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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

WCD recommendations on environmental flows

Strategic Priority #4 of the WCD recommendations stresses the importance of using environmental flows as a management approach to minimize and mitigate the downstream and upstream impacts of dam projects.

'Rivers, watersheds and aquatic ecosystems are the biological engines of the planet. They are the basis for life and the livelihoods of local communities. Dams transform landscapes and create risks of irreversible impacts. Understanding, protecting and restoring ecosystems at river basin level is essential to foster equitable human development and the welfare of all species. Options assessment and decision-making around river development prioritises the avoidance of impacts, followed by the minimisation and mitigation of harm to the health and integrity of the river system. Avoiding impacts through good site selection and project design is a priority. Releasing tailor-made environmental flows can help maintain downstream ecosystems and the communities that depend on them'.

Policy principle 4.5 proposes 'Large dams provide for releasing environmental flows to help maintain downstream ecosystem integrity and community livelihoods and are designed, modified and operated accordingly'. A six step process is outlined in Guideline 15.

• Step 1: Situation assessment
• Step 2: Specialist surveys and identification of ecosystem components
• Step 3: Developing predictive capacity on biophsyidcal responses to dam-related flow changes
• Step 4: Predicting social impacts of biophysical responses
• Step 5: Creating scenarios
• Step 6: Selection and implementation of one scenario

According to the WCD Guideline #14 on Baseline Ecosystem Studies:

'The effectiveness of mitigation, enhancement compensation and monitoring measures require better baseline knowledge and understanding of ecosystem. Baseline assessment inform both the national policy on maintaining rivers and requirements for environmental flows. …Baseline surveys should gather relevant information on:

• the life cycle of important fish species (especially migratory species);
• the distribution of habitat for threatened or endangered species;
• important areas for biodiversity; and
• key natural resources for riverine communities.

Detailed background and information on the various methods of environmental flow assessment are given in thematic review paper II.1 prepared for the WCD together with a series of contributing papers:

Berkamp, G., McCartney, M., Dugan, P., McNeely, J., Acreman, M. 2000. Dams, ecosystem functions and environmental restoration, Thematic Review II.1

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