Litigation over water consumption will continue to grow as crises (climate, economic or energy) follow one another. The resulting judgments are particularly instructive, since they are a meeting point between public law, the law of obligations and sometimes property law. As shown by a judgment handed down on 7 October 2026 by the First Civil Chamber of the French Supreme Court (Cour de cassation) concerning billing mechanisms (Civ. 1st, 7 October 2026, No. 24-21.655, FS-B).
In this case, the Société d’Aménagement Urbain et Rural (SAUR), the delegated operator of the public drinking water supply and sanitation service for the Pays de l’Or urban community, had until then billed the owners’ association of a residential building a single fixed subscription of around fifty euros per half-year. From 2019, it decided to bill as many subscriptions as there were dwellings served, so that the amount billed increased tenfold. On receiving an invoice of more than 10,000 euros for one half-year, the owners’ association informed its supplier that it refused to pay without a precise justification of how the fixed charges were calculated. Ultimately, the association decided to sue SAUR for annulment of the invoices, and SAUR counterclaimed for an order that the association pay the sums due under the invoices.
The association prevailed on appeal, the court applying settled case law under which the absence of justification for the fixed portion of the bill prevents the delegated operator from claiming payment of it. The operator then appealed to the French Supreme Court (Cour de cassation), raising the following point of law: must the delegated operator of a public service that sues for payment of invoices whose fixed portion is expressly set out in the legislation justify those fixed charges to the subscriber who disputes liability to pay them? The Cour de cassation partially quashed the appeal judgment in a particularly detailed ruling, owing to the complexity of how the texts interact (to which we will return), holding in substance that, on the one hand, the information required by the ministerial order of 10 July 1996 and by the local drinking water service regulations must appear on the invoice, which suffices for its amount to be regarded as justified and, on the other hand, that the subscriber is bound to pay the sum shown on the invoice unless it proves fault on the part of the delegated operator. It follows that the Court of Appeal could not require the drinking water operator to provide justifications not provided for by the texts in order to reduce its claim, and that the subscriber, having failed to prove any fault on the operator’s part, had no choice but to pay the invoice.
The judgment under discussion is particularly interesting in that it puts an end to well-established case law requiring the operator to justify the fixed portion of the water bill (I), which has significant theoretical and practical consequences (II).
I. The reversal: a price set out in a text is a justified price
In reaching its decision, the French Supreme Court (Cour de cassation) carries out a watchmaker’s work, revealing to the reader an inconsistency between the spirit of the texts and the case-law interpretation derived from them. The solution is admittedly meticulous, but it is so dense that its detail calls for review. As a preliminary point, it should be recalled that the ordinary courts held that they had jurisdiction in this case, since the dispute concerns the drinking water distribution and collective sanitation service, which is an industrial and commercial public service, disputes relating to which fall within the jurisdiction of the ordinary courts where they concern the performance of the subscription contract, which is private in nature, between the user and the service (TC, 24 May 2004, No. C3396, Sté régionale de distribution d’eau). It is therefore quite natural that the dispute ended up before the First Civil Chamber of the Cour de cassation which, before delivering its ruling, sought, with great clarity, to highlight a form of inconsistency between the texts and their interpretation.
On one side, the texts. Since the Water Act of 3 January 1992, and its overhaul by Law No. 2006-1772 of 30 December 2006, the General Local Authorities Code (code général des collectivités territoriales) has regulated the price of water in a two-part structure: one part proportional to the user’s consumption, and a fixed part linked to the costs of the service. Among other provisions, the 1st paragraph of Article L.2224-12-4 of the General Local Authorities Code thus provides that “any water bill shall include an amount calculated according to the volume actually consumed by the subscriber and may, in addition, include an amount calculated independently of that volume according to the fixed costs of the service and the characteristics of the connection, in particular the number of dwellings served.” The ministerial order of 10 July 1996 on bills for water distribution and wastewater collection and treatment, for its part, meticulously describes the separate headings that must appear on the water bill and their content. In other words, the fixed portion of a water bill is modelled on the formal requirements of the ministerial order. In addition, there are the drinking water service regulations adopted by local authorities, in this case the Pays de l’Or, which also tell operators how the fixed portion must be set out in the bill.
On the other side, the case law. In rejecting SAUR’s claim for payment, the Montpellier Court of Appeal followed a long-standing and settled line of case law. In a judgment of 11 January 2000 (Civ. 1st, 11 January 2000, No. 97-16.530) handed down under Article 13 of Law No. 92-3 of 3 January 1992 then in force, the French Supreme Court (Cour de cassation) had held that the subscription charge had to be calculated taking into account the fixed costs, which the lessee operator was required to justify. That solution required the operator, whenever the user disputed the amount billed, to demonstrate its precise nature and amount, failing which the sum would be deemed not due. This was nothing less than the requirement that the lower courts placed on the operator, which had never justified what the fixed portion claimed for each of the 190 dwellings consisted of.
Clearly, the intransigence of the case law clashed with the stated aim of transparency of the laws, orders and regulations. If the texts themselves set out the fixed portion of the bills, can the operator legitimately be criticised for not justifying it? It is in this spirit that the French Supreme Court (Cour de cassation) reversed its position on 7 October 2026. On the combined basis of Article 1217 of the Civil Code, Articles L.2224-12, L.2224-12-3 and L.2224-12-4 of the General Local Authorities Code, the ministerial order of 10 July 1996 on water distribution bills (in the version prior to that resulting from the order of 2 October 2024) and Article 12 of the local drinking water service regulations of the Pays de l’Or, the Court observes that the texts have evolved since 2000. The Law of 30 December 2006, in pursuing an aim of transparency, itself defined the components of the fixed portion of the bill, communicated to users through the distribution of the service regulations. This legislative development, combined with the concern to harmonise the conditions under which the price of the water service is payable with the already established case law under which the subscriber must pay its bills unless it proves an extinguishing event or fault on the part of the operator (Civ. 1st, 30 March 1999, No. 97-13.047; Civ. 1st, 4 February 2015, No. 13-28.379; Civ. 1st, 14 November 2018, No. 17-21.453), led the Court to modify its case law of 11 January 2000. From now on, only the information required by the 1996 order and by the local regulations must appear on the bill, and the operator is not required to provide the subscriber with evidence justifying the amounts of the headings making up the fixed portion. The subscriber therefore remains bound to pay the sum billed, including its fixed portion, unless it proves fault on the part of the operator, which may consist, in particular, in a breach of that order and those regulations. Only such a breach can deprive the operator of the part of the price affected by it.
II. The theoretical and practical contributions of the judgment
Beyond water litigation strictly speaking, the judgment of 7 October 2026 appears to lay the foundations of a principle that will interest contract lawyers. Where a text (statute, order, published service regulations) precisely defines the composition of a price and brings it to the debtor’s attention, that text in itself serves as justification. The debtor can no longer demand from its creditor transparency beyond what the regulations require. Only a breach of the text can justify withholding payment. The judgment thus provides valuable pointers for interpreting the provisions of the Civil Code resulting from the reform of 10 February 2016 that impose on the creditor a duty to give reasons. This is notably the case of Articles 1164 and 1165 of the Civil Code, which allow one of the parties to set the price unilaterally in a framework contract and in a service contract, provided that it “justifies the amount in the event of dispute”. It is easy to imagine that, in particular sectors, the price of services may be meticulously regulated, which could lead to an exemption from the duty to give reasons.
For municipalities and groupings of local authorities, the solution puts the service regulations back at the heart of the evidential framework. This document, drawn up by the municipality or grouping pursuant to Article L.2224-12 of the General Local Authorities Code, defines the composition of the fixed portion and must be given to each subscriber. Local authorities therefore have every interest in ensuring that their service regulations are precise, regularly published and compliant with the cap set by the order of 6 August 2007, which limits the portion not proportional to the volume consumed to 30% of the cost of the service for a reference consumption of 120 cubic metres per year (40% for rural municipalities, tourist municipalities being excluded from the cap). Regulations that are imprecise, poorly disseminated or exceed this cap are likely to undermine the recovery of charges.
For operators and providers of industrial and commercial public drinking water and sanitation services, the judgment significantly lightens the litigation burden on delegated operators, who no longer have to produce detailed cost accounts for each subscriber disputing their bill. Formal rigour, on the other hand, is heightened: any breach of the order of 10 July 1996 or of the service regulations will deprive the operator of the part of the price affected by that breach.
For subscribers, all is not lost, since the ministerial order, like the service regulations, remains an administrative act that can be challenged before the administrative courts (CE, 16 February 1996, No. 141485, Synd. Copro. Résidence “La Balme”), which may, where appropriate, deprive the billing of its legal basis.
Finally, the reasoning adopted by the French Supreme Court (Cour de cassation) could apply, by analogy, to other sectors in which the pricing of a network service is governed by precise public regulations. This type of litigation may well, in future, attract the attention of economic players whose activities involve considerable water consumption, such as data centre operators, whose cooling needs weigh increasingly on local networks and call for particular vigilance as to the pricing terms applied to them. These operators, often bound to local authorities by specific agreements or service regulations owing to the scale of their abstraction, will have every interest in anticipating this new evidential framework by examining, from now on, the precision of the texts governing their own billing.
