In this paper, a methodology for data validation and reconstruction of flow meter sensor data in water networks is presented. The raw data validation is inspired on the Spanish norm (AENOR-UNE norm 500540). The methodology consists in assigning a quality level to data. These quality levels are assigned according to the number of tests that data have passed. The methodology takes into account not only spatial models but also temporal models relating the different sensors. The methodology is applied to real-data acquired from the ATLLc Water Network. The results demonstrate the performance of the proposed methodology in detecting errors in measurements and in reconstructing them.