In this paper, I compare reflections from my action research engagements with two Murray'Darling Basin (MDB) natural resource management (NRM) organisations, Murrumbidgee Irrigation (MI) and Murray Catchment Management Authority (CMA) in NSW, Australia. My engagement with MI (2005'2007) coincided with the most extreme years of the extended Millennial Drought. The research engagement with Murray CMA (2009'2012) occurred as the Millennial Drought ended, and coincided with the 2010'2011 floods and local community anger over plans to reduce irrigation allocations in the MDB. Both organisations were also undergoing cultural change inspired by concerted efforts to promote widespread staff participation in evaluation, reflection and learning. While I observed considerable organisational learning at MI, staff recounted constraints on making substantial advances towards sustainable water use practices across the MDB because of limitations on MI's sphere of influence. Murray CMA, on the other hand, was charged with the development of a 'whole-of-community' strategic plan. This required the development of organisational strategies that achieved both organisational change and the creation of opportunities for broader social learning. Murray CMA's recognition of the importance of the social dimension is a critical element of the 'double-loop' learning that I argue enabled a transformation of the organisation's culture.