WATER QUALITY OF SELECTED WATERCOURSES IN ZASAVJE KAKOVOST VODE IZBRANIH VODOTOKOV V ZASAVJU AUTHORS/AVTORJA Lenart Štaut Research Centre of the Slovenian Academy of Sciences and Arts, Anton Melik Geographical Institute, Novi trg 2, SI – 1000 Ljubljana, Slovenia lenart.staut@zrc-sazu.si, https://orcid.org/0000-0003-0095-3920 dr. Tajan Trobec University of Ljubljana, Faculty of Arts, Department of Geography, Aškerčeva cesta 2, SI – 1000 Ljubljana, Slovenia tajan.trobec@ff.uni-lj.si, https://orcid.org/0000-0002-8784-4366 DOI: https://doi.org/10.3986/GV96102 UDC/UDK: 556.53:502(497.432) COBISS: 1.01 ABSTRACT Water quality of selected watercourses in Zasavje Good surface water quality is one of the most important goals of sustainable water management, along with sufficient quantity. This paper presents an analysis of water quality in the Medija, Trboveljščica and Boben watercourses in Zasavje (central Slovenia), which are not included in regular water quali- ty monitoring. Water quality was assessed on the basis of own field and laboratory analysis of selected physico-chemical parameters. In the period 2020-2021, 9 cyclical samplings were carried out at 16 loca- tions at different times of the year. It was found that the rivers Trboveljščica and Boben are significantly polluted, while the river Medija is in a much better condition. In the headwaters, water pollution is rela- tively low and mainly due to agricultural activities, which is also reflected in better water quality. In the lower reaches, the Boben and Trboveljščica rivers in particular are subject to significant pollution from industry and households, which are also the main sources of pollution. KEY WORDS watercourse pollution, surface water quality, physico-chemical water parameters, Boben, Medija, Trboveljščica IZVLEČEK Kakovost vode izbranih vodotokov v Zasavju Dobra kakovost površinskih voda je poleg njihovega ustreznega količinskega stanja eden ključnih ciljev trajnostnega upravljanja z vodami. V prispevku je predstavljena analiza kakovosti vode na zasavskih vodo- tokih Medija, Trboveljščica in Boben, ki niso vključeni v redni monitoring spremljanja kakovosti voda. Kakovost vode smo ocenjevali na podlagi lastnih terenskih in laboratorijskih analiz izbranih fizikalno- kemijskih parametrov. V obdobju 2020–2021 smo v različnih letnih časih izvedli 9 cikličnih vzorčenj na 16 lokacijah. Izkazalo se je, da sta Trboveljščica in Boben onesnažena, medtem ko je Medija v bistve- no boljšem stanju. V povirjih so obremenitve voda razmeroma majhne in večinoma pogojene s kmetijsko 29 Geografski vestnik 96-1, 2024, 29–63 Papers/Razprave PAPERS/RAZPRAVE vestnik 96_1_vestnik 82_1.qxd 12.3.2025 11:37 Page 29