Vulnerability and Adaptation in the Mara River Basin
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TECHNICAL REPORT VULNERABILITY AND ADAPTATION IN THE MARA RIVER BASIN May 2019 This document was produced for review by the United States Agency for International Development. It was prepared by Chemonics International for the Climate Change Adaptation Thought Leadership and Assessments (ATLAS) Task Order No. AID-OAA-I-14-00013, under the Restoring the Environment through Prosperity, Livelihoods, and Conserving Ecosystems (REPLACE) IDIQ. Chemonics contact: Chris Perine, Chief of Party ([email protected]) Chemonics International Inc. 1717 H Street NW Washington, DC 20006 ATLAS reports and other products are available on the Climatelinks website: https://www.climatelinks.org/projects/atlas Cover Photo: Tea plantation near Bomet, Kenya; photo by Fernanda Zermoglio, 2018 VULNERABILITY AND ADAPTATION IN THE MARA RIVER BASIN May 2019 Prepared for: United States Agency for International Development Adaptation Thought Leadership and Assessments (ATLAS) Prepared by: Fernanda Zermoglio, Owen Scott and Mohammed Said, Chemonics International Inc. This report is made possible by the support of the American people through the United States Agency for International Development (USAID). The contents of this report are the sole responsibility of the author or authors and do not necessarily reflect the views of USAID or the United States government. CONTENTS LIST OF FIGURES AND TABLES ····································································· II ACRONYMS ·································································································· V EXECUTIVE SUMMARY ·················································································· 1 Overview ......................................................................................................................... 1 Climate Risks and Water Availability .................................................................... 1 What Makes the Basin’s Inhabitants Vulnerable?................................................. 2 Methods .......................................................................................................................... 3 Recommendations to Address the Risks and Impacts of Climate Change in the Mara River Basin ................................................................................................. 4 Strengthening Governance and Institutions.......................................................... 4 Improving Information .......................................................................................... 4 Piloting Interventions ............................................................................................ 5 INTRODUCTION ···························································································· 6 Objectives of this Assessment ......................................................................................... 7 OVERVIEW OF THE MARA RIVER BASIN ························································· 8 Biogeographic Characteristics and Trends ...................................................................... 9 Socioeconomic Characteristics and Trends ................................................................... 10 Water Resources ........................................................................................................... 11 Institutional Management of Water Resources .............................................................. 12 National Policy ................................................................................................... 12 Management of Water Resources in Tanzania .................................................. 15 Management of Water Resources in Kenya ....................................................... 16 VULNERABILITY ··························································································19 Methods ........................................................................................................................ 19 Detailed Methodological Approach for Individual Variable Calculations .............. 20 Exposure of the Basin to Climate Risks ......................................................................... 22 Climatology and Climate Variability .................................................................... 23 Historical Occurrence of Extreme Events that Impact the Basin ......................... 28 Climate projections ............................................................................................ 29 Other Pressures Impacting Climate Sensitivities of the Mara River Basin .......... 39 Summary ....................................................................................................................... 48 OPPORTUNITIES AND RECOMMENDATIONS ··················································50 REFERENCES ······························································································54 ANNEX 1: CASE STUDY – NYANGORES SUBCATCHMENT ······························57 ANNEX 2: CASE STUDY – MARA WETLANDS ·················································69 ANNEX 3: DATA LIST OF SPATIAL INFORMATION COMPILED AND UTILIZED FOR THIS ASSESMENT ·························································86 ANNEX 4: FIELD DATA COLLECTION ·····························································87 Nyangores WRUA Community Meeting – Activity Output .............................................. 87 Mara North WRUA Community Meeting – Activity Output.............................................. 91 VULNERABILITY AND ADAPTATION IN THE MARA RIVER BASIN | i LIST OF FIGURES AND TABLES Figure 1: The Mara River Basin ................................................................................................. 8 Figure 2: Hierarchy of water institutions under Kenya’s 2016 Water Act....................................16 Figure 3: Effects of ENSO in Africa ...........................................................................................23 Figure 4: Average annual rainfall in the Kenya and Tanzania areas of the Mara River Basin ....24 Figure 5. Average annual rainfall distribution in the Mara River Basin .......................................24 Figure 6. Average annual maximum temperature in the Mara River Basin, 1991–2015 .............25 Figure 7. Average annual minimum temperature in the Mara River Basin, 1991–2015 ..............25 Figure 8. Average monthly rainfall and average temperature in the Mara River Basin, 1991– 2015 ..........................................................................................................................................26 Figure 9. Trends of annual minimum temperature for the Mara River Basin for Kenya and Tanzania ...................................................................................................................................27 Figure 10. Trends of annual maximum temperature for the Mara River Basin for Kenya and Tanzania ...................................................................................................................................27 Figure 11. Disasters in Bomet, Narok and Nakuru counties in Kenya, 1997–2017 ....................28 Figure 12: Time series of temperature change relative to 1986–2005 averaged over land grid points in December–February and June–August .......................................................................31 Figure 13: Maps of temperature change in East Africa in December to February for 2016–2035 and 2046–2065 with respect to 1986–2005, according to the RCP 4.5 scenario .......................31 Figure 14: Mean projected temperature rise (°C) by season, time and scenario .......................32 Figure 15: Projected minimum temperature changes over the Lake Victoria Basin by the 2030s annually and in the long rains (March-April-May), long dry season (June-July-August- September) and short rains (October-November-December) ....................................................33 Figure 16: Projected minimum temperature changes over the Lake Victoria Basin by the 2050s annually and in the long rains (March-April-May), long dry season (June-July-August- September) and short rains (October-November-December) ....................................................33 Figure 17: Projected minimum temperature changes over the Lake Victoria Basin by the 2070s annually and in the long rains (March-April-May), long dry season (June-July-August- September) and short rains (October-November-December) ....................................................34 VULNERABILITY AND ADAPTATION IN THE MARA RIVER BASIN | ii Figure 18: Projected maximum temperature changes over the Lake Victoria Basin by the 2030s annually and in the long rains (March-April-May), long dry season (June-July-August- September) and short rains (October-November-December) ....................................................34 Figure 19: Projected maximum temperature changes over the Lake Victoria Basin by the 2050s annually and in the long rains (March-April-May), long dry season (June-July-August- September) and short rains (October-November-December) ....................................................35 Figure 20: Projected maximum temperature changes over the Lake Victoria Basin by the 2070s annually and in the long rains (March-April-May), long dry season (June-July-August- September) and short rains (October-November-December) ....................................................35 Figure 21: Projected rainfall changes over the Lake Victoria Basin by the 2030s annually and in the long rains (March-April-May),