My thesis is divided into two main parts. The first part is focused on the properties of phosphorous and nitrogen that are most important in the eutrophication process, while the second part of the thesis presents the specifics of the water basin Jezero in Smarjeske Toplice. The first part of the thesis describes the problem of pollution with nutrients in the aquatic environment - eutrophication. Eutrophication is caused by excessive nutrient concentrations in the aquatic environment, which is limited by the lack of one of the two presented nutrients in this thesis. The thesis is focused on two nutrients, namely phosphorus and nitrogen. The thesis presents the basic properties for phosphorus and nitrogen and the circulation of these two nutrients in the environment. It also lists and describes the main anthropogenic activities, which contribute the largest share of these nutrients into the environment. In its next chapters the thesis presents the chemical and biological processes, removal of phosphorus and nitrogen, and some common technologies developed for the purpose of disposing these two nutrients from water. Then it presents some assumptions and actions for reducing the impact of these two nutrients on the environment in the future. The first part of the thesis is concluded with the use of nutrients in Slovenian agriculture in order to improve the productivity of its agricultural land. The second part of the thesis delivers a presentation of the largest water basin in the Dolenjska region – water basin Jezero in Šmarješke Toplice. It describes the legislation, regarding water resources on the European, state and municipal level. It also presents the ways of determining water protection areas, their different variations and its limits and restrictions. There is also a calculation of nutrient concentration in the underground waters in this specific area. The final part of the thesis is a product of collaboration with Komunala Novo mesto. It presents their plans for improving quantitative and qualitative properties of the water that is pumped from the water basin Jezero.