale at an affordable cost. A smart sensor network for catchment management is proposed based on the use of the Kingspan sensor.