As the world gets more and more water stressed, those who control water supplies in rivers, lakes and dams, will exercise more power and restrict access to water to those downstream. This could lead to conflict - legal and physical - that is both internal and crosses national boundaries. Some countries may even use the need for water as a reason to invade a neighbour. Whether as an individual or a business, or a region or country, we need to have a plan for water security that is equitable, agreed on by everyone, and future proof. We cannot live without water.