Wednesday 2nd of july – 8:30
08:30
Nature Positive River Management and the Applicability of Biodiversity Offsets and Credits in Japan
AUTHORS
NAKAMURA Keigo, SUZUKI Toshihiro, MIYAGAWA Yukio
Japan
Short Abstract: In Japan, river restoration has been active since about 1990, and with the international trend toward nature-positive approaches and the advancement of quantitative assessment of river habitats, nature-positive river management focusing on quantitative habitat targets is about to be promoted. However, it is also true that many flood control works are carried out as safety measures in response to the intensification of disasters caused by climate change, and it is believed to be difficult to implement nature-positive river management for all rivers. In such cases, it is necessary to discuss the applicability of biodiversity offsets and biodiversity credits. When offsetting is carried out within a river basin, the creators of the biodiversity credits are likely to be local governments, companies, and farmers, and the river administrator will purchase the credits from these entities. In this paper, we will consider the content and issues that are expected to arise if these policies are applied in Japan.
08:50
Romanche Séchilienne : addressing flood risk management through environmental remediation
AUTHORS
BUISSON MORGANE, GRENIER MATHIEU, KUSS DAMIEN
France
Short Abstract: Located in the French Alps, the “Romanche Séchilienne” project, led by the Syndicat Mixte des Bassins Hydrauliques de l’Isère between 2006 and 2017, is an integrated river management project based on nature-based solutions (NbS). Its aim was to protect a region of 20,000 inhabitants from the risk of a 100-year flood of the Romanche River, while also addressing the potential overflow linked to the landslide risk of Séchilienne. In addition to hydraulic works, the project incorporated environmental remediations actions from its inception, focusing on areas severely degraded by the 19th-century hydroelectric industrialization and the expansion of urbanization in the Grenoble metropolitan area, as well as recreation facilities and landscape integration of the works. The project restored the natural floodplain of the Romanche on three sites upstream of the Vizille flood control system. The 2023 and 2024 floods confirmed the effectiveness of the system in these areas, which significantly contributed to sediment regulation through discharge mechanisms and logs trapping. The lateral dynamics initiated by the project helped recreate specific habitats typical of alpine rivers, classified as “priority habitats of community interest.” This project demonstrates how nature-based solutions can combine natural risk reduction with ecosystem restoration, thus enhancing ecological resilience to climate-related risks.
09:10
Restore and manage flooding on the Lower Dranse with nature-based solutions
AUTHORS
LEBLOIS Solange, WLODARCZYK Antoine, PEZET Florent, SAHUC Amélie, EVETTE André
France
Short Abstract: Session: The resilience of rivers to climate change: nature-based solutions and river management. How can we reduce the risk of flooding while preserving biodiversity? What solutions can be developed to restore the ecological functions of degraded areas? What strategies should be adopted to minimise greenhouse gas emissions and maximise the use of nature-based solutions? This case study presents and discusses the way in which the players involved tried to answer these questions in the context of the lower Dranses river restoration project – Haute-Savoie, France. The project builders created a synergy between environmental and risk management applying the GEMAPI. The use of nature-based solutions (NbS) also makes it possible to minimise the impact of the works and maximise the river’s resilience afterwards. It is notable that on such large and complexe projects, impact reduction is achieved as much through avoidance and the idea of working with the river as through the implementation of NbS. Due to the scale of this project, the effects of each strategy are difficult to discern and quantify. Detailed monitoring of all the blocks: ecology, morphology and hydraulics would be necessary. Works on the Lower Dranse restoration project lasted from 2022 to 2024.
09:30
Research and practice of climate change adaptation using ecosystem functions; the case of the Lake Imba watershed
AUTHORS
NISHIHIRO JUN, HIRANO Yuna, TAWA Kota, MATSUSHIMA Noe, OSAKA Maki
Japon
Short Abstract: Ecosystem management at the watershed scale is effective in responding to the increasing risks associated with ongoing climate change, such as floods, harmful algal blooms, and declining wildlife populations. Appropriate ecosystem management requires governance through information sharing and mutual cooperation between researchers, governments, citizen groups, residential people, and businesses. We have been conducting research on ecosystem functions in the watershed of Lake Imba, Japan. As a result, we were able to quantitatively clarify the functions of wetlands in the watershed, such as reducing flood risk, purifying water quality, and conserving biodiversity. We also verified that these functions can be strengthened through appropriate ecosystem management such as maintenance of wet condition of abandoned rice fields. In recent years, we have been working with many stakeholders to establish the organizations and funding mechanisms necessary for watershed governance. The lessons learned here will be useful for the management of river and lake watersheds in other regions of the world.
09:50
Assessment of Nature-based Solutions (NbS) for river and floodplain restoration under the EU Nature Restoration Law
AUTHORS
PUSCH Martin, WALDENBERGER Lisa, WAHEED Abdul, HAIMANN Marlene, PENNING Ellis, HABERSACK Helmut
Germany
Short Abstract: Implementation of the EU Nature Restoration Law (NRL) is hampered by the EU policy of aiming at the expansion of renewable energies, which also includes hydropower. In addition, re-establishing natural river dynamics needs space, so that current intense land uses near river channels need to be modified, where land owners and land users are often opposing to. Given these multiple conflicts of interests in river corridors, implementation of the EU Nature Restoration Law only seems realistic if an integrative approach is applied that considers other political goals, legal requirements, sectoral societal interests, and land user interests. Nature-based Solutions (NbS) appear well suited to overcome those obstacles for the implementation of the NRL. However, so far common river restoration measures have not systematically analyzed if they represent NbS or not. Only few of them have been categorized as either representing NbS or not. Hence, we analyzed 61 common river and floodplain restoration measures for their pertinence in fulfilling NbS criteria, applicability to several river types, and suitability to support 19 ecosystem services.