PROFOR WORKING PAPER How Forests Enhance Resilience to Climate Change: THE CASE OF DRINKING WATER SUPPLY IN TEGUCIGALPA, HONDURAS 2 HOW FORESTS ENHANCE RESILIENCE TO CLIMATE CHANGE: THE CASE OF DRINKING WATER SUPPLY IN TEGUCIGALPA, HONDURAS Acknowledgments This study on the role of forests in enhancing landscape resilience to climate change is part of a larger multicountry project designed and led by Diji Chandrasekharan Behr (Sr. Natural Resource Management Specialist, World Bank) on the role of forests for enhancing resilience to climate change (www.profor.info/node/2032). The larger project aims to capture the role of forests in enhancing other sectors’ resilience to climate change. It examines how sustainable management of forests can contribute to strengthening social and physical resilience of systems in other sectors. Using forest and tree management as part of a broader strategy to enhance resilience to climate change could provide a low-cost option for local landscapes while also helping to balance production, livelihood, adaptation, and mitigation goals. The field data collection and preparation of the case study was led by Raffaele Vignola, Director of the Latin American Chair of Environmental Decisions at the Tropical Agricultural Research and Higher Education Center (CATIE). Other scientists included Amanda Procter, Angela Díaz Briones also from CATIE,Tim McDaniels from the University of British Columbia in Vancouver, Canada and colleagues at CIFOR—specifically, Serge Rafanoharana, Bruno Locatelli, and Aaron J. M. Russell. The report submitted by the field team was formally reviewed by the Honduras Country Management Unit and comments were provided by Christian Peter (Lead Environmental Specialist). The report was finalized by Diji Chandrasekharan Behr with inputs from Maria Ana de Rijk (World Bank). The team is thankful for the financial support provided for this work by the Program on Forests (PROFOR) and the Trust Fund for Environmentally and Socially Sustainable Development (TFESSD). A multidonor partnership housed at the World Bank, PROFOR finances forest-related analysis and processes that support the following goals: improving people’s livelihoods through better management of forests and trees; enhancing forest law enforcement and governance; financing sustainable forest management; and coordinating forest policy across sectors. In 2012, PROFOR’s donors included the European Union, Finland, Germany, Italy, Japan, the Netherlands, Switzerland, the United Kingdom, and the World Bank. Learn more at www.profor.info. Disclaimer: The findings, interpretations, and conclusions expressed in this paper do not necessarily reflect the views of the Executive Directors of the World Bank, the governments they represent, or the donors of PROFOR and TFESSD. The World Bank does not guarantee the accuracy of the data included in this work. The boundaries, colors, denominations, and other information shown on any map in this work do not imply any judgment on the part of the World Bank concerning the legal status of any territory or the endorsement or acceptance of such boundaries. Suggested Citation: Vignola, Raffaele and Amanda Procter, Angela Díaz Briones, Tim McDaniels, Bruno Locatelli, Serge Rafanoharana and Diji Chandrasekharan Behr. 2015. How Forests Enhance Resilience to Climate Change: The case of drinking water supply in Tegucigalpa, Honduras. Working Paper. Washington DC: Program on Forests (PROFOR). For a full list of publications please contact: Program on Forests (PROFOR) 1818 H Street, NW Washington, DC 20433, USA [email protected] www.profor.info/knowledge PROFOR is a multi-donor partnership supported by the European Commission, Finland, Germany, Italy, Japan, the Netherlands, Switzerland, the United Kingdom and the World Bank Group. HOW FORESTS ENHANCE RESILIENCE TO CLIMATE CHANGE: THE CASE OF DRINKING WATER SUPPLY IN TEGUCIGALPA, HONDURAS 3 Executive Summary Climate change has potentially dire effects on livelihoods and human well-being through disruptions to agriculture, food, water, and biomass-based energy supply systems and through changes in disease vector dynamics. It is of particular concern to developing countries, as they have limited resources for large-scale adaptation efforts to buffer people from the impacts. Honduras is considered one of the most vulnerable countries to climate change in Latin America. It ranks third on a global climate risk index, which uses exposure and vulnerability to extreme events for the period 1991–2010 as a proxy. In addition to extreme events, future climate scenarios forecast an increase in water scarcity in Honduras due to climate change and increased variability in rainfall. A national study on future climate change scenarios suggests a 5 percent decrease in annual rainfall by 2020—particularly along the northwest-southeast corridor. By 2050, a 20–25 percent decrease in precipitation is projected for most parts of the country between June and August, with deficits greater than 30 percent for most areas during July and August, especially in the departments of western Honduras. At the same time, mean temperatures are expected to increase in western and southern regions of the country, aggravating the situation, as the low rainfall period that normally occurs during the rainy season will become longer, hotter, and drier. Access to water is already a constraint in many parts of Honduras. The expected changes in climate will put crops and water access for human consumption at even greater risk. Ecosystem-based adaptation (EBA) is an approach that seeks to lower the impacts of climate change on human systems by strengthening ecological systems. This type of adaptation attempts to address both past environmental degradation and climate change–induced environmental change to improve outcomes for human systems. This study examines the potential benefit of using an EBA strategy involving forests as part of a larger strategy for enhancing the climate change resilience of the reservoir systems that provide drinking water to Tegucigalpa, Honduras. This report, one in a series of studies, explores how forests, through the provision of ecosystem services, contribute to other sectors’ adaptation to climate change.1 The case study in Honduras seeks to integrate climate change and ecosystem services modeling at the watershed scale with an economic analysis of the impacts of watershed management policies on water quality and quantity under high and low climate change scenarios. The first objective of the case study is to inform decision makers in government and development organizations of the potential economic benefits of including EBA measures alongside infrastructural investments to enhance the resilience of the water storage system in the watershed, given the projected impacts of climate change. The second objective, which is tied to the broader set of studies, is to explore an approach of generating the needed evidence, given the challenges of obtaining data that would facilitate optimal decision making. Given the scope of this project, several different research methods were used to generate data on future climate, governance regime, the economic impact of management options, and current and future system vulnerability. The study area is the Guacerique watershed. The watershed is in a mountainous region with a mean altitude of 1,450m, and over 56 percent of the land area has slopes greater than 15 percent. Steep slopes combined with a shallow soil layer and soil structure, drainage, moisture levels, and rockiness mean the watershed is best suited to forested land uses. 1. For more information on the set of case studies, see www.profor.info/node/2032. 4 HOW FORESTS ENHANCE RESILIENCE TO CLIMATE CHANGE: THE CASE OF DRINKING WATER SUPPLY IN TEGUCIGALPA, HONDURAS The Guacerique watershed has a current population of 8,853, and the annual growth rate is estimated to be 2.4 percent.2 The primary livelihoods in the area include subsistence and small-scale commercial agriculture (primarily vegetables), subsistence cattle farming, and forestry. This highlights the close relationship between local livelihoods, forests, and ecosystem services. The Guacerique watershed is divided between two municipalities. Most of it (166.82 km2) falls within the boundaries of Tegucigalpa, while 25 km2 of the watershed is under the jurisdiction of the municipality of Lepaterique. Two of the four streams that come together to form the Guacerique River (Guajire-Mateo and Quiscamote) have their headwaters in Lepaterique, making it an important player in land and resource management in the watershed. In 1973 the government of Honduras declared the Guacerique watershed a protected public forest. Despite this, the watershed has undergone significant land use changes—deforestation and conversion to agriculture and human settlement. The two main drivers of land use change are small-scale agriculture and human settlement. Small-scale farmers live throughout the watershed, including within the boundaries of the Yerba Buena Biological Reserve. Drinking water for Tegucigalpa mainly comes from surface waters, and the primary sources are the Guacerique, Grande, Sabacuante, and Tatumbla Rivers, which are part of the upper Choluteca River basin. Additional water is provided to the system from springs in the La Tigra Nature Reserve. Reservoirs are used because the river volumes fluctuate greatly over the course of the year between the wet and dry seasons. Water shortages primarily occur because of insufficient