ABSTRACT: The turbidity and less flow rate of Taşdelen and Karakulak springs in Istanbul are the most important problems occuring time by time. To establish the reasons of these problems» hydrogeoîogy of the vicinity and the water catchments of these springs have in vestigated. As the result of this investigation» too small distance between topographical surface and underground discharge points and also, the insufficient enviromental arrangements at the water catchment areas are established to be main reasons of the problem, The most available and practicable solutions taking into account the main reasons of problem have been pro posed in this paper