This article summarises research-in-progress for improved risk assessment and management (RAM) of critical infrastructures that interconnect across California's Sacramento-San Joaquin Delta. The need for improved RAM is patent in the Delta as elsewhere: a 'patch and pray' stalemate has developed which focuses on short-term reactive marginal maintenance and emergency response and recovery systems, all pushing infrastructures - and their engineers, designers and operators - increasingly to their performance edges and beyond. The research focuses on water supply, transportation, energy and flood protection systems, all of which are embedded in a dynamic ecosystem and showing clear signs of deterioration. Provisional findings of research activities are discussed. This article addresses critical infrastructure modelling uncertainties and ways to better understand, reduce or otherwise accommodate human/organisational and informational uncertainties in any RAM focused at the interconnected critical infrastructure system level.