Abstract: Beneath crowded streets: concepts for optimal subsurface use in cities
Cities increasingly depend on the subsurface to support essential societal functions such as energy supply, climate adaptation, and various other activities. As global urbanisation accelerates, dense urban areas face growing competition for limited subsurface space. Subsurface planning and permitting procedures require upfront assessments of impacts and their spatial extent. Uncertainty in actual use of subsurface activities result in conservative safety margins and subsequently inefficient allocation of subsurface space (i.e. artificially scarcity of space). These inefficiencies persist because regulatory frameworks mandate fixed spatial reservations and existing governance methods and tools lack the capacity to support dense, multifunctional, use of subsurface resources, which is especially needed in the densest urban settings.
To enable more efficient, multifunctional use of the subsurface, a shift toward adaptive governance is needed. This could be done by monitoring and evaluating actual use and periodically adjusts spatial claims based on actual, dynamic subsurface conditions. Such an approach would allow closer spacing, coexistence, or even integration of different functions, helping local authorities and society to manage complex interactions among for example, ATES and BTES systems, stormwater infiltration, groundwater contamination plumes, and extraction activities.
To establish such a subsurface governance framework, research investigates the need for, and feasibility of, adaptive, multifunctional governance of subsurface space in urban environments with (in time and space disconnected but) overlapping uses. It further evaluates to what extent dense adaptive planning is technically, legally, and financially viable as a framework for coordinated, high-density subsurface utilisation.
