Within the humanitarian arena and since the introduction of the humanitarian reform process in 2005, the cluster approach was introduced to strengthen the cooperation and accountability between agencies working in the same field. Such an integrated approach is particularly needed and relevant in emergencies like cholera, especially in countries undergoing internal conflicts like Yemen. Several areas of concern have been identified during the past field experiences, which include dysfunctional cooperation as a result of different mandates as well as the relationship between nongovernmental organizations and their donors. Control of environmental health services is, for instance, the responsibility of several clusters/agencies and stakeholders, which usually results in a complicated and sometimes confusing approaches to address gaps and barriers. As far as the drinking water quality monitoring and surveillance are concerned, sampling and testing and compilation of data are usually carried out by many agencies included in the health and water sanitation and hygiene (WASH) clusters. We believe that the cluster theoretical approach for emergency response remains a turning point for the humanitarian arena. However, lessons from the recent past, especially in the management of a cholera outbreak in fragile settings, may serve as a serious reflection on roles and dynamics within the blurred border between health and WASH. Specifically, cluster leads in the field have the responsibility for ensuring that humanitarian actors working in their sectors remain actively engaged in addressing crosscutting concerns such as the environment.
