Damages for concrete damage in the sewerage system directly from the usage relationship: The OVG Schleswig-Holstein has reinforced the position of municipalities.

Municipalities may assert damage to the sewerage system caused by construction work directly from the public-law usage relationship.The Higher Regional Court (OVG) Schleswig-Holstein has, by order dated 23. September 2025 (Az. 6 LA 138/24) confirmed an important principle on liability for damage to public sewerage. The case concerned the question of whether a property owner is liable for damage caused by the discharge of concrete into the public wastewater sewer during a construction project. The decision clarifies how far-reaching the obligations arising from a public-law sewerage usage relationship are and that municipalities can assert their claims for damages directly on this basis.public-law sewerage usage relationship are and that municipalities can assert their claims for damages directly on this basis.

The legal framework: Public-law usage relationship rather than contract

The relationship between municipality and property owner in the use of public wastewater disposal is legally specially structured. Unlike in civil law, it does not arise through contract formation pursuant to §§ 145 ff. BGB, but through the municipal by-law. With the provision of a public wastewater installation, the municipality enters into a public-law usage relationship with the property owners who are connected or have a connection right. Although this usage relationship is unilaterally determined by the by-law, it is referred to in case law as contract-like. Thus, the principles of positive breach of obligation pursuant to § 280 para. 1 BGB by analogy can be applied to breaches of duty. This means: whoever violates their obligations arising from the wastewater by-law and thereby causes damage must pay damages to the municipality.

What it was about: Concrete blocks the wastewater sewer

In the decided case, the defendant was the owner of a property in Neumünster that was connected to the municipal sewerage. After an old building on the property had burned down, he had a new residential house with garage built there. The construction work was carried out by a construction company. In September 2015, the city discovered that the main wastewater sewer in front of the defendant's property was almost completely filled with hardened concrete. The cross-section of the pipe was reduced by 90 per cent, making use practically impossible. The municipality commissioned a specialist company to rectify the damage and billed the property owner for repair costs amounting to €8,960.26. The latter refused to pay, whereupon the municipality filed a lawsuit with the administrative court – successfully.

The court's legal deliberations

The administrative court ordered the defendant to pay. The OVG Schleswig-Holstein confirmed this decision by dismissing the application for permission to appeal. Thus the judgment is final. The court stated that the usage relationship already arose with the connection right pursuant to the wastewater by-law. It was irrelevant whether wastewater had already actually been discharged from the property. What was decisive was that the by-law of the municipality determined when a property owner was to be regarded as a user of the wastewater installation. The defendant's argument that a usage relationship only arose with actual use or on the basis of contractual consensus was rejected by the court. Particularly in the field of public wastewater disposal, it was not necessary for the parties to bind themselves through declarations of will as in private law. Rather, the municipality as the operator of the facility determined authoritatively by by-law who was a user and what obligations were associated with this. A central argument was also that the obligation to not discharge harmful substances such as oil, chemicals or concrete into the sewerage system followed directly from the by-law. The defendant had to account for this breach of duty, as it was related to construction work on his property. The damages claim in the amount of the repair costs was therefore justified.

Significance of the decision and recommendation for practice

The decision of the OVG Schleswig-Holstein strengthens the legal position of municipalities considerably. They can assert costs for damage to the sewerage directly on the basis of the public-law usage relationship without having to rely on complicated contractual constructions. For municipalities, this means legal certainty: as soon as a property is connected or a connection right exists, damages claims can be enforced in the event of a breach of duty. For property owners and builders the decision is a clear warning signal. The formal connection to the sewerage alone entails extensive obligations. If substances such as concrete, oil or other harmful materials are introduced into the public sewerage during construction work, this threatens considerable financial consequences. It is not sufficient to rely on the site management or executing contractors; ultimately the owner remains responsible.

Conclusion and recommendation

Municipalities should structure their wastewater by-laws clearly and emphasise the obligations clearly in order to avoid later disputes. Property owners and building contractors, in turn, must closely monitor construction projects and implement technical precautions to prevent foreign materials from entering the sewerage. An omission can – as in the present case – quickly lead to damages claims. Please contact the experts in administrative law at AVANTCORE Rechtsanwälte in Stuttgart early, so that we can help you to avoid such disputes.