Paradoxically, the water that once afforded Venice its power as a maritime empire now compromises its physical integrity. Periodic flooding threatens both the historic city and the mainland. Specifically, the increased frequency and severity of flooding is perceived by many as a threat not only to public health, but also to the liveability and economic viability of the historic centre. Floods have both short-term implications (reduced tourism-related income, increased costs of routine logistics) and long-term implications (notably damage to the city's building fabric and architectural heritage) for the Venice city-region.