MARMARA GEOGRAPHICAL REVIEW, sa.31, ss.48-81, 2015 (ESCI)
Located on Cayagzi Kocaeli Plateau (Riva) basin has a catchment area of approximately 859 km(2) like (Figure 1). Geological, geomorphologic sense, forming a basin unit area, also meet one of the major watersheds in Istanbul. Basin, which drains Cayagzi (Riva) River, in southeastern stemming from Kocaeli Province territory, in the north Cayagzi (Riva) is poured into the Black Sea near the Cayagzi (Riva) village. The middle section of the settled Omerli Reservoir Watershed, including primarily Aanadol Collar, Istanbul meets the water needs of the city. Basin today and in the future in a sustainable way for the use of the opportunities offered by the natural conditions and the analysis of risk is important.