Facts
A. is the owner of the Hammer property in the municipality of Cham and the holder of a long-standing water use right in the eponymous hydropower plant on the Lower Lorze. On October 5, 2015, A. submitted two building permit applications for the renovation of the Hammer hydropower plant: The first concerns the residual water rehabilitation and the restoration of fish passability, the second the replacement of the power plant turbine and generator as well as the repair and automation of the weir system. The municipality of Cham forwarded all three building permit applications to the Building Directorate of the Canton of Zug for the purpose of coordinating the procedures.
The Cantonal Council of Zug dismissed an objection from WWF Switzerland and WWF Zug regarding the renovation of the Hammer hydropower plant, insofar as it entered into the matter. It set the non-compensatory residual water quantity of the Hammer power plant at 400 l/s. Of this, 200 l/s are to be released as operating water for the downstream migration of fish and the remaining 200 l/s over the residual water section. At the same time, the Cantonal Council granted various construction, exemption and special permits.
WWF Switzerland appealed against the decisions of the Cantonal Council to the Administrative Court of the Canton of Zug, which, however, dismissed the appeal. Thereupon, WWF Switzerland filed a public law appeal to the Federal Supreme Court.
Considerations
The Federal Supreme Court upholds the appeal. It states that the long-standing water use right of the respondent, recognized by the Canton in 1967, constitutes a special use right to a public body of water, but this cannot apply indefinitely, but only until the amortization of the investments made, at most for 80 years. The right must therefore be subject to the current…