Urban riverfront interventions are ubiquitous throughout the developed world, and increasingly also in the Global South. Many have failed spectacularly. We conducted a systematic review of failed riverfront interventions to draw lessons that could improve future projects. Learning from past mistakes may be more important than observing successes, because successful elements in one city may not be repeatable elsewhere, as the context and opportunity could be specific to that one city. Recognizing what did not work elsewhere may provide clues needed to improve future projects. Our results show that poorly designed riverfront interventions typically fail on several levels: a bad program, with the wrong budget and timing, no concern for local needs or context, results in an unattractive and costly intervention, with reduced to no social or environmental benefit. To create more successful interventions in the future, we should acknowledge the local context, the morphology of the river valley, the time and budget a set of solutions entail, and select uses and functions that work for a diverse crowd and provide multiple benefits, including good flood management performance and the restoration of the rivers’ natural connectivity.

Mega-events such as the Olympic Games are powerful tools for city-branding and urban development, carrying the ability to create lasting physical, political, social, and economic legacies. Waterfront redevelopment has become a primary mechanism for revitalizing urban spaces, especially through brownfield requalification, and the Olympics have not been indifferent to this trend. Several recent editions have engaged in the rehabilitation of urban waterfronts. To analyze common mistakes that may impair the quality of these interventions, we apply a revised version of a binary evaluation tool to nine such Olympic Waterfronts, starting with Barcelona 1992, assessing their contexts, budgets, programs, plans, and environmental integration. The results show that the Olympic Waterfront can drastically change the image of the city, greatly contributing to the perceived success of the event’s legacy and creating new urban centralities. However, the inadequate management in the planning, delivery and, especially, legacy stages of the event can compromise this “Olympic Effect”. The test application of the evaluation tool proved successful in the context of mega-event planning and post-event transformation. It could potentially be useful in informing present and future decision-making regarding waterfront regeneration projects by highlighting pressure-points that, if not addressed, may hinder the future success of the interventions.