On the northwest urban edge of Miami Dade County, the mining industry of the largest scale in Florida has existed for over 60 years. However, it is estimated to stop by 2050 as the reserves decline. As a consequence of limestone mining, more than 10,000 hectares of abandoned lakes will be left on the landscape. This project proposes land and water strategies to guide the future development of this post-mining lake area. It starts from the analysis on the existing hydrological, ecological, urban and mining conditions and define the existing situation as “boundary” that tends to establish static binary opposition between the urban and nature systems. Based on the site context, it proposes and explores “border” as a new urban edge condition that presents a dynamic interactive process in time. This process not only provides the possibility of regenerating potential of the post-mining area, but also increases resilience of the water system. What’s more, it creates conditions for the nature and urban systems to interact with each other and develop into an integrated whole.