geographical environmental and economic factors also have a considerable impact there is a diversity of situations across oecd federal and unitary states in terms of the institutional organisation of water policy on the other hand though some unitary states still retain significant water responsibilities at central government level with highly centralised water policy making korea chile israel most oecd unitary states france new zealand greece the netherlands have de facto delegated many responsibilities to lower levels of government these models are not intended as normative in the sense that one would be better than the other but they highlight different coordination challenges raised by a given institutional organisation of water policy even if within a same category the degree to which governance challenges have an impact on the performance of water policy may vary from one country to another in addition to outlining the challenges to coordination they could be enriched by adding other dimensions eg capacity gaps variety of tools in use etc