The anti-ecological practices induced by industrialization and urbanization in Turkey since the 1970s have had hazardous effects on the ecosystems of the Ergene River. As a petition addressing the General Directorate of State Hydraulic Works ((Devlet Su İşleri Genel Müdürlüğü, DSİ) indicates, industry-related water pollution was recorded as early as 1978. This study aims to focus on the pollution of the Ergene River as an outcome of the hegemonic cosmology in Turkey. The reasons behind the problems of the Ergene River Basin are not entirely different from the other twenty-five river basins of Turkey, but its proximity to Istanbul, the country’s most populous city, has resulted in a more direct negative experience of the hegemonic cosmology.