The local collective sanitation network plan locates the public pipelines that collect wastewater from a municipality. This technical document, essential before a connection or a real estate sale, is not always easy to obtain: procedures vary from one community to another, and there is no national database that centralizes these layouts.
GIS Platforms and Open Data: Accessing the Sanitation Plan Without Going Through the Town Hall
The traditional approach is to contact the technical service of the town hall or the water syndicate. This method works, but it often requires an appointment, a letter, or a visit to the counter. In recent years, a more direct channel has opened up.
Read also : How to Make the Most of Your Digital Reading: Tips and Resources
More and more intercommunalities are publishing their network plans (drinking water, sanitation, stormwater) on an online user portal, usually accessible from the water billing area. In Brittany and the Grand Est region, several water syndicates have been communicating since 2023 about this cartographic availability to subscribers.
The European INSPIRE directive, transposed into French law, encourages communities to publish part of their geographic data as open data. Regional platforms like GéoBretagne or GéoGrandEst distribute “collective sanitation” or “sanitation zoning” GIS layers that can be freely consulted. Therefore, retrieving the sanitation plan of your municipality can be done from a browser, without a paper form.
You may also like : Ideas and tips to transform your interior with the home section of Communiqués du Net
Not all municipalities have digitized their networks. Small rural communities sometimes only keep paper plans archived in the public works department. In this case, visiting the town hall remains the only option.
Collective Sanitation Zoning: The Document to Request First
Before looking for the precise layout of the pipelines, another document deserves your attention: the sanitation zoning. This plan, annexed to the local urban planning plan (PLU), delineates the areas covered by collective sanitation and those that depend on non-collective sanitation (septic tank).
The zoning answers the first question that any owner or buyer asks: is the land served by the sewer system? If the plot is located in a collective sanitation area, connection is mandatory. The zoning can be consulted at the town hall, but also on the urban planning geoportal for municipalities that have submitted their PLU there.
Difference Between Zoning and Network Plan
The zoning indicates whether an area is covered by the collective network. The network plan, on the other hand, shows the physical layout of the pipelines, their diameter, their depth, and the inspection chambers. For a connection project or earthworks, the network plan is the technical document to obtain, not just the zoning.
DT-DICT Declaration on the Networks and Pipelines Online Service
Individuals planning work near buried pipelines must consult the “networks and pipelines” online service of the single window. This portal lists the network operators present in a given area and allows for the initiation of a project work declaration (DT) or a declaration of intent to commence work (DICT).
The response from the operators includes the plans of their networks in the concerned area, including sanitation networks. This channel is often unknown to individuals, even though it provides access to precise and up-to-date layouts.
- Create an account on the online service of the single window for networks and pipelines
- Declare the area of the planned work (even for a simple connection)
- Receive the plans of the existing underground networks, including sanitation, within a few weeks
This procedure is mandatory before any excavation work. It provides free technical plans that the town hall does not always communicate.
Sanitation Diagnosis and Real Estate Sale: When the Plan Becomes Mandatory
When selling a property, the sanitation diagnosis is part of the technical diagnostics file (DDT). For homes connected to the collective network, the inspection is carried out by the public collective sanitation service (SPANC or equivalent service). The report mentions the compliance of the connection and may include an excerpt from the network plan.
For properties with non-collective sanitation, the diagnosis focuses on the condition of the septic tank and the treatment system. The public network plan is not directly required, unless a future connection is planned in the zoning.
What the Diagnosis Does Not Replace
The sanitation diagnosis verifies the compliance of an existing connection. It does not provide the complete plan of the municipal network. If the project requires knowledge of the layout of the pipelines beyond the plot (to assess the connection distance or anticipate development work), the network plan must be requested separately from the manager or via the online service.
- For a sale: the sanitation diagnosis is sufficient for the DDT file
- For a connection: request the network plan from the sanitation manager or via the DT
- For earthworks: the DT-DICT declaration is mandatory and provides the layouts
The gradual digitization of networks by communities simplifies these procedures, but the pace of online availability remains uneven across territories. In municipalities where the plan is not yet accessible online, the municipal technical service or the sanitation delegate remains the contact to approach, preferably in writing to keep a record of the request.