The major part of sediment deposits is situated in the localities, where Hnilec, Hornád, Belá and Opátka rivers flow into the water reservoir of Waterwork Ružín I. The analysis of sediment deposits for heavy metals (HM) showed the following results. Except for Cu, Co and Ni, the small tributary Belá creates sediment deposits with a low content of HM compared with the requirements of the Methodical Instruction of the Ministry of the Environment of the Slovak Republic No. 549/1998-2. The sediment deposits of the second small tributary Opátka have a similar composition, only the content of Cu exceeds the admissible concentration specified by the Instruction. The analyses of sediment deposits in the Hnilec river proved a high content of Cu and the increased content of Co and Ni. The sediment deposits of the Hornád river are heavily contaminated by HM, especially by Hg.