Water security and disasters are mutually linked. On the one hand, too much water (floods) and too little water (droughts) may constitute disasters. On the other hand, access to water is often a significant challenge during responses to disasters, notwithstanding if they are related to water. Water security plays a pivotal role in all stages of a disaster, from prevention and mitigation through disaster response to recovery and reconstruction. In disaster settings, water security is governed by a complex interplay of different branches of international law. These include international humanitarian law, international criminal law, international environmental and water law, climate change law, international refugee law and human rights law. The chapter seeks to discuss whether these regimes comprehensively govern and achieve water security in times of disasters; whether they have evolved into a body of international disaster law; and whether protection gaps remain and how these could be addressed.