Since the nineteenth century, the West has targeted the Senegal River Valley as an ideal location for environmental and agricultural improvement projects. In the early 1800s, French trading companies hoped to transform the Lower Senegal Valley into a massive plantation economy – one that would replace the devastating loss of Saint-Domingue to the Haitian Revolution. By the late nineteenth and early twentieth centuries, however, French colonizers shifted their focus from agricultural to energy, hoping that the establishment of a hydroelectric dam would stimulate the colonial economy and contribute to the growth of the extractive imperial economy. And, by the turn of the 21st century, international development institutions such as the World Bank, IMF, and USAID have once again turned to the Senegal River to construct a dam, though this time to alleviate famine in the region by providing farmlands with irrigation. In each case, these improvement projects not only failed to produce their intended results, but also helped to construct the stubborn and misguided narrative that the Sahel is in a continual state of environmental decline and crisis. In examining these wayward efforts to shape the riverain environment of the Senegal River Valley, this paper explores how Western science, technology, and innovation have ignored, and in some cases undermined, local systems of knowledge that have endured extended periods of ecological and climatic changes over time.