Green hydropower: a new assessment procedure for river management

Abstract

Hydropower is the most important renewable electricity source worldwide. It shows clear advantages for the global CO 2 balance but creates serious ecological impacts on a local scale. As a consequence, concern for the conservation of natural river ecosystems is growing within society and more people are willing to pay extra for so-called 'green electricity'. The definition of 'green', however, is not straightforward and customers cannot directly examine the quality of electricity products. Therefore, credible certification of high ecological standards is essential for successful green electricity marketing.In this paper we introduce a new assessment procedure for evaluating environmentally compatible hydropower production. This so-called 'Green Hydro' concept was developed in the context of a multidisciplinary case study on a 400 MW hydropower scheme in the Southern Alps of Switzerland. The concept guarantees both general standards for different schemes operating in different types of watersheds and flexibility for local particularities. We developed an environmental management matrix that considers basic criteria and eco-investments and covers five environmental areas of concern (i.e. hydrological character, connectivity, morphology, landscape, and biological communities). The ecological perspective is complemented by five management domains (i.e. instream flow regimes, hydropeaking, reservoir and bedload management, and power plant structures). Applying assessment and modelling tools for the Green Hydro procedure showed that dynamic habitat models allowed quantification of the effects of different instream flow regulations at morphologically distinct sites. In this case, morphological restoration could be more beneficial than increasing the minimum flow.The first experience with the Green Hydro certification is encouraging. So far, 13 facilities have successfully passed the certification procedure. They produce a total of 186 GWh green electricity per year, which is sufficient for the supply of almost 40 000 households in Switzerland.

Modelling Tools to Analyze and Assess the Ecological Impact of Hydropower Dams

“…Finally, thirty-two articles were retained. In this work, we focus on four major questions: (1) what types of modelling approaches were applied for ecological impact assessment; (2) which input variables were used; (3) how were models validated; and (4) how can models be applied? Based on 32 articles, we listed all main input variables that were used; the type of model approaches; the model validation process and the output of the model.…”

“…Hydropower is a renewable and inexpensive source of energy [1][2][3] that already contributed to about 16% of the global electricity production in 2011 [4]. Dams have been continuously constructed for hydropower generation and other purposes [5][6][7].…”

Response of the riverine fish community to the construction and operation of a diversion hydropower plant in central Chile

“…pollution, damming, water diversion, changes in land use) and introduction of exotic species (Kingsford, 2000;Nunes-Godinho and Ferreira, 2000;Richter et al, 2003). Use of water for hydropower generation is widespread in many river systems and is the most important renewable electricity source worldwide (Bratrich et al, 2004). Negative effects of large dams associated with traditional hydropower facilities, such as habitat fragmentation, changes in fish reproductive environments and blocking of migration routes, are well known and have resulted in large-scale population and species decline (Pringle et al, 2000;Morita and Yamamoto, 2002;Richter et al, 2003;Young-Seuk et al, 2003;Phillips and Johnston, 2004).…”

“…Diversion-type hydropower plants have been considered ideal for ecologically fragile areas, if ecologically meaningful instream flows remain in the diverted river reach and fish migration across the dam is possible. Because they have no storage reservoir they are thought to cause a lower disturbance and impact to stream flow (sensu Bratrich et al, 2004).…”

Changes in water types under the regulated mode of water level in Three Gorges Reservoir, China

“…By the end of the 20th century, there were over 45 000 large dams in over 140 countries. China alone has built around 22 000 large dams, or close to half the world's total number (WCD, 2000;Bratrich et al, 2004). River damming shows profound societal and economic benefits including flood control, navigation, irrigation, drinking water supplies and hydropower production (Nilsson et al, 2005;Burke et al, 2009), but often create serious impacts on natural river ecosystems (Bratrich et al, 2004).…”