Summary

Often the focus on sustainability issues centres around energy supplies, and the depletion  of non-renewable resources.  This chapter has outlined that access to clean water is as much of a problem if not more so, and although considered a ubiquitous renewable resources, we have shown this is only the case if treated with care and consumed and treated in a sustainable manner. 

Water is essential for life, and freshwater supplies worldwide are depleting through over use and pollution.  We have covered water supply worldwide, which countries are in water debt and what the major uses for water are worldwide.  Water supply is becoming an increasingly important geopolitical point of concern, and engineers with their ability to design and implement infrastructure for water supply, and with knowledge on sustainable water systems will be invaluable in advising policy decision making and ensuring the worlds growing population has access to the element essential for survival.