Small Hydropower Plants' Proliferation Would Negatively Affect Local Herpetofauna

Abstract

Hydropower plants (HPPs) have a strong environmental impact on freshwater wetlands. Small diversion HPPs (SDHPPs) with 0.1–10 MW of installed power, redirect water from small mountainous rivers into several-kilometer-long tubes, disrupting complex dynamics of local aquatic food webs and their interactions with neighbor terrestrial food webs. It certainly affects local aquatic communities, but it is often neglected that two highly threatened vertebrate groups—amphibians and reptiles—which live in and around these wetlands, could be affected as well. In the Balkan peninsula, a part of Southeastern Europe, SDHPPs recently became very attractive and profitable for potential investors after they were proclaimed as eligible for subsidies from the national budget. As a result, in year 2020, the maximal projected number of SHPPs in the Balkans increased to 4,556. According to the literature data, ~28% of amphibian species in the Balkan Peninsula use small rivers and streams in the upper parts of watersheds as feeding, breeding and/or nursery habitats. Additionally, 38% of the total number of reptile species in Europe are registered in the hilly/mountainous areas of the peninsula, and 33% of these species strictly need humid habitats. The attempt of this mini-review is to present the facts which show that SHPPs and DSHPPs, in the way they are currently being installed, present harmful energy solution for the biodiversity of the mountain parts of Balkan peninsula, particularly for local amphibian and reptile populations which rely on lotic aquatic ecosystems and/or humid terrestrial habitats.

The Importance of Small Water Bodies’ Conservation for Maintaining Local Amphibian Diversity in the Western Balkans

“…"Run-of-river" small hydropower plants in the region are rapidly expanding and there are currently 81 active hydroelectric power plants, plus another 186 planned in Bosnia and Herzegovina [60]. They are eroding small mountain rivers-breeding sites for some amphibian species [13].…”

“…Small rivers are recently becoming increasingly threatened by the construction of small hydropower plants and the consequent devastation of the riverbeds [13].…”

“…Indeed, most of European amphibians require aquatic habitats, at least for reproduction [8][9][10]. This dependence on a freshwater environment for the completion of a life cycle increases the risk of local population declines in habitats subjected to intense anthropogenic alteration [11,12] which include not only the drying out of wetlands of all kinds, but also, for species which require running waters (lotic aquatic habitats), the construction of different kinds of hydroenergy power plants for the production of electric energy and/or water storage (see an example in [13]). Additionally, importing fish stock into originally fishless freshwater environments decreases the growth rate of local amphibian populations or causes their extinction [14].…”

Temporal dynamics in the physico-chemistry of a high-alpine stream network in the Swiss National Park

“…Changes in water availability in the Alps have already affected the tourist landscape, with human interventions being continuously necessary to sustain economic stability (Zarrineh et al 2020). Other changes have occurred with respect to hydropower generation (e. g. increases in small head hydropower facilities, Lange et al 2018;Crnobrnja-Isailovic et al 2021), and the ongoing switch to alternative energy sources. Lastly, water-quality monitoring provides baseline environmental information in understanding changes in the ecology of water resources such as aquatic biodiversity (Jacobsen et al 2014).…”

Eco-Energetic Efficiency – Comparative Analysis of Steam Power Plants Versus Micro Hydropower Plants

“…Hydroenergy represents the type of renewable energy used most frequently, as micro hydropower plants have a lower carbon footprint, often being promoted as an answer to the significant reduction of greenhouse gas emissions and implicitly to the mitigation of the effects of climate changes [2]. Nevertheless, the micro hydropower plants' negative effects on the environment must not be underestimated even if they are promoted as energy sources with low impact on the environment [3,4]. Although the micro hydropower plants have a small capacity, they affect the natural flow of rivers which, normally, provide large quantity of water resulted from the melting of snow during spring and summer and low quantities of water determined by low rainfall during winter and autumn, thus the mountain rivers being given a unique dynamic character.…”