A watershed - the only place for water generation - was defined as only a physical resource based on old approaches. Water engineers were considering only physical resources of a watershed in a water plan such as soil, vegetation, and climate. This approach was only able to answer some questions about the management of natural resources while population growth and development of new technologies has changed socio-economic aspects of human societies such that pressure on these resources has been extensively intensified, resulting in new problems. To resolve these problems, it was necessary to behave more reasonably with the watersheds and to consider it as a whole and to provide integrated water resources management (IWRM) such that all resources of a watershed should be taken into account while preparing a master plan. To do so, an engineer must look at the vital symptoms of the watershed to understand where the problems are and what they would be. It means that an engineer must understand watershed health assessment through these symptoms. This new definition of watershed is based on a new approach to entire resources. It is no longer acceptable to define a watershed as only a physical resource, rather it should be considered as a living thing since the entire vital symptoms of human, animal, and plant lives flow in the watersheds. This approach can be the only approach to save all our waters within an IWRM plan.
