The reactivation of the Hermann Hesse Railway between Calw and Renningen in Baden-Württemberg demonstrates how significantly bats can impact the budget of a public project. Originally budgeted at €49 million, the railway line has now ballooned to €207 million. Nearly 40 percent of the total expenditure, or approximately €80 million, is earmarked for species protection. This cost explosion highlights the clash between nature conservation and construction practices in Germany. (stuttgarter-nachrichten: 10.11.25)
Bats determine the tunnel project
Around a thousand bats, including the whiskered bat, live in two historic tunnels near Hirsau and Forst. An extraordinary tunnel project is being built for these nocturnal creatures, in which a concrete wall separates their habitat from train traffic. This technically demanding construction project is considered unique nationwide, but it is incurring high costs.
In addition to the new tunnel construction, replacement roosts, biotopes, nesting boxes, and bat towers are being built. These extensive measures are further driving up costs. Every single measure must comply with EU regulations, which makes nature conservation expensive and complex.
Millions for nature conservation instead of mobility
According to the Federation of Taxpayers, the Hermann Hesse Railway is now one of the most expensive infrastructure projects in the country. The protection of the bats alone costs more than the originally estimated total budget. Critics argue that the financial expenditure is no longer proportionate to the benefits.
Proponents, however, emphasize that the railway will save CO₂ in the long term and connect the region to the rail network. Nevertheless, the massive cost explosion is causing debate. Many are questioning whether a single group of animals—however worthy of protection—justifies such high sums.
A Construction Project with Symbolic Power
Despite criticism, the construction project is progressing. The railway line is scheduled to begin operation in early 2026. Those responsible see it as a symbol of environmentally sound progress. However, while the focus is on nature conservation and bats, economic viability and efficiency are increasingly being sidelined.
The Hermann Hesse Railway exemplifies how ambitious environmental regulations can propel projects into new dimensions. When the protection of tiny, nocturnal birds accounts for almost half of the project costs, the question of proportion and common sense inevitably arises.