Protecting the downstream migration of salmon smolts from hydroelectric power plants with inclined racks and optimized bypass water discharge

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:284

Article

Tomanova, Sylvie^1,3  Courret, Dominique^1,3  Richard, Sylvain^2,3  Tedesco, Pablo A.⁴  Mataix, Vincent⁵  Frey, Aurelien⁶  Lagarrigue, Thierry⁶  Chatellier, Ludovic^3,7  Tetard, Stephane⁸ 

[1] Off Francais Biodiversite, Direct Rech & Appui Sci, Toulouse, France

[2] Off Francais Biodiversite, Serv Prevent Appui Prospect, Direct Police & Permis Chasser, Toulouse, France

[3] OFB IMFT PPRIME, Pole R&D Ecohydraul, Toulouse, France

[4] Univ Paul Sabatier, CNRS 5174, UPS, UMR EDB,IRD 253, Toulouse, France

[5] EDF CIH, Pole Energies Renouvelables, Toulouse, France

[6] ECOGEA, Muret, France

[7] Univ Poitiers, ENSMA, CNRS, Inst Pprime, Poitiers, France

[8] Lab Natl Hydraul & Environm, EDF R&D LNHE, Chatou, France

关键词: Hydropower plants;    Fish protection;    Downstream passage;    Efficient solution;    Fish passage solution;   

DOI  :  10.1016/j.jenvman.2021.112012

来源: Elsevier

【 摘 要 】

The sustained development of hydropower energy in the last century has caused important ecological impacts, promoting recent advances in efficient mitigation measures to be implemented in existing and future hydropower plants. Although upstream fish migration has been largely addressed with the development of fish-pass infrastructures, downstream passage solutions are often missing or inefficient, strengthening the need for their improvement and efficiency assessment. The efficiency of horizontally inclined (26 degrees) low bar spacing racks associated to a bypass was assessed using salmon smolts radiotelemetry along three successive hydropower plants (HPP) in the Ariege River (southern France). In average, nearly 90% of the smolts were successfully protected by the racks and rapidly guided to the bypass, within few minutes in most cases. Furthermore, we detected a significant positive influence of the bypass discharge (Q(bp%) expressed as the proportion of concurrent HPP discharge) on the probability of successful bypass passage, reaching 85% of successful passage with a Q(bp%) of only 3%, and more than 92% when the Q(bp%) exceeded 5%. The probability of bypass passage without hesitation (e.g. passage within the first 5 min) also increased with Q(bp%), and reached 90% with 5% of Q(bp%). Passage without hesitation was especially detected on the site having larger bypass entrances and transversal currents, providing better guidance into the bypass. High-efficiency results of inclined racks yielded with reduced Q(bp%) confirmed their relevance to mitigate some of the HPP ecological impacts, re-establishing safe downstream salmon migration with lower impact on energy production than older less efficient solutions.

【 授权许可】

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