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Dams and Development E-Paper Contents

p. -1 of 74 BACK | NEXT Home Page of Dams and Development Foreword I. Why an e-paper on dams and development? II. Assessing options III. Participatory processes IV. Social impacts V. Environmental impacts VI. Benefit distribution VII. Dam safety and sustainability VIII. Existing projects IX. Improving governance X. What other organizations say XI. ADB, Dams, and Development XII. References Contact Us

World Commission on Dams - assessment of cumulative impacts

WCD proposed that assessment of cumulative impacts should feature as a consideration throughout the planning cycle, from options assessment through to rehabilitation and upgrading of projects:

Options assessment:

'The range of options being examined at the outset will be broad and go beyond technical alternatives to consider relevant policy, programme and project alternatives. It should also consider:

• …the river basin context, cumulative impacts and interactive effects, including the interaction between surface and groundwater resources'; ….. (Policy Principle 2.2, p222)

Strategic impact assessment:

'Therefore, project proponents must assess the ecosystem consequences of the cumulative impact of dams, dam induced developments and other options along the full length of the river reaching as far as the delta, even where this extends into neighbouring provinces or countries'. (Policy Principle 4.1, p236)

'Strategic impact assessment during the options assessment stage should include independent and comprehensive assessment of ecosystem, social and health impacts and evaluation of any cumulative or inter-basin impacts. (Policy Principle 4.2, p227)

It [SEA] is a generic term that includes a range of planning tools for example, sectoral environmental assessments (EA), basin-wide EAs, regional EAs, and cumulative Eas'. (Guideline #4, p282).

Addressing existing dams;

'Because the economic life of a dam may span many generations, it is necessary to review the project operation periodically in light of the needs it is intended to meet, and the services it can provide. These periodic evaluations at intervals of 5 to 10 years should be comprehensive, integrated, cumulative and adaptive. Where dams are part of a larger river basin and regional development scheme, the evaluations should take into account basin-level evaluations of all project and programme components linked to the dam that affect the environment and society (see Strategic Priority 4)'. (Policy Principle 3.1, p227)

'Harmonising the licence expiry dates for all dams in a particular river basin may have benefits in some cases, for example a cascade sequence of dams where interactive effects and cumulative impacts are a consideration'. (Policy Principle 3.5, p232)

As a related measure, WCD proposed adoption of the precautionary approach:

'The precautionary approach requires States and water development proponents to exercise caution when information is uncertain, unreliable, or inadequate and when the negative impacts of actions on the environment, human livelihoods, or health are potentially irreversible. A precautionary approach entails improving the information base, performing risk analysis, establishing precautionary thresholds of unacceptable impacts and risk, and not taking actions with severe or irreversible impacts until adequate information is available or until the risk or irreversibility can be reduced, making outcomes more predictable'. (Guideline #5, p284)

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