Water permeates every aspect of life; as such, water connects with all the SDGs in myriad and complex ways. Inevitably, this means that progress towards SDG 6 will be determined as much by what happens in other sectors as by those actions taken within the water sector (ICSU 2017). The 2030 Agenda emphasizes the importance of these linkages and the immense benefits an integrated approach can bring to sustainable development. Understanding these can help to ensure the appropriate timing and sequencing of policy and institutional reforms and public investments so that limited resources are used more efficiently and sustainably.

Endless reports describe and discuss the linkages and agree that integration across all the SDGs and within SDG 6 (see Section 4.2) will be vital. However, too often, they are intuitive; they tend to say what should be done rather than how to do it and lack data and analysis to strengthen qualitative arguments. The SDG 6 monitoring system is beginning to change this (see Chapter 3). It provides a wealth of information which can take discussions beyond rhetoric and offer the evidence needed to demonstrate the importance of water connections, particularly those which maximize synergies and reduce the risks that actions to meet one goal, if not well explored, can undermine other goals. For example, decisions on types of energy generation can significantly influence water demand, while growing biofuels can displace food production.

Although water touches all the SDGs, some linkages are more important than others, and so in this chapter we focus on those linkages that can bring the most benefit. The global financial, energy and food crisis in 2007– 08 reminded everyone that water, energy and food (WEF) connect in vitally important ways, and each sector has the potential to significantly help or harm the other two. In 2011, the Bonn conference on “Water, Energy and Food Security Nexus – Water Resources in the Green Economy?” called for a new approach addressing water security based on IWRM and including WEF. It argued that IWRM was too water centric and suggested a nexus approach stressing a WEF nexus, which focused more on the interrelationships between water, energy and food and included other vital resources, such as land and soil (Hoff 2011).