1.1 Introduction

Policies are crucial in determining and improving the state of our environment. Policies set goals (including targets, indicators and time frames) while policy instruments are the specific means or measures to translate the policy intent into action (Jacob et al. 2019). In discussions on the sustainability of hydropower production, knowledge of the currently existing regulations at different levels is indispensable (Bunge et al. 2003) in understanding the framework conditions for decisions on impact-mitigating measures. Hydropower plants play an important role in the production of renewable energy and in the reduction of CO2 emissions. At the same time, hydropower can have a range of negative effects on the flow of rivers, the habitats of fish and aquatic organisms, as well as on fauna and flora species that depend on river and lake ecosystems for their survival (EC 2018). Therefore, hydropower is at the cross-road of goals and instruments of different policy fields on energy/climate, water and nature. All these different policies need to be taken into account in a balanced way considering synergies and trade-offs when planning and implementing mitigation actions for hydropower.

In the European Union (EU), several EU and national policies set ecological and environmental requirements on hydropower plants. These include in particular policies for the protection of nature and water resources. Further, the planning and operation of European hydropower plants takes place in the framework of policies that promote and support the production of renewable energy. Illustrated with examples, this chapter introduces the policy and legislative framing for hydropower in the EU and in selected European countries as well as its implications for the planning of mitigation measures and the realisation of more sustainable hydropower.

1.2 Policy Framework for Hydropower Mitigation

This section reviews key EU and national policies with requirements for mitigating the ecological impacts of hydropower, illustrated with examples from a policy survey of eight European countries (Kampa et al. 2017). In addition to EU policy objectives, national policies specify and operationalise the policy framework in which hydropower operators need to mitigate the impacts of hydropower production. Policy requirements need to be considered in the decision-making processes of hydropower operators and authorities, both in the relicensing process of existing hydropower plants (HPPs) and the licensing of new HPPs.

The main policies that are relevant to the planning and operation of hydropower plants address renewable energy and climate change, water resource protection, water resource infrastructure, nature and biodiversity protection, fisheries, invasive alien species and project impact assessment (Fig. 1.1).

Fig. 1.1
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Broad categories of European and national policies relevant to the operation and planning of hydropower plants

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Due to the focus on EU policies and national policies in European countries, global processes are not addressed in this section. It is noted though that a number of international agreements are relevant to sustainable hydropower production, such as the 2030 Agenda for Sustainable Development, the Convention on Migratory Species (CMS), the Convention on Biological Diversity (CBD) and the United Nations Framework Convention on Climate Change (UNFCCC).

1.2.1 European Policies

The planning, operation and mitigation of impacts of hydropower plants need to be aligned with the key objectives of EU policy on water, energy as well as biodiversity protection. The recently adopted European Green Deal (EC 2019) sets a framework for aligning the objectives of these different policies, in view of the Green Deal aims for a “climate neutral” Europe and for enhanced protection of European ecosystems and biodiversity.

As hydropower production takes place in the aquatic environment, the objectives of the EU Water Framework Directive (WFD) need to be a primary consideration. Since its adoption in 2000, the WFD has been a strong driver for restoring aquatic ecosystems and river continuity. The WFD is the key policy taken into account in European countries when modifying the licensing procedures for new hydropower plants and when revising licenses of existing plants. The Directive’s main aim (Article 4(1)) is to prevent deterioration of status and achieve good status of all EU waters, including surface and groundwater, by 2015 (at the latest by 2027). For surface waters, the Directive distinguishes between good ecological and good chemical status. Ecological status is “good” when the values for biological quality elements of surface waters (fish, benthic invertebrates, aquatic flora, phytoplankton) deviate only slightly from undisturbed conditions. Hydromorphological and physico-chemical parameters are supporting elements to the biological quality elements for classifying the status of water bodies.

A river basin management plan has to be established for each river basin district defined under the WFD in a cyclical process every six years, which involves the development of a programme of measures to tackle significant pressures on water bodies, including those from hydropower activities in the form of barriers on rivers, hydrological alterations and abstractions.

So far, progress in achieving the WFD aim of good status has been slow, with only around 40% of surface waters being in good ecological status or potential in the second river basin management plans of 2015 (EEA 2018). Significant pressures from hydropower production affect approximately 9000 surface water bodies (6% of total surface water bodies) (EEA 2021). In addition, hydropower is the most common reason for designating heavily modified water bodies according to Article 4(3) of the WFD applicable to approximately 6000 water bodies (half of these water bodies being in Norway) (EEA 2021). Water bodies can be designated as heavily modified and have lower environmental objectives, when it is not viable to remove physical modifications such as a dam and particular water uses and public interests stand in the way of extensive restoration of the water bodies in question.

Concerning the development of new hydropower plants or modifications to existing plants in Europe, Article 4(7) of the WFD has to be taken into account. Article 4(7) makes new infrastructure projects possible, only if certain strict conditions are met, i.e. there are no significantly better environmental options, the benefits of the new infrastructure outweigh the benefits of achieving the WFD environmental objectives and all practicable mitigation measures are taken to address the adverse impact on the status of the water body.

Next to water policy, EU policy on biodiversity and nature protection is another major layer in the policy framework of hydropower production in Europe. At locations affected by hydropower, Natura 2000 site provisions for the protection of certain species and habitats need to be taken into account. Furthermore, any plan or project that could affect a Natura 2000 site should be subject to an assessment procedure to study these effects in detail, based on Article 6(3) of the Habitats Directive. This is relevant for new hydropower projects and for upgrades or modernizations of existing hydropower plants. Except for the provisions within the Natura 2000 network, the Habitats Directive and the Birds Directive concern the protection of certain species across their entire natural range within the EU, i.e. also outside Natura 2000 sites. These provisions need to be taken into account by operators of hydropower plants, especially on rivers harbouring migratory fish species that are listed in Annex IV of the Habitats Directive, such as the European sea sturgeon (EC 2018).

Progress in achieving EU nature protection objectives has to this day been slow, as only 15% of habitat assessments identified good conservation status between 2013 and 2018. Key pressures on European habitats and species include modifications to hydrological flow, physical alterations including barriers and hydropower installations (EEA 2020).

The new EU Biodiversity Strategy adopted in 2020 includes targets for restoring freshwater ecosystems that are also relevant to activities of hydropower production. The Biodiversity Strategy targets include the restoration of at least 25,000 km of rivers into free-flowing rivers by 2030 and the restoration of degraded ecosystems, like floodplains and wetlands. In addition, water abstraction and impoundment permits should be reviewed to implement ecological flows in order to achieve good status or potential of all surface waters and good status of all groundwater by 2027 in line with the WFD (EC 2020a).

Equally important to the EU water and nature protection policy framework is the EU policy agenda for renewable energy and climate change mitigation and adaptation. Energy production from hydropower plays a key role for the EU to meet its energy needs and climate mitigation targets in the future. The revised EU Renewable Energy Directive (EU 2018) established a new binding target for the EU on the share of energy from renewables of at least 32% of the Union’s gross final consumption in 2030, with a clause for a possible upwards revision by 2023. EU countries are required to draft 10-year National Energy & Climate Plans for 2021–2030, outlining how they will meet the new 2030 targets for renewable energy and energy efficiency.

There are significant differences between EU countries in terms of the extent to which hydropower is used in their renewable energy mix. This is highly influenced by geographic conditions, climate, precipitation patterns, the availability of affordable energy supply alternatives, as well as institutional capacities and technical competences (Kampa et al. 2017). To meet the EU renewable energy targets for 2030, some European countries will increase the use of hydropower for energy storage as well as energy production. For example, there are plans to expand hydropower pumped storage in Austria, the Baltic States and Portugal (IHA 2019).

Other EU policies which are relevant to the planning, operation and mitigation of impacts of hydropower plans are the EU Eel Regulation, the EU Regulation on Invasive Alien Species as well as the Strategic Environmental Assessment and Environmental Impact Assessment Directives (SEA/EIA).

The EU Eel Regulation (1100/2007) requires the establishment of measures for the recovery of the stock of the European eel (which is a species impacted by the presence of hydropower), the identification and definition of eel river basins and the set-up of Eel Management Plans to reduce anthropogenic mortalities and improve the escapement of the silver eel to the sea. Progress between 2007 and 2020 though on the achievements of the Eel Regulation has been limited. Overall biomass and escapement levels of silver eel have not yet significantly improved. Implementation of the Eel Regulation needs considerable improvement, especially when addressing non-fisheries related anthropogenic mortality, such as impacts from hydropower and dams (EC 2020b).

Also the EU regulation on Invasive Alien Species (in force since 2015) is relevant to hydropower plants, as the development of hydropower installations can create new connections between river systems, leading to the spread and dispersal of various aquatic organisms. In implementing this EU Regulation, Member States may include requirements in their hydropower authorisation procedures related to preventing the spread of alien species.

Finally, the Environmental Impact and Strategic Environmental Assessment Directives (EIA and SEA) are of particular relevance to the consenting of new projects in the hydropower sector. An environmental impact assessment is mandatory for dams and other installations that hold back or permanently store water, where a new or additional amount of water held back or stored exceeds 10 million cubic meters (Annex I projects of EIA Directive). Most installations for hydropower production in Europe though are Annex II projects under the EIA Directive, i.e. projects for which Member State authorities must first determine, in a procedure called “screening”, if projects are likely to have significant effects, taking into account certain criteria, before deciding on whether a project will be made subject to the EIA procedure. The SEA Directive is more relevant for planning hydropower at a larger and more strategic scale rather than at the level of individual hydropower projects. A Strategic Environmental Assessment may be relevant for national plans and programmes on the development of hydropower including a more appropriate siting of future developments to avoid potential areas of conflict such as in Natura 2000 sites.

1.2.2 National Policies

National legislation defines the regulatory setting for planning and operating hydropower plants and for planning mitigation measures in a particular country. According to a recent review of hydropower-related national legislation by Kampa et al. (2017), the following are the main types of national acts that are used to regulate hydropower plants (HPP): water/water protection acts; water infrastructure acts; energy acts; nature protection acts; fishing/fisheries acts and environmental impact assessment acts.

National regulatory settings differ from country to country. The review by Kampa et al. (2017) carried out in the context of the FIThydro project gives a detailed account of the relevant acts in place in eight European countries: Norway, Sweden, France, Portugal, Spain, Germany, Switzerland and Austria.

Some of the relevant acts date back to the early 1900s or even earlier, for instance the Watercourse Regulation Act in Norway (1917), the Law on fish and fisheries in France (1865) and the Rivers Fishing Act in Spain (1942). However, most of the acts on water resource management, biodiversity protection and renewable energy are more recent and have been formulated under the influence of key EU policies. Certain recent amendments to national legislation have high relevance for the operation or the commissioning of hydropower plants. For example, the Austrian National Water Act revised in 2011 (WRG Novelle 2011) made several mitigation measures such as upstream continuity measures and ecological minimum flow an obligatory requirement. Also in Switzerland, new developments and environmental requirements for hydropower plants are driven by the amendment of the Waters Protection Act in 2011 (Federal Act on the Protection of Waters 2011). The amended Swiss Water Protection Act requires the mitigation of impacts from hydropeaking, the remediation of impairments of the bedload regime and fish migration restoration until 2030 as well as implementation of measures for river revitalisations and improvement of the morphology until 2090 (Schweizer 2017). In Sweden, a number of revisions to the Environmental Code that entered into force in 2019 required the development of a national plan for the revision of hydropower plant licenses with greater focus on environmental goals.

National policy largely defines how environmental requirements for mitigation measures are set for hydropower plants. This mainly takes place in the context of the authorisation procedures for HPP (new authorisation procedures and revision or renewal of authorisations already in place). When planning mitigation measures for new or existing hydropower plants, the mitigation requirements based on legislation, or other types of recommendations (e.g. best-practice guidelines or technical standards) or specific decisions by permitting authorities need to be reviewed and taken into account.

Mitigation requirements for hydropower plants can be distinguished for the following broad domains of environmental improvements at hydropower plants: upstream fish migration, downstream fish migration, flow conditions, hydropeaking, sediment transport, and habitat enhancement.

Requirements for hydropower plants to mitigate the impacts of disrupted upstream fish migration and modified flow conditions are usually based on legislation. In the review of Kampa et al. 2017, relevant requirements in legislative form were found in the majority of the eight countries of the study (Table 1.1). To mention but a few examples: In Austria, ensuring ecological continuity is compulsory except outside of the natural fish zone and very near to natural existing barriers. In Germany, the federal states have set specific technical and hydraulic requirements for upstream fish migration measures. In France, the maintenance of minimum flow is an obligation since 2006 with the requirement to implement minimum flow values by 2014. Concerning minimum flow requirements, overall different methods are used by different countries for its determination (Ramos et al. 2017).

Table 1.1 Overview of the presence of mitigation requirements for hydropower in eight countries reviewed in the FIThydro project (based on the review by Kampa et al. 2017)
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In a number of countries, there is still a lack of requirements based on law to mitigate impacts related to sediment transport, hydropeaking impacts and downstream fish migration, mainly due to knowledge gaps and a lack of proven measures that need clarification through research or pilot studies. For these types of impacts, countries often follow a case-by-case approach when defining mitigation requirements (see overview of situation in eight European countries in Table 1.1). There are exceptions though, for instance, in Germany, several federal states set specific requirements (e.g. on protection screens) for fish protection and downstream migration in ordinances and guidelines (Kampa et al. 2017).

Overall, the EU WFD and recent revisions of national policies are strong drivers for modifying the authorisation procedures for new hydropower plants as well as for revising authorisations of existing plants. The possibility to carry out revisions to permits can help ensure that hydropower plants become environmentally sounder and that state-of-the-art mitigation measures are implemented. However, a large number of hydropower plants in European countries were built prior to modern environmental laws with inadequate environmental requirements in place and no mechanisms to revise them.

In several European countries, a transformation of the regulatory framework is taking place to overcome such barriers. Next to specific technical requirements for impact mitigation, the duration of hydropower plant permits plays a key role in the options available for revisions and inclusion of new mitigation measure requirements. Due to recent changes in environmental legislation and social pressure, permit duration for hydropower plants has in general been reduced in many countries, although the duration of permits still generally differs between new and existing plants.

In Germany, new hydropower plants are usually granted permits up to 30 years, while older plants have ancient rights (often indefinite concessions), which are permits that were granted to operators or installations when the Water Act first came into force in 1960. The permit conditions under ancient rights are often environmentally inadequate from today’s perspective and it is difficult for authorities to compel these operators to modernise. A permit revision is normally only needed if the turbine power is planned to be increased. However, water authorities have recently been getting stricter and asking for mitigation measures. This is also in the case of indefinite concessions, especially when the rivers in question are priority water courses for fish conservation (e.g. Programmgewässer Lachs) (Kampa et al. 2017).

In Sweden, according to a new national plan, all existing hydropower licenses will be reviewed over the next 20 years. Unlimited concessions will no longer be granted, with a maximum for new concessions of 40 years. This will involve placing greater emphasis on mitigation of impacts, including setting minimum environmental flows and the installation of fishpasses (Swedish Agency for Marine and Water Management 2019). Also in Norway, the environmental terms of licensing conditions are reviewed after 50 years (and after 30 years for larger hydropower plants built after 1992). The environmental terms of licenses in Norway that are revised in this context typically include setting minimum flow, requirements for physical habitat improvements, increased continuity, and enhancement of qualities that can be important for the water users (recreation, fishing, etc.). Overall, although the licenses are usually unlimited for publicly owned entities, the environmental terms are revised at regular intervals (Kampa et al. 2017).

In France, although the authorisation procedures have not directly been adapted to the WFD, the definition of mitigation measures is now more ambitious to preserve or restore the good ecological status of streams and rivers. In Spain, an adaptation of existing authorisations depends on the specific permit regime, the water plan of the district and jurisprudence related to determined cases. Overall though changing existing permits is complicated and is bound to produce legal challenges where existing rights of concession holders are affected. Also in Portugal, authorisations for existing hydropower are not yet required to be adapted to WFD requirements (Kampa et al. 2017). Therefore, the level of progress made is diverse across Europe and key steps still need to be taken for an ambitious approach for more environmentally sound hydropower across the continent.

In general, mitigation requirements for new and for existing HPP do not differ substantially, if there is an option to revise existing permits. In case the permit of an operating HPP runs out, in all eight countries reviewed by Kampa et al. (2017), the same conditions as for new authorisations apply in the process of permit renewal. This means that mitigation measures may be required for existing HPP, even where none were required before.

Regulations relevant to HPP authorisation may outline aspects that should be considered in addition to environmental conditions, when setting mitigation requirements. Consideration of cost (dis-)proportionality, cost balancing and limits on the economic feasibility of the HPP are the most commonly additional aspects taken into account in authorisation procedures. Therefore, the implementation of mitigation measures is usually not decided solely upon ecological criteria.

1.3 Conclusion

Policy requirements need to be considered carefully when taking decisions on mitigation measures to reach policy objectives, both in the relicensing process of existing HPPs and the licensing of new HPPs. The overarching framework is set by key EU legislation in particular the Water Framework Directive, EU policies on nature and biodiversity protection and the EU agenda for renewable energy and climate change mitigation and adaptation. The EU policy framework is further specified and operationalised by national legislation that provides the regulatory setting for planning and operating hydropower plants and mitigation measures in each European country. The review of policy in eight European countries in the FIThydro project has shown how recent changes in environmental legislation as well as social pressure have generally reduced permit duration for hydropower plants and how the WFD and other national policy revisions have been modifying authorisation procedures for hydropower at the benefit of implementing mitigation measures. The impacts of hydropower for which mitigation is most commonly required by legislation include the disruption of upstream fish migration and the modification of flow conditions. For other types of impacts, in particular related to sediment transport, hydropeaking and downstream fish migration, relevant legislative requirements for mitigation are largely missing due to uncertainties and the need for more research on the effectiveness of mitigation measures.