The power industry is one of the most water-consuming industries, therefore water management in this sector of the economy is a very important element of sustainable development. The analysis of the management of water streams at the surface water treatment plant (WTP) with decarbonization and ion exchange for water softening and demineralization was done. The main emphasis was placed on the effect of recycling of water used for the WTP’s own purposes on the quantity of water taken from the river and the quality of treated water. The article shows that water savings should also be sought at WTP in combined heat and power plants. Accurate distribution of used technological water streams and determination of their quality allows for the appropriate indication of the points of their return to the main technological line without additional treatment or only with the use of basic technological processes, e.g. sedimentation. In the analysed WTP, the quality of the backwash water returned after treatment was in terms of parameters, i.e. conductivity, hardness, alkalinity, CODKMnO4 and iron concentration, better than the quality of raw surface water. The reduction in the amount of water abstracted due to recycling of water treatment plant technological waters was about 8.3% (approximately 130 000 m3/year)