Question juridique clé
Whether the municipality could revoke a final water connection fee decision and increase the fee retroactively.
Solution extraite
The original fee decision was protected by legitimate expectations and could not be revoked; the later reassessment was unlawful.
Motifs extraits
Gebührenverfügungen are generally irrevocable once final and paid. The initial error was not obvious to the addressees, so trust protection prevails over correct application of law.