During the last decades, the role of data as a vital resource that enhances decision-making and supports efficient systems operation has become evident, with a growing number of companies viewing data as a key organizational aspects that has to be properly managed, instead of an operational side-product. At the same time, drinking water systems increase in complexity and feature smart sensors, which in turn leads to data-richer operation environments for the water services. Given this challenging context, the often-overlooked factor of ensuring high data quality and preventing errors in data streams becomes increasingly important. In this chapter the current data validation techniques, challenges and best practices of the Dutch drinking water companies is presented.@en