Published on 4 July 2025

The Lake Constance Conference of Surveying Authorities

For the largest part of Lake Constance, there are no legally defined borders. Within the framework of the Lake Constance Conference, the surveying authorities of the neighbouring countries resolve technical issues relating to Lake Constance in a pragmatic and cooperative manner.

Lake Constance is the heart of a border-crossing natural and economic region in the middle of Europe. Spatial data is needed to resolve or process many border-crossing issues, topics and tasks from business, administration and science that come together there. In addition, with Switzerland as a partner country, there is also the issue of an External border of the European Union.

The production and distribution of spatial reference data, landscape models, national maps, aerial photographs, elevation and gravity models and the real estate cadastre is a national legal mandate for which the surveying authorities of the four countries around Lake Constance (Baden-Württemberg, Bavaria, Austria and Switzerland) are responsible.

An annual meeting of the surveying authorities is held with purpose of exchanging informations and discussing these issues in the spirit of partnership.

The technical processing of the above-mentioned cross-border issues was handled until 2024 by a permanent working group on the Lake Constance geodata pool. This working group made analyses, worked on pilot projects and proposed solutions to improve international cooperation and the border-crossing use of geodata:

  • the coordination of processes,
  • the harmonisation of geodata and
  • the launch of new applications.

Further information and results of the work

Technical boundary in the Lake Constance

Partners in the Lake Constance Conference

Federal Office of Topography swisstopo

Department Communication and Web
Seftigenstrasse 264
3084 Wabern