Wetlands are of utmost importance in the sense of protecting the natural ecological balance of the environment. It is possible to improve the water quality of wetlands, which are located in coastal areas like river deltas and lakes without disturbing the ecological balance through rehabilitation and by controlling. However, many wetlands in the world have so far been dried and converted to agricultural areas due to insufficient knowledge of their ecological value. Such an understanding was also held as true in Turkey and most of its wetlands have been converted to agricultural land till recent years. An example of such an occurrence and modifications within years are observed in the delta of the Kizilirmak River, which is the longest river of Turkey ending in the Black Sea. The past and present situation of the Kizilirmak delta will be investigated in this paper together with the changes in water quality. An evaluation of the water quality of the river and of lakes within the delta is done based on available previous data and on the final findings of water quality measurements conducted within the framework of this study.