Book excerpt: Hydrological variability, increasing competition for water, and the need for regulatory flexibility may increasingly compel governments to adopt measures with significant economic impact on foreign investment. In International Investment Law and Water Resources Management, Daza-Clark offers an appraisal of indirect expropriation, revisiting the well-known doctrine of the police power. Through the lens of international investment law, the author explores a framework that assesses the legitimate exercise of police power with particular attention to the special nature of water resources.