Question juridique clé
Whether the municipality could demand additional connection fees after the original fee decisions had become final.
Solution extraite
The later recovery was not permissible; the fee decisions were treated as essentially non-revisable under the applicable cantonal law and trust protection.
Motifs extraits
No change of circumstances occurred. The error resulted from wrong legal application, not from an incomplete factual basis. Given the strong reliance interest and the similarity to finalized tax assessments, the cantonal court’s refusal to allow a retroactive correction was not arbitrary.