University of California Water Resources Center

In Mediterranean climates, mild year-round temperatures support comfortable human settlement with rich agricultural regions. The climate’s long summer drought, seasonal river flow, high inter-annual variability in precipitation, and episodic floods threaten these settlements, leading to highly manipulated hydrologic systems.

The degree of hydrological alteration and consequent ecological change is typically much greater in Mediterranean-climate rivers than humid-climate systems. Dams, diversions, irrigation channels, storage and distribution facilities simultaneously restrict flow regimes, support economic development and destroy the native biological communities in Mediterranean drainage basins. Overcoming the complex relationships among climate, economy and our entangled legal and political institutions challenge the restoration potential of Mediterranean-climate river systems worldwide.