Critically important decisions were needed on dam construction to ensure the survival of an endangered native fish population. We needed high confidence that the fish would use the artificial reefs proposed to replace their current habitat, which will disappear following reservoir enlargement and subsequent drawdown for water supply. A causal criteria approach, based on that used in epidemiology, was used to evaluate evidence in the scientific literature for and against fish using introduced habitat. Knowledge of life-history and species-specific habitat requirements was advantageous in creating a conceptual model of the system and highlighted the relevant factors. Published accounts of the placement of fish habitat were common in the body of literature but relevant studies of fish responses to habitat addition were less common. We evaluated 22 studies which collectively provided support for the hypothesis that the added habitat would result in an increase in fish density and abundance. With added confidence that the fish would use the artificial structure, a trial set of reef structures was added to the reservoir in preparation for a field-based experimental study aimed at gathering further evidence to ensure that adequate habitat is available to maintain, or enhance, the population of this endangered native fish.