Society heavily depends on fertilizers to feed a growing world population. Part of the valuable nutrients in these fertilizers end up in surface waters, causing severe water quality problems, and are eventually lost into the oceans. Here, I propose Smart Nutrient Retention Networks (SNRNs) to tackle these challenges by employing self-reinforcing feedbacks between water quality and nutrient retention. I will develop a model to test and demonstrate smart management strategies to retain and recycle nutrients whilst improving water quality. In my project, I will perform case studies on multiple scales and assess the impact of global change on SNRNs.