According to Article 5 paragraph 1 of the Electricity Supply Act (StromVG, SR 734.7), the cantons shall designate the network areas on their territory.
Since Network Level 1 (the transmission network) is operated solely by the national grid operator (Swissgrid), the cantons only have to allocate network areas at Voltage Levels 3, 5 and 7. The network areas are allocated to cover the entire cantonal territory, usually by a decree by the executive or the parliaments in the cantons.
The following figure shows an example of how the network area allocation can be carried out via Network Levels 3, 5 and 7.
