Editors' introduction.

These populations rely on a mix of sources to meet their water needs, such as standpipes, water kiosks, sachet water and other informal water vendors such as tanker services. Since the nationalization of natural resources in Iran in the 1960s, local management of water resources has gradually become subject to national water policies. The pre-existing water management regime was rather successful because of the legitimacy of the communal rights, the presence of full collective property rights, and the appropriate scale of monitoring and sanctioning modalities. In Malawi, where water management is decentralized, the authors' tool could be of particular use in identifying areas where local-scale transboundary water management can take place. [Extracted from the article]