Federal Act
on the Protection of Waters
(Waters Protection Act, WPA)

¹Any­one with­draw­ing wa­ter from any body of wa­ter shall be re­quired to prove to the au­thor­it­ies by means of meas­ure­ments that he will main­tain the re­quired wa­ter en­dow­ment. If the cost of such a pro­ced­ure is un­reas­on­able, evid­ence may be provided by a cal­cu­la­tion based on the wa­ter bal­ance.

²If he proves that the ef­fect­ive rate of flow is tem­por­ar­ily lower than the re­quired wa­ter en­dow­ment, he is only ob­liged to main­tain a re­quired wa­ter en­dow­ment equal of the ef­fect­ive rate of flow dur­ing the peri­od in which such a situ­ation ex­ists.