Some 90% of the Guyanese population are at risk from contemporary flood hazard and the potential impacts of climate change and sea-level rise. Such risks are not the product of physical systems alone, and by using a political ecology frame the geography of ¯ood hazard in urban environments can be seen to coevolve with political, social and economic systems. These systems are explored by a historical review which traces the roots of present vulnerability to the colonial experience, and an analysis of contemporary vulnerabilities which draws from a peri-urban and an urban case study. The case studies show that the current fashion in international donor agencies to fund Ôcommunity sponsored developmentÕ has missed an opportunity to enhance security through grassroots empowerment, and rather that those community organisations associated with this system have been co-opted by political elites reproducing embedded distributions of power and vulnerability. Ó 1999 Elsevier Science Ltd. All rights reserved.