Monitoring of water quality in the state network was begun by the CHMI in 1963 as part of measures designed to improve water quality in streams, which significantly worsened as a result of human activity. The aim is to gain information necessary for the evaluation of the state and development of the hydrosphere and for the protection of potable water sources. At the present time there is on the territory of the Czech Republic in the state network of water quality monitoring of streams placed on streams significant from the water resources point of view 257 profiles, where there are 12 times a year sample collections of surface water made for the analyses of basic physical - chemical parameters, heavy metals, specific organic matters, biological and microbiological parameters, and further 85 profiles for radiochemical analyses. In the state network there is pilot-wise included 45 profiles of complex water quality monitoring, in which individual pollutants are being monitored not only in water, but also in suspended solids, in sediments and in biomass. The aim is to gain a picture of the river as a complex ecosystem.
The department solves the problem of suspended solids and river sediments, which includes the quantitative evaluation of suspended solids in the network of watergauging stations with daily monitoring of suspended solids, qualitative evaluation of suspended solids and river sediments in the network of complex monitoring of surface water quality and radiochemical monitoring.