Aging infrastructure and a move towards sustainability have created new challenges for asset owners. On the other hand, advances in technology, such as low power electronics and sophisticated sensing methods, have made health monitoring of large infrastructure technologically feasible. However, despite the large body of research in this area infrastructure monitoring has not been widely adopted by asset owners of buried infrastructures. This is mainly due to complexity and high combined cost (production, installation and maintenance) of these systems. This paper describes the operation of a proposed non-intrusive relative pressure sensor, based on utilising low cost Force Sensitive Resistors (FSR). The paper also presents a novel method for detecting abnormal flow in pipes based on monitoring of the temperature differential between the pipe wall and its surroundings. The performance of these relative pressure sensors in conjunction with multiple temperature sensors has been assessed by deploying them for a period of 6 months on buried pipes at a water industry leak test training facility. The results showed that the proposed pressure sensors registered the expected systematic and daily pressure fluctuations in the network. In addition, the results showed that the calculated temperature differentials can be successfully used to detect abnormalities in the flow. This in conjunction with the relative pressure readings from the FSR based pressure sensors was shown to have the potential to be used to separate normal pressure variations from abnormal changes caused by pipe failure to provide a relatively low cost and easy to install monitoring system.