Benchmarking - Indicators of Sustainability of Thermal Groundwater Management

Abstract

The purpose of this study was to develop a methodology for comparison of different management entities to evaluate the sustainability of management of transboundary low- and intermediate temperature geothermal aquifers situated between Slovenia, Austria, Hungary and Slovakia, situated within the TRANSENERGY project area. Differences and similarities of actual management were investigated on a case study of five selected areas with various utilization conflicts: Bad Radkersburg-Hodoš (AT-SI), Danube basin (HU-SK), Komárno-Štúrovo / Komárom-Párkány (HU-SK) and Lutzmannsburg-Zsira area (HU-AT). We adjusted the “Lake Lemano” idea and defined 10 indicators: 1) Monitoring status, 2) Best available technology, 3) Energy efficiency, 4) Utilization efficiency, 5) Bathing efficiency, 6) Reinjection rate, 7) Status of water balance assessment, 8) Over-abstraction, 9) Quality of discharged waste thermal water and 10) Public awareness. Each indicator was first assessed by assigning relevant number of points to an individual source, and these were later weighted by the amount of abstracted thermal water, and averaged for the whole regional aquifer in an individual country. In order to provide sufficient and very detailed datasets, we performed detailed interviews with thermal water users and elaborated the User database, containing over 300 wells. The results reflect the long tradition of using thermal water for balneological purposes, and show very good utilization efficiency in the whole western part of the Pannonian Basin. In contrast to these positive results, poor monitoring status and water balance assessment, low energy efficiency, extremely low reinjection rate and insufficient public awareness materials show that significant actions are needed in all countries to improve management of these geothermal resources. There are still some weaknesses within this approach, especially regarding the evaluation procedure for bathing efficiency, quality of discharged waste thermal water and public awareness indicators. However, they were often not assessed due to lack of information. All information is available on website: http://transenergy-eu.geologie.ac.at/.