In particular, it is not fit to study some of the important linkages between water and energy outlined in Chapter 1. First, the modelling tools can only capture systemic effects that are noticeable in the top-down frameworks, and ignore important local bottlenecks with severe local consequences that may occur over short time spans. Secondly, there are significant data gaps (see e.g. OECD, 2010) that prevent a full representation of all the bottlenecks in the baseline and counterfactual projections of the modelling tools.