The humanitarian context you describe is clearly a unique and particularly challenging situation. Floods and other disasters destroy homes and livelihoods, leaving households in tenuous situations, rife with horrible environmental sanitation contexts. Building adaptation capacity to these challenges is a major way to provide security to households.
In a more general/non emergency context, I think that there should be a greater focus on the distinction between the issues behind IWRM-scale scarcity and mis-allocation/poor management of bulk water and determinants of access to drinking water.
Ultimately, access to water is often a factor of affordability of water and accountability (or failure) of governments to provide and as is cited in the report's summary:
"(1) failure to provide citizens with basic water services;
(2) failure to protect citizens from water-related disasters; and
(3) failure to preserve surface, ground and transboundary water