Flooding already imposes substantial costs to the economy. Costs are expected to rise in future, both as a result of changing weather patterns due to climate change, but also because of changes in exposure to flood risk resulting from socio-economic trends such as economic growth and urbanisation. Existing cost estimates tend to focus on direct damages, excluding potentially important indirect effects such as disruptions to transport and other essential services. This paper estimates the costs to commuters as a result of travel disruptions caused by a flooding event. Using Galway, Ireland as a case study, the commuting travel times under the status quo and during the period of the floods and estimated additional costs imposed, are simulated for every commuter. Results show those already facing large commuting costs are burdened with extra costs with those in rural areas particularly vulnerable. In areas badly affected, extra costs amount to 39% of earnings (during the period of disruption), while those on lower incomes suffer proportionately greater losses. Commuting is found to have a regressive impact on the income distribution, increasing the Gini coefficient from 0.32 to 0.38.