The bifurcation of the Euphrates caused by the so-called Hindiyya-channel that was constructed in the late 18th / early 20th centuries with the aim to bring water to Najaf became one of the prolonged problems tormenting the Ottoman administration in Iraq throughout the late Ottoman period. It reduced the cultivable area around Hilla that had formed an important tax revenue for the Ottoman governors in Baghdad and unsettled the tribal balance in the area. Various Ottoman governors attempted to solve the problem either by seeking to re-establish the hydrological balance between what had become the two branches of the Euphrates, by militarily checking the tribal movements that resulted from the shifting of the river's main course or by trying to exploit them politically. What had been a local (however important) problem in the first half of the 19th century became increasingly the project of a general reconstruction of Iraq's hydrological geography. While until the 1860s the Ottoman administration had almost exclusively employed local technical knowledge in their hydraulic engineering the Ottomans increasingly came to rely on European-inspired engineering that ushered in the grandiose projects of the famous British engineer William Willcocks in the beginning of the 20th century. The paper argues that the resort to imported “scientific methods” of engineering enlarged not only the social distance between the Ottomans and the indigenous population but also failed to bring the desired ultimate solution to the economic, social and environmental problems of the region. In this respect the history of the Hindiyya-channel may be read as a case study for some of the major problems and predicaments of Ottoman modernization policy. The paper is based on contemporary Ottoman and European printed publications and on British, French and German as well as Ottoman archival material.