2011年-世界发展银行全球_Towards_a_Strategic_Analysis_of_Water_Resources_Investments_in_Kenya___Hydrological_Economic_and_Institutional_Assessment_for_Storage_Development_152页_5mb

Summary of "Towards a Strategic Analysis of Water Resources Investments in Kenya"

Core Content

This document is a strategic analysis of water resources investments in Kenya, focusing on hydrological, economic, and institutional aspects of storage development. It was prepared by the World Bank in 2011 and aims to support Kenya's development goals, particularly under Vision 2030. The report outlines the challenges of water scarcity, the importance of storage development, and provides a framework for prioritizing investments in key water-stressed areas.

Main Views and Key Information

Country Context

• Kenya has a low freshwater endowment of 526 m³ per capita per year, placing it among the bottom eight percent of countries globally.
• Over 80% of Kenya is classified as arid or semi-arid land (ASALs), where water availability is a major constraint on economic development.
• The country faces high hydrologic variability, leading to economic losses due to frequent droughts and floods.
• Water is a critical factor for economic production and human development.
• Water security is essential for Nairobi and Mombasa, the country's economic hubs, and for ASALs and western provinces, which are highly water-stressed.

Study Objectives and Methodology

• The study aimed to prioritize water storage investments to reduce water stress in economically important areas.
• It used a reliability-based approach to assess water resources, considering the impact of hydrologic variability.
• The methodology included:
  • Assessment of sectoral water requirements
  • Water resources assessment
  • Hydrology analysis
  • Water balance assessment to identify water-stressed sub-catchments
  • Identification of potential surface water supply options
  • Engineering analysis of dam sites
  • Economic and financial evaluation
  • Environmental and social impact assessment
  • Institutional analysis

Water Storage Investments

• 225 dams were initially considered based on the 1992 National Water Master Plan.
• A preliminary screening reduced the number to 73 candidate dams for further analysis.
• The screening criteria included:
  • Proximity to water-stressed areas
  • Reliable yield from the storage
  • Estimated benefits for various sectors (urban, livestock, irrigation)
  • Capital costs and associated infrastructure
• Surface water storage is emphasized as a key solution to increase water supply reliability and resilience.
• 80% and 90% reliability were used as benchmarks for surface water yield, with 7.6 BCM and 3.5 BCM of water available annually at these levels, respectively.

Water Requirements

• Water requirements were estimated for:
  • Irrigated agriculture
  • Domestic use
  • Industry and commerce
  • Power generation
  • Environment, wildlife, and tourism
• The study updated water requirements for 2010 and 2030, considering national development plans.
• Water stress is identified in 31% of sub-catchments in 2010 and is projected to increase to 43% by 2030.

Water Resources Assessment

• Kenya's renewable surface water is estimated at 29.9 BCM/year, and renewable groundwater at 0.62 BCM/year.
• Catchment degradation is a major issue, contributing to sedimentation and reduced storage capacity.
• Environmental flow considerations are integrated into the analysis to ensure ecological sustainability.

Economic and Financial Analysis

• The study evaluates the cost-benefit analysis of potential storage investments.
• It highlights the economic importance of water storage, especially in Nairobi, the Coast, and Western Kenya.
• Small-scale irrigation is identified as a viable option to improve water use efficiency and support agricultural growth.

Institutional and Policy Framework

• Kenya's Water Act 2002 outlines the roles and responsibilities of various institutions.
• Key institutions include:
  • Ministry of Water and Irrigation (MWI)
  • Water Resources Management Authority (WRMA)
  • Water Services Regulatory Board (WASREB)
  • National Irrigation Board (NIB)
  • Kenya Electricity Generating Company (KenGen)
• Institutional coordination is essential for effective water resources management.
• Institutional capacity building is recommended to support sustainable development.

Recommendations and Next Steps

• Environmental and Social Impact Assessments (ESIA) should be conducted for all proposed storage projects.
• Investment planning should focus on priority areas with the highest water stress and potential economic returns.
• Strengthened water resources management and development capacity is necessary to support long-term planning and implementation.
• The World Bank is encouraged to play a key role in financing and supporting water storage and infrastructure development.
• Integrated catchment management and basin-level planning are critical for sustainable water use and reducing environmental degradation.

Conclusion

Water storage development is essential for enhancing water supply reliability, mitigating the impacts of hydrologic variability, and supporting Kenya's economic growth and poverty reduction goals. The report identifies 30 storage investments for detailed study, with a focus on Nairobi, the Coast, and Western Kenya. These investments are expected to improve irrigation, urban water supply, and flood management, while also contributing to environmental sustainability and institutional capacity building.