Water allocation is becoming ever more important and, in many cases, ever more contested. Institutional measures are a critical part of allocation policy frameworks. Over the past few decades, several countries have implemented institutional reforms to improve their water allocation and rights frameworks. These water allocation reforms have provided useful lessons but cannot lead to universal blueprints for good allocation institutions. This Element takes stock of the emerging lessons from recent experience. The authors review three main types of institutional instruments for allocation: regulatory, economic, and collective action approaches. This is done for a comparative analysis across over 100 countries, combined with in-depth country case studies that help link policy and operational practice. The authors conclude with reflections and suggestions for transition pathways towards resilient, equitable, and sustainable water (re-)allocation institutions. This title is also available as Open Access on Cambridge Core.