It is a surprising fact that not all waterways on the Earth are mapped. Part of this is due to a legacy effect of modern cartographic effort, and resources and capacity by countries to undertake mapping programs. We are stepping in to fill that gap using high-res satellite imagery and digital elevation data to train computer vision models which we deploy in unmapped locations. The results are both beautiful and important, capturing up to 50 percent more of community needs and requests for infrastructure across nations in sub-Saharan Africa.