The Bedřichov water supply tunnel in the Jizerské Hory Mountains is one of only a limited number of underground drifts in the Czech Republic, which intersects a granite body - the Krkonoše- Jizera Composite Mssif. The tunnel´s importance in this respect is especially due to its unusual lenght (6km) and the technical attributes of the method of contruction (a combination of the tunnel boring method - TBM - and the drill and blast technology used in tunnel driving).