BDLISA, the French national hydrogeological database, is a tool for locating reference data on groundwater across France. BDLISA (Base de Données des LImites des Systèmes Aquifères) was set up to provide maps of hydrogeological units for users in mainland and overseas France (except Mayotte).
31 May 2018
Homepage of the BDLISA website Homepage of the BDLISA website

Homepage of the BDLISA website.


Construction of Version 2 of the BDLISA hydrogeological reference base, covering all of mainland and overseas France, was completed in 2018.

After the release of Version 1 in August 2015, consolidation work based on user feedback continued through 2016 and 2017. Version 2 includes  over 600 modifications (attributes and/or geometry) to the dataset used for the previous version.

More specific improvements have also been made and several new features are now included in the new data set, such as:

  • overhaul of the thematic layer for karstic zones, in particular to extend the mapped entities beyond outcrops alone to better characterise their content;
  • a new thematic layer on loose alterites in the bedrock domain, drawing on a compilation of existing maps and the results of alterite modelling, in collaboration with the BRGM's Regolith team;
  • slight simplification of the contours  of all hydrogeological entities in order to streamline the database while maintaining its compatibility with uses at the 1:50 000 scale;
  • maps of the hydrogeological entities of Mayotte.

Work on BDLISA began in 2006, after a conceptualisation and testing phase.  The studies were conducted region by region by the regional agencies of the Ministry of Ecology, the water and environment offices and the BRGM's regional divisions. Local and regional authorities, research organisations and engineering consultancies were also involved. The BRGM was commissioned to build up the reference base and to consolidate its contents at the national scale, as required by the national plan for data on water (SNDE).

With the completion of database construction, work is now focusing on 2-3 year iterative cycles, after which any anomalies observed by users will be corrected and proposed improvements incorporated to reflect scientific and technical advances in knowledge on the subsoil.

Map of outcropping hydrogeological entities, classified by type, in Version 2 of BDLISA, the French hydrogeological database Map of outcropping hydrogeological entities, classified by type, in Version 2 of BDLISA, the French hydrogeological database

Map of outcropping hydrogeological entities, classified by type, in Version 2 of BDLISA, the French hydrogeological database.


What is BDLISA for?

BDLISA (Base de Données des LImites des Systèmes Aquifères) was set up to provide maps for users in mainland and overseas France of the aquiferous geological formations known as "hydrogeological units" and defined in accordance with common rules. A single system of identification is applied for all formations, which are described in terms of their hydrogeological characteristics.  The information is entered into a database linked to a shared set of reference maps that are freely available for consultation by the public. Any user of BDLISA can easily display, process and exchange the information attributed to one or more hydrogeological units.

BDLISA is a reference geographical database that divides France into hydrogeological units (geological formations with or without aquifers).  A hydrogeological unit is part of a geological area which is:

  • defined at a particular geographical scale, referred to as the "level",
  • linked to a type of geological formation, referred to as the "theme",
  • defined by its aquiferous potential, referred to as its "nature",
  • characterised by a type of porosity (which identifies the main patterns of water circulation), referred to as the "environment",
  • characterised by the presence or absence of a free and/or captive water table, referred to as its "status".

BDLISA is a reference database that:

  • contributes to the development and improvement of the reference datasets being built up to form the Water Information System (SIE) on groundwater:
  • the reference database on groundwater masses, established in line with Directive 2000/60/EC of the European Parliament and Council of 23 October 2000,
  • the reference database on groundwater monitoring sites,
  • provides coherently designed maps of groundwater resources within French territory,
  • incorporates information associated with each hydrogeological unit (level, theme, nature, environment and status),
  • facilitates exchanges of the data between different users.

BDLISA also contributes to the production of knowledge required to guide and implement national and EU policies on groundwater.

How can I access BDLISA?

A new dedicated website for access to BDLISA is now available on line, which has been designed to centralise and improve access to all BDLISA information and explanations. The site is available at:

As a consequence of the creation of this new website, the distribution procedure for BDLISA has changed. All data considered essential to the construction of BDLISA are in the "BDLISA reference base" (as defined for the water information system) and downloadable from the SANDRE website. An "operational" version has also been produced, containing supplementary data but also the "Reference base" data, rewritten to offer a series of relevant data products for users. This is available at :

BDLISA is available in the SHP (QGis, ArcGIS®), geodatabase (ArcGIS®), SQLite and Geopackage (OGC®) formats. Instructions for use are downloadable with the database: BDLISA may be reused under the open licence conditions applying to public information.

BDLISA is also available through cartographic web services that allow displays of the hydrogeological units via a GIS or web application.  Details on these services may be consulted on the Eaufrance portal  (under the heading "Les services de valorisation").


The project was funded by the Ministry for the Ecological and Inclusive Transition, the French Biodiversity Agency (AFB), the Water Agencies and the BRGM. The work was undertaken in accordance with a national methodology developed by SANDRE (the national administration agency for water data and databases), which is also responsible for distributing the database.