Given that for integrated water resource management (IWRM) to be achieved, the current water management regimes needs to undergo a transition towards a more adaptive water management.
The answer of course is yes. Not sure which particular IWRM regime you are talking about given the diversity of water management across the world. Adaptive management is a core concept, variably given effect or lip service. But there are many core facets such as fair and transparent governance and laws, infrastructure, consultation during development, implementation and evaluation of rules, monitoring and its science, knowledge management etc. Your conclusion is correct given declining resources, climate change and rising human populations. All this is textbook stuff; the practical challenge is how to implement it within each local context and thereby collectively do this globally. Developing communities of practice has been core to this.