Mapping water is neither a linear nor a generic operation: it requires a close and a systemic reading throughout the different spatial, socio-economic and political dimensions of water. Water has to be unfolded in its full complexity, not only as a technical matter. “Water-taal” visualizes water(s) in the Dender valley – both in Flanders and in Wallonia – via a threefold set of (mapping) operations that, in their process of making, will continuously inform each other: the deconstruction of whole water system(s) into a unique catalogue of water elements; the reconstruction of the same elements into synthetic spatial representations of water systems and flows, where quantities and qualities are visualized at once in a synchronic view; the identification of a set of potential territorial water sequences.