Water failure—flood, drought, infrastructure collapse—is among the most common proximate causes of historical catastrophe, yet digital heritage simulation has not made it visible. Heritage reconstruction platforms model water as rendered geometry; water serious games model water as a contemporary management variable. Neither treats water as the interactive historical system that explains why places flooded, dried, or burned. A systematic survey of both fields confirms the gap: no verified example exists of a heritage game or platform that models hydrology, flooding, drought, irrigation, or water supply as the central interactive historical mechanic. This paper proposes water-as-protagonist as a game-design organising principle for historical simulation, translating a concept developed in environmental historiography and hydrosocial theory into a four-property design framework: water organises the historical narrative; the player intervenes in the water system; human consequences diverge; and replayability derives from engineering iteration on infrastructure layout. The platform architecture comprises per-location Regional Retrieval-Augmented Generation stores, time-slice switching across historical eras, a certainty shader that maps archival evidence quality to rendering style within a painterly aesthetic, a Community Memory System for post-disaster spatial data contribution, and interactive deployment of Adaptive Matrix Ecosystem infrastructure. Three demonstration scenarios—colonial drainage and lost wetlands (Auckland, 1920s), coastal storm surge (Miami), and landscape dehydration (New Zealand hill country)—illustrate the platform's generality. Competitive positioning against five benchmark systems confirms that no existing system combines water simulation, historical reconstruction, user agency, multi-site architecture, replayability, and uncertainty communication. The platform fills that intersection.
James Otto Danenberg (Thu,) studied this question.