"Benefit" and "protect" reduced to a common denominator

It's in the nature of things: where electricity is produced, interests clash, especially between hydropower and ecology. Nadia Semadeni, objective, competent and goal-orientated, provides a balance. She is Head of the Environment Department at Axpo.

The floodplain landscape in the Aare valley stretches over 315 hectares from Wildegg to Brugg. The area is home to one of the most species-rich ecosystems in the Aargau. At the same time, Axpo operates one of the most powerful hydropower plants along the Aare here: the Wildegg-Brugg power plant (KWWB). Like any power generation plant, the facility, which was completed in 1953, has an impact on nature and the environment. Conflicts are inevitable.

The task of Nadia Semadeni, Head of the Environment Department at Axpo Hydro & Biomass, is to strike a balance here. The aim is to maintain and optimise electricity production capacities while protecting nature and biodiversity. Born in Graubünden, she studied environmental engineering at ETH Zurich. For almost 20 years, she has been successfully reconciling the "utilise" and "protect" counters for Axpo and bringing together the various stakeholders. Passionately, objectively and with great expertise.

Wherever and whenever Axpo plans the construction of a power plant or the conversion or expansion of a plant, the legal requirements and project-specific conditions imposed by the authorities must of course be complied with. Relevant for the Environment department: the environmental impact assessment (EIA). It is part of the authorisation procedure. Negative effects on the environment must be prevented, minimised or compensated for with compensatory and replacement measures. The environmental impact report (EIR) serves as the basis for the assessment. It sets out the legal framework for major projects and must therefore provide the required proof of environmental compatibility. The EIR is the basis for assessment by the decision-making authority. 

Expert opinions are recognised in turn

Nadia and her team - all with a technical or scientific background, including fish biologists - prepare a considerable proportion of the reports and expertises in-house, carry out field studies or commission and coordinate them. The expertise pooled here is crucial to the success of the projects. Two decades ago, Axpo, then still NOK, decided to build up its own expertise in the field of environmental protection. The topic was too important. "We didn't want to be reliant on external expert opinions, we wanted to have authorisations and official matters in our own hands," says Nadia.

In view of the expert reports prepared by Axpo, some critics might have thrown up their hands and shouted: "Purely a courtesy report! They were proved wrong. Axpo's reports have long enjoyed the necessary credibility among both the authorities and environmental protection representatives. Nadia and her team are solely committed to the matter at hand and deliver qualitatively flawless, reliable data that serves as a basis for all parties involved. The currency is quality and transparency. "We are not salespeople, neither internally nor externally, we don't sugarcoat, but we don't dramatise either," Nadia makes clear and immediately points to one of the most recent examples: "We clearly stated that the flushing of the Pigniu reservoir affects the fish of the entire Vorderrhein and justified our assessment. However, the emptying was necessary despite the risk to the fish because we had to guarantee the long-term electricity production of the plant and the safety of the dam. We are currently analysing the extent to which the animals have been negatively affected and evaluating the data.

Copy-paste does not exist

To ensure that a project is successful, Nadia and her team involve the authorities as well as representatives of the municipalities, local residents and NGOs at an early stage. In Switzerland, more than 30 organisations such as Aqua Viva, the WWF, Pro Natura and the Swiss Fisheries Association have submitted complaints. It takes a great deal of diplomatic tact and drive to reconcile the different concerns of all parties.

Nadia is constantly on the move, advising the internal project managers and construction colleagues, reconnoitring the initial situation on site at the power plants with the authorities and NGO representatives, evaluating and forecasting, informing, explaining and discussing, balancing out concerns and sometimes setting limits. The fact that she is always "sandwiched" (in Nadia's words) between electricity supply and ecology is not a problem. "The aim is to create a win-win solution. If we don't also offer the other parties a benefit, we lose time or risk the project failing".

Copy-paste does not exist in this job. Every power plant is different, just as the starting point for a project is different, as are the goals and the path to get there. "In all these years, I've never experienced a situation twice," says Nadia. The pumped storage power plant Limmern (PSWL) high up in the Glarus Alps is not comparable with the urban power plant Rüchlig on the Aare. The construction of the PSWL was also a mammoth project, even for Nadia, who was on board for more than 15 years. The Rüchlig plant, on the other hand, was completely renovated in around three years as part of the new licence, equipped with fish-friendly Kaplan turbines and two ascent and one descent aid built at the doping power plantfor the fish .

"Every single fish is a huge joy"

The example of Hydro Beznau shows how successful species protection measures can be. Here, Axpo built a state-of-the-art fish ladder as part of the 2011 tightening of the Water Protection Act (see box). The ladder is around 175 metres long and consists of 45 basins that are connected by a vertical slot width of 40 cm. This means that the staircase offers as many of the 32 fish species found in the Aare as possible the opportunity to ascend. Because fish swim against the current, orientating themselves towards the main current, an extensive attracting current must be provided to make it easier for them to find the entrance. To minimise the loss of water for the attracting current, new types of attracting current pumps were installed. This makes it easier for the animals to find the entrances to the stairs and minimises losses in current production. As checks have shown, around 77,000 fish passed upstream through the facility over a period of 293 days. 29 species were counted. A great success. "Every single fish that can now swim upstream is a huge joy and confirmation: Every examination, every session was worth it," says Nadia.

But back to the KWWB. There's still a lot to do here. According to the Water Protection Act, the plant must be rehabilitated. While the ascent for fish has been well solved for some time with stairs or fish lifts, for example, the descent of fish at hydropower plants with an expansion water volume greater than 100 m³/s remains a sticking point. Fish also follow the main current downstream and thus swim into the turbines, which are dangerous for them. With such large turbines, the losses can be considerable, especially for large fish. Research is still lacking a practicable solution here.

Using the KWWB as an example, Axpo has presented a comprehensive pilot study that will serve as a template for fish migration at large power plants in the future. According to the study conducted under the auspices of the Aare-Rhine Works Association, the fish can be successfully channelled past the turbines via a guide rake bypass system with a so-called bar rack. However, the costs for this are high. Alternatives are described in preliminary reports. The solutions are therefore available.  Now it is up to the authorities to decide on an option, emphasises Nadia. "Only then can we actually make a difference for the fish and make the all-important contribution to biodiversity. Discussing and producing paper alone is not enough".