Evaluating Cost Trade-Offs between Hydropower and Fish Passage Mitigation

Abstract

To promote the sustainable management of hydropower, decision makers require information about cost trade-offs between the restoration of fish passage and hydropower production. We provide a systematic overview of the construction, operational, monitoring, and power loss costs associated with upstream and downstream fish passage measures in the European context. When comparing the total costs of upstream measures across different electricity price scenarios, nature-like solutions (67–88 EUR/kW) tend to cost less than technical solutions (201–287 EUR/kW) on average. Furthermore, nature-like fish passes incur fewer power losses and provide habitat in addition to facilitating fish passage, which presents a strong argument for supporting their development. When evaluating different cost categories of fish passage measures across different electricity price scenarios, construction (45–87%) accounts for the largest share compared to operation (0–1.2%) and power losses (11–54%). However, under a high electricity price scenario, power losses exceed construction costs for technical fish passes. Finally, there tends to be limited information on operational, power loss, and monitoring costs associated with passage measures. Thus, we recommend that policy makers standardize monitoring and reporting of hydraulic, structural, and biological parameters as well as costs in a more detailed manner.

Editorial: Green or red: Challenges for fish and freshwater biodiversity conservation related to hydropower

“…Ideally, such information should not only be assessed at the level of individual hydropower facilities, but instead include cumulative effects for entire river systems. Such a process requires the transparent incorporation of stakeholder interest and cost trade-offs: for example, between hydropower and fish-passage mitigation (Venus et al, 2020), as well as among biodiversity, food security, and hydropower (Ziv et al, 2012). Especially for large river systems, such as the Mekong and the Amazon, food security for people and power provision for economic development are key considerations that need to be integrated with conservation targets.…”

Costs of Ecological Mitigation at Hydropower Plants

“…Finally, local conditions such as the cost of materials and labour will also affect the magnitude of costs. Once the structure is built, there may be some recurring costs in the form of maintenance (Venus et al 2020b).…”

“…As nature-like fishpasses can also serve habitat functions including spawning or feeding habitats, investing in nature-like solutions may be the preferable conservation action . For an analysis of how different factors affect costs related to fish migration measures, see Venus et al (2020b). Downstream migration measures tend to be less technically advanced (Porcher and Larinier 2002).…”

“…An example of a fishfriendly turbine (Very-Low-Head) costs 500,000e per turbine (Dewitte et al 2020). Skimming walls cost approximately 3,000e per m 3 /s (Venus et al 2020b). Bypasses combined with other solutions range from 10,000e to 25,000e per m 3 /s (Ebel et al 2018).…”

Environmental threats and conservation implications for Atlantic salmon and brown trout during their critical freshwater phases of spawning, egg development and juvenile emergence

“…For upstream movements, especially the tailwater depth (pool below the barrier) plays a critical role in enabling passage. All this information is also key for designing suitable mitigation (Kemp, 2012; O’Hanley, 2011; Silva et al, 2018; Venus et al, 2020). Ideally for adult fish, the tailwater depth should be 1.25 times the height of the species to allow passage (Stuart, 1962).…”