25.06.2025
Elo Rasmann, environmental expert
The role of environmental monitoring in Rail Baltica
No map is the same as the landscape. The environmental monitoring accompanying the construction of Rail Baltica reminds us of this old truth every day: even the most thorough environmental impact assessments – based on science, expert opinions and decades of experience – still remain predictions. Reality on the ground can confirm or refute them. That is why continuous and systematic environmental monitoring is an integral part of the construction of Rail Baltica. It allows us to assess the impact that the railway actually has on nature, people and the living environment – both during construction and after the trains are already moving. When building large projects, it is not possible to leave nature completely untouched, but it is possible and necessary to reduce the impact and make sure that the implemented mitigation measures actually work. In certain cases, the size of the real impact or, conversely, the effectiveness of the implemented mitigation measures can be verified later with monitoring activities. This is also what we are doing in the RBE project.
Mitigation measure: measures to prevent, avoid, reduce and mitigate the adverse environmental impact of the planned activity and, where justified, to remediate it. Environmental measures also include environmental monitoring. (Environmental Impact Assessment and Environmental Management System Act).
What is an environmental monitoring plan?
The Rail Baltic Estonia Environmental Monitoring Plan is a nearly 60-page document that describes our monitoring framework. The monitoring plan sets the goal – what kind of monitoring needs to be organized, what information we want to collect from the monitoring, how long the monitoring needs to be carried out, and what will be done with the collected results and conclusions. It is a constantly updated document, as the results of the monitoring are the basis for improving the future monitoring cycle and supplementing the mitigation measures during construction and later operation.
Our environmental monitoring plan covers several areas – fauna, flora, aquatic environment, noise and vibration. Environmental monitoring is carried out by the construction contractor, commissioned experts in the field and employees of the Environment Agency.
Monitoring plan focus and methods
Wildlife monitoring is the most diverse of them, focusing on monitoring protected species most affected by construction and expanding to study the impact of the barrier effect after the railway is completed.
Barrier effect: The barrier effect is brought about by a physical obstacle that prevents the free movement of species populations. For example, transport infrastructure causes a barrier effect by preventing road avoidance (due to noise or vibration disturbance), death in traffic and acting as a physical barrier, because it reduces the free movement of species and the successful crossing of infrastructure. The ability of individuals to disperse and migrate is key to the long-term survival of species. Movement barriers prevent individuals from searching for food and shelter and finding a breeding partner, and also reduce the survival of young animals. To avoid the transport barrier effect, the infrastructure must be made passable to wildlife by means of passages. The impact of the barrier effect varies from species to species. (Animals and Traffic in Estonia, 2010) .
During construction, the impact of habitat change and/or disturbance from construction activities on individual individuals (e.g. lesser spotted eagles, black storks) or local populations of individual species (amphibian habitats, wild game, etc.) will be monitored.
After the railway is completed, it is important to check whether the railway, which is almost completely surrounded by fences and thus acts as a barrier, is passable for animals. In other words, whether the animal crossings built as a mitigation measure provide sufficient opportunities for animals to cross the railway, whether animals find ecoducts and dare to use animal tunnels, and whether individuals that accidentally get caught between the railway fences find places to jump back to a safe environment.
The Rail Baltica project will create new habitats for amphibians and rock lizards and restore them to wildlife. Monitoring will verify that the habitats specifically created to compensate for habitats destroyed during the construction of the railway are being used and remain of high quality and suitable.
Aquatic environment seira is largely the responsibility of the contractor, as they have the most up-to-date information on the schedule of works, the nature of the work to be carried out and the methods to be used. Monitoring checks that construction activities do not cause pollution to surface water bodies (including excessive suspended solids) or boreholes. In certain cases, the water level in boreholes is also monitored.
On the other hand water and vegetation monitoring of bogs is our responsibility, as the railway will be built through several wetlands. This means that water levels in the bogs will be monitored continuously, and an assessment of vegetation coverage and species diversity will be prepared on two or three occasions. The construction of the railway will have a long-term impact on the wetlands, which is why monitoring must also be carried out after the railway is completed.
Monitoring plays an important role in decision-making
Why monitor at all? The environmental monitoring plan monitors protected species, mainly species in protection categories I and II. They can also be considered so-called umbrella species, i.e. species whose good fortune can be assured that many other, often more common, species will also do well.
Roof types: According to the concept of the umbrella species, by protecting a certain species, other species living in the area will also be protected. Unlike a support species, the removal of which changes the entire community, the protected communities would continue to exist and function even without the umbrella species (Zacharias, Roff, 2001). Due to the correlative relationship, the characteristic feature of the umbrella species is sensitivity to human impacts that threaten many other species (Fleishman et al., 2000). (A. Lõhmus, M. Soon, 2004)
Species with a higher conservation category often have very specific habitat requirements and/or need a large area of land to thrive. Often an area that is not overly fragmented by cultivated landscapes or roads, or areas with a sufficiently high proportion of old-growth forest.
It should be understood that monitoring itself does not improve the living conditions of the species being monitored or change the water quality. The results of monitoring provide insight into the situation and the opportunity to seek solutions that could then improve it.
Water monitoring provides an opportunity to react quickly, assess the compliance and quality of construction activities, and make changes to activities if necessary. True, this does not prevent problems, but it does allow us to identify the problem early and mitigate or even avoid it in the future.
For example, if monitoring identifies that the mating or nesting of a protected bird is disturbed due to noise caused by construction, then similar disturbance can be avoided at the latest during the following year's nesting season. Or if monitoring reveals that in some area an unusually large number of bats are entering the railway corridor and are killed in collisions with trains, then this is a clear sign that solutions must be implemented in that area to keep bats away from the railway or direct them to fly over the railway.
A construction project of the size of Rail Baltica has a significant impact on the environment. Therefore, it is our task to do everything we can to minimize this negative impact. One way to assess the effectiveness of mitigation measures, which have been put in place as a result of long and thorough planning, is to conduct monitoring. Thus, through monitoring, we can measure the impact of our activities on the natural environment and make sure that the measures we implement are working.
How did this story make you feel?
2
