Portuguese hydrologist-artist duo Maria Vieira & Pedro Costa seized the D&AD Black Pencil for "Aqua Glyphs," converting Lisbon’s iconic Tram 28 tracks into real-time water conservation artworks. Partnering with Water Ministry hydrologists, they engineered capillary channels along rails that absorb overnight dew into thermochromic tiles – drought conditions turn tiles crimson to spell floating verbs like "save" and "collect" visible only at dawn. 

The participatory act requires passengers’ breath: exhaling onto window-mounted moisture collectors activates hidden nozzles releasing ephemeral rain curtains synchronized to fado music near historic fountains. Water usage data showed 37% consumption drop along the route within six months, while Lisbon University psychologists documented 68% increase in water conservation awareness. Berlin’s BVG transit adopted the technology to visualize groundwater levels near Spree River bridges.