Tunnels are common elements of transport infrastructure projects in most EU member states and the benefits are many: they ensure the passage of physical obstacles such as mountains, they reduce travel distances and travel time, they can alleviate surface congestion, they can contribute to climate change mitigation and -adaptation and they can improve traffic flow, leading to faster and more reliable transportation.

Further, tunnels are expensive and complex structures established in (very often) environmentally and geologically complex and vulnerable locations.

Consequently, while tunnels can reduce some types of environmental impacts, they also have the potential to create other types of environmental impact.

Around 80 participants connected, from both inside and outside of EU, on 5th October 2022 to the webinar on  "Sustainable Underground Infrastructures Development. Methods, tools and applications".


Target audience

The main target audience was composed of authorities and project promoters involved in underground tunnelling projects, with a water and transport focus.



Early identification of potential environmental impacts and corresponding mitigation in tunnel projects, can contribute to reduce the risks of environmental damage as well as save time and resources. Consequently, this promotes economic and environmental feasibility as well as public consent.

Tunnels, by nature, impact on water bodies and, as a large proportion of NATURA 2000 sites include water dependent elements, an early attention to water bodies also facilitates attention to possible hydraulic links between projects impact zone and NATURA 2000 sites.

The Hydrogeological Excavation Code (HEC) is a series of investigative tools aimed at promoting timely and environmentally sustainable tunnel project development.

The application of the HEC can provide preventive measures in order to avoid issues such as project delay, cost increase, negative public opinion, economic and environmental irreversible damages etc.

The webinar aimed to raise the awareness of stakeholders on topics such as:

  • General aspects related to developing tunnel projects
  • The EU environmental directives and their significance in the planning, design and construction of tunnels (including the application of JASPERS’ checklist tool on the Water Framework Directive).
  • Ex-ante project risk analysis with focus on hydrogeological risk, and importance of project specific and geotechnical data.
  • The Hydrogeological Excavation Code (HEC) and the use of HEC in tunnel design, in environmental impact assessment and in the identification of mitigation measures.
  • Case studies including pre-submitted contributions from participants.

Participants had the chance to join Q&A sessions.


For any further enquiry on this webinar and in general on the activities of the JASPERS Knowledge Platform please write an email to jaspersnetwork@eib.org