The study focused on simulating eutrophication in Shenzhen Reservoir using a specialized model. By analyzing water flows and quality data from 2009 to 2011, researchers successfully replicated the reservoir's hydrodynamics and identified eutrophication risks. Three scenarios were tested to combat the excess nutrients entering from Dongjiang: removing all nutrients, increasing water flow by 50%, and reducing nutrient input by half. Results showed that decreasing nutrients from Dongjiang and boosting water flow can lower chlorophyll-a levels by up to 46.3% in the reservoir, preventing water blooms despite ongoing eutrophication threats. Therefore, taking action to control nutrients can significantly enhance water quality in Shenzhen Reservoir and reduce the risk of harmful algae blooms.