Evidence-based indicator approach to guide preliminary environmental impact assessments of hydropower development

• Published in: Journal of environmental management 2020-07, Vol.265 (C), p.110489-110489, Article 110489
• Main Authors: McManamay, Ryan A., Parish, Esther S., DeRolph, Christopher R., Witt, Adam M., Graf, William L., Burtner, Alicia
• Format: Article
• Language: English
• Subjects: Dams; Eco-evidence; Ecosystem; Environmental indicators; River; Rivers; Streams; Sustainability protocol
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.110489

Global expansion of hydropower resources has increased in recent years to meet growing energy demands and fill worldwide gaps in electricity supply. However, hydropower induces significant environmental impacts on river ecosystems - impacts that are addressed through environmental impact assessment (EIA) processes. The need for effective EIA processes is increasing as environmental regulations are either stressed in developing countries undertaking rapid expansion of hydropower capacity or time- and resource-intensive in developed countries. Part of the challenge in implementing EIAs lies in reaching a consensus among stakeholders regarding the most important environmental factors as the focus of impact studies. To help address this gap, we developed a weight-of-evidence approach (and toolkit) as a preliminary and coarse assessment of the most relevant impacts of hydropower on primary components of the river ecosystem, as identified using river function indicators. Through a science-based questionnaire and predictive model, users identify which environmental indicators may be impacted during hydropower development as well as those indicators that have the highest levels of uncertainty and require further investigation. Furthermore, an assessment tool visualizes inter-dependent indicator relationships, which help formulate hypotheses about causal relationships explored through environmental studies. We apply these tools to four existing hydropower projects and one hypothetical new hydropower project of varying sizes and environmental contexts. We observed consistencies between the output of our tools and the Federal Energy Regulatory Commission licensing process (inclusive of EIAs) but also important differences arising from holistic scientific evaluations (our toolkit) versus regulatory policies. The tools presented herein are aimed at increasing the efficiency of the EIA processes that engender environmental studies without loss of rigor or transparency of rationale necessary for understanding, considering, and mitigating the environmental consequences of hydropower. •Global hydropower expansion requires effective environmental impact assessment.•We design a prototype toolkit to increase the effectiveness and efficiency of EIAs.•Indicators determine relevant hydropower impacts on rivers via weight of evidence.•Tools predict impacts with a few attributes and examine linkages among indicators.•We apply the tools to a series of case studies to show the utili