Unit for Sustainable Development and Environment Organization of American States

1. Unit for Sustainable Development and Environment Organization of American States Managing Water Resources in a Changing Climate in the Caribbean Region Jan C. Vermeiren Principal Specialist

2. Multiple Challenges Present Day Challenges: Securing reliable supply in the face of rising demand and reduction in the resource base. Future Challenges: Planning for potential impact of climate change on the demand and on the resource base.

3. Present Day Challenges: Supply and Demand Caribbean • In several countries, annual per capita freshwater availability falls far below 1000 cubic meter, commonly used to measure scarcity. • Deforestation in upper watersheds reduces water retention and base flow. • Existing water storage capacity is inadequate. • Water distribution systems are overstretched. • Export agriculture depends increasingly on irrigation. • Growth in population, and especially in tourism, drives increasing demand for water.

4. Climate Change: A Source of Uncertainty • Traditional water resources management consists in keeping available supplies and demands in balance. • Under a changed climate, it is unwise to rely on historical data as sole guide to the future. • Use Global Climate models (GCm) to develop climate change scenarios that outline possible changes in key climate variables (temperature, rainfall, sea-level rise). • Use Impact Assessment to determine/quantify positive or negative impacts of CC on population, infrastructure, socio-economic activities and ecosystems.

5. 20 1000 950 900 850 15 800 emissions (GtC/yr) 750 700 10 CO concentration (ppm) 2 650 600 550 2 Anthropogenic CO 5 500 450 400 0 350 2000 2050 2100 2150 2200 2250 2300 2350 2000 2050 2100 2150 2200 2250 2300 2350 750 ppm stabilisation 550 ppm stabilisation Unmitigated emissions Emissions and concentrations of CO2 from unmitigated and stabilising emission scenarios

6. Temperature riseAnnual average, from the present day to the 2080s

7. Change in precipitationAnnual average, from the present day to the 2080s

8. The rise in sea-level from unmitigated and stabilising emission scenarios 1.2 1.0 0.8 0.6 Sea-level rise (m) 0.4 0.2 0.0 1900 2000 2100 2200 750 ppm stabilisation 550 ppm stabilisation Unmitigated emissions

9. Climate Change Induced Challenges • Changes in the hydrological cycle will affect rainfall patterns, which may result in longer and/or more frequent dry periods, alternated by periods of more intense rainfall, with negative consequences for urban and agricultural water supply, and hydropower generation. • Sea-level rise may cause salt-water intrusion in aquifers, in marshlands and areas of brackish water that feed desalinization plants, and in rivermouths • Rise in temperature will increase evapo-transpiration and increase urban and agricultural consumption.

10. Recent Efforts in Addressing Climate Change and Water Resources Management • UNEP/GEF Country Study on CC Impact on Water Resources (1997) in Antigua & Barbuda; unable to quantify impact on water supply due to lack of climate scenario data. • National Communications under the UNFCCC identified possible threats to water supply from CC. • CPACC Country Policy papers identify need for detailed vulnerability assessment (VA) of water resources sector. • UNEP/UNDP/CEHI-GEF project on Integrating Management of Watersheds and Coastal Areas in Caribbean SIDS. • IMPACC, the successor project to CPACC, will include waters resources VA and adaptation measures. .

11. Integrating Management of Watersheds and Coastal Areas in Caribbean SIDS • GEF Block B Grant -- February 2000 to December 2001 • Implementing Agencies -- UNDP and UNEP • Executing Agencies -- UNEP/RCU and CEHI • Steering Committee -- CARICOM, CEHI, OAS, UNDP. UNEP • Participating countries: CARICOM member nations plus Haiti, the Dominican Republic, and Cuba. • Assists participating countries in improving watershed and coastal zone management practices in support of sustainable development.

12. Integrating Management of Watersheds and Coastal Areas in Caribbean SIDS STATUS: • Currently reviewing national reports on critical issues. • Regional meeting in Jamaica (February 2001). • Regional synthesis being developed. • Full project brief will be submitted to the GEF for consideration in October 2001.

13. Adaptation to CC in the Water Sector Apply the Precautionary Principle • Reduce losses in distribution networks. • Promote conservation and recycling of wastewater. • Rehabilitate watersheds. • Construct additional water storage capacity. • Improve climate monitoring and forecasting for reservoir and intake management. • Apply true water pricing, creating incentives for conservation

14. Unit for Sustainable Development and Environment CONTACT INFORMATION Jan C. Vermeiren Principal Specialist Tel: (202) 458-3006 Fax: (202) 458-3560 E-mail: jvermeiren@oas.org