Flooding from extreme rainfall events is one of the major natural hazards affecting Jamaica and other small island states in the Caribbean. Jamaica has already experienced several major floods in the last decade, resulting in damages to infrastructure and loss of life. The value of social and economic assets exposed to hazards in Jamaica has been estimated at US$18.6 billion, with a large portion of this value occurring in flood-prone areas. Clearly, increases in the intensity and frequency of storms associated with climate change are a major risk to these assets and the welfare of vulnerable communities.

Despite this very real threat, current flood maps in Jamaica are out of date, little effort has been put towards educating people about flood safety and adaptive capacity in flood-prone communities is low. This project, implemented by the University of the West Indies (UWI), Mona, has addressed these deficiencies.

The project focused on the vulnerable communities of the Yallahs river, as well as communities around the Orange River watershed in Negril. It created improved flood models for these two watersheds, showing the extent of flooding and flood water depth. It also used information from past extreme rainfall events to create maps which illustrate future flood risk. The goal was to model extreme events and create five, ten and twenty-five-year flood inundation maps for both present and future climate projections.

This project has already had major success. Data on historical record of floods and frequency of flooding in Jamaica has been updated, compiled and visualized. Maps of the island showing the relation of flooding with topography, land-use and river networks as well as to the 30-year mean annual rainfall have been created. Hydrological models and flood hazard maps have been made or are in production for the Yallahs and Orange River watersheds. Community awareness for impacts of climate change to flooding in the Yallahs River watershed has been increased, and surveys been conducted for the Orange River. 5, 10, 25, 50, 100 year flood risk maps have been created for both areas.

Outputs from this project are fed into a map-based decision-making tool that assists policy-makers in creating or revising effective flood mitigation measures, evacuation strategies and national disaster risk management plans. Additionally, it helps determine the adaptation measures that can be adopted by communities to respond to increasing flood risk, and protect those most vulnerable.

Outputs include:

• A policy brief on Flood Risk in Jamaica : Recent Damage and Loss due to tropical cyclones in Jamaica

• An initial survey on Knowledge, Attitudes and Practices Study on the Effects of Climate Change in the Upper Yallahs Watershed

• Further documents include a newsletter summarizing the project and workshops, posters and presentations on Assessment of future flood risk using hydrodynamic models, Simulations of Hydrological Extremes in Jamaica and Flood Hazards in Jamaica with special emphasis on The Yallahs River Watershed.

• A comprehensive project presentation prepared for a CDKN webinar can be found here.

Image copyright: Sebastian Kratzer