3D groundwater modelling for the concession of a drinking water well

Ramona Nüssli, 13. August 2019

Validation of the pumping rate and depth of withdrawal of a planned drinking water well in Rodund, AT, using 3D groundwater modelling.

Catchment area of the well for a pumping rate of 5 l/s (left) and 15 l/s (right)

Groundwater is by far the most important source of drinking water in Austria. The duration of a concession is usually limited in time. In the region Vorarlberg in Austria the installation of a new drinking water well is planned, after the expiration of the concession for the existing drinking water supply. To get a new concession, it is mandatory to prove that the required water quantity and quality could be ensured within the local hydrogeological conditions.

As part of the planification of the new drinking water well, TK CONSULT AG was assigned by the illwerke vkw AG to evaluate these questions using a newly developed and calibrated 3D groundwater model. The nearby reservoirs for pumping water pose the main potential risk. The required depth of pumping to avoid the impact of the reservoirs was evaluated using the groundwater model. Steady-state simulations for low, medium and high groundwater levels were conducted. In the future, the newly developed and calibrated 3D model could also be used to answer new hydrogeological questions for upcoming projects.