Chapter 2 reviews the specific characteristics of aquifers, and the main issues they currently face and will face in the future. Chapter 3 reviews groundwater management policies based on a 2014 OECD country survey. Chapter 4 reports the policies in place in OECD countries, and the final chapter identifies gaps and proposes potential improvements for agriculture groundwater policies. On the discharge side, natural uses and flows operating both vertically and horizontally in aquifers increase the complexity of the picture.