In this paper, we present a conceptual system architecture for real-time monitoring, predicting and controlling of invasive water hyacinth in freshwater bodies through the use of emerging technologies. The proposed system is planned to be deployed as one of the rescue efforts to preserve the fresh water lakes of Africa. The case study and the system presented in this paper are based on the Lake Tana, situated near the city of Bahir Dar, in Ethiopia. The rescuing efforts of Lake Tana so far focused on removal of the weed by hand and using harvesting machines. With the weed invasion doubling every two weeks, the current approaches will not be able to control the rapid invasion of the weed, which is causing considerable socioeconomic losses. The proposed system architecture employs networked underwater robots, aerial drones and other environmental sensors for better mapping of the weed coverage in real-time, predicting the floating paths of the weed, and learning the favourable environmental conditions of the lake for eradicating the invasive weed. The advantages of the proposed technical intervention lie not only in accurate monitoring and fast removal of the weed, but also in facilitating data collection for better understanding of the underlying environmental and chemical conditions that facilitate the rapid infestation and growth of the invasive weed.