Lake Okeechobee, the second largest natural freshwater lake in the United States, had experienced a historical drought in 2007-2008 and the inflow to Lake Okeechobee has been reduced by 40% of the average daily mean between warm phase and cold phase due to the impact of Atlantic Multidecadal Oscillation in the past six decades. To cope with this water resources management problem, the US Army Corps of Engineers (USACE) proposed the largest national implementation plan of aquifer storage and recovery (ASR) project in the Kissimmee River Basin. Routine operation of ASR will deliver recovered water from ASR wells into the lake with different water quality parameters resulting in some concerns about the phosphorus stability issues at the sediment bed, which may lead to eutrophication problems. To explore the potential impacts of ASR operation on phosphorus stability in terms of adsorption, desorption, and diffusion processes, this research presented a systematic assessment based on five different mixing ratios between ASR water and lake water, and explored the sensitivity with respect to the chemical equilibrium between lake water and ASR water to predict the phosphorus stability changes in lake sediment. A series of lab-scale batch and column tests in support of a mechanistic modeling analysis provided a holistic chemical assessment as to how the phosphorus stability may be influenced by different mixing ratios. It led to an observation that the ratio of 1:10 between ASR water and lake water proved to be an optical ratio to avoid eutrophication and bring ecological benefits based on a suite of criteria.