The Deep City project at the École polytechnique fédérale de Lausanne has, for the past several years, been developing a method to identify and qualify the urban areas where underground development is high, particularly for human activities. The fourth dissertation to contribute to this project, begun by the author in 2012, seeks to combine morphological and topological properties of the surface with the hydrogeological characteristics of the underground in order to develop strategies to integrate future underground spaces with the existing urban fabric. This communication will first explain recent progress made on the Deep City method, which promotes an urban planning process that takes underground resources into account prior to the project development stage. Preliminary results from an ongoing case study of the city of San Antonio in Texas will serve to illustrate how the method can be applied from a regional to local scale. The paper concludes by discussing the legal and procedural implications that a controlled three dimensional management of the urban form suggests and the next steps to improve the method.