The pilot operation of the nuclear power plant (NPP) Temelín first block was started up in 2001 and of the second block in 2002. Since 1990, the systematic attention has been paid to the monitoring of the hydrosphere reference level in the NPP Temelín vicinity. The Temelín NPP waste water influence has been monitored and assessed since 2001. The monitoring has been focused especially on the tritium, strontium-90 and caesium-137 concentration changes in water, river bottom sediments, fish, and in the water plants biomass. The observed half-lives indicate that the strontium-90 and caesium-137 releases fully interfere with the residual contamination after the nuclear weapons tests and the Chernobyl accident in the last century. Only the tritium concentrations in water samples, taken in the Vltava River downstream from the NPP Temelín waste water outflow, show a measurable influence.