AN ALTERNATIVE APPROACH FOR EVALUATION OF LAKE WATER-QUALITY - LAKE-SAPANCA - A CASE-STUDY FROM TURKEY

Lake Sapanca is the major water resource supplying drinking water as w ell as water for industrial and agricultural uses for one of the more industrialized areas of Turkey. Currently, the sustainability of its b eneficial use is an issue of concern. Initially the water quality in t he lake was classified according to the Turkish Regulations. With this conventional approach, a detailed water quality evaluation could not be achieved due to certain drawbacks, and this required the search for a new approach. Therefore, a more detailed classification was accompl ished by taking German Technical Standards as a basis that would lead to more usable and understandable classification necessary to promote a rational management strategy. Both classifications dictate that clas ses 1 and 2 may be used for water supply effectively. The detailed cla ssification indicates that at present water quality in the lake is ove rall of first class; however, it is tending towards Class 2, with the lake in a state of transition from oligotrophy to mesotrophy and the m ost critical issues being nutrient concentrations in the lake and land based nutrient sources. Copyright (C) 1996 IAWQ.