Coastal restoration is considered a key solution to counteract coastal degradation and mitigate climate change. In recent years, China’s coastal restoration projects have multiplied, with more than one billion US dollars spent during 2016-2019. Due to the sudden die-off of marsh vegetation in the Liaohe River Estuary, local managers have spent more than 30 million dollars to restore these salt marshes since 2015. However, these projects either failed or yielded limited results. Combining long-term remote sensing data to ground-based surveys, we found that salt marshes in the Liaohe River Estuary have experienced two dramatic diebacks separated by a recovery period, and the rapid changes in vegetation canopy were primarily driven by freshwater availability, especially river discharge. We suggest that mismatch between degradation drivers at the watershed-scale and restoration efforts at the local-scale hinders the success of coastal restorations. Efforts to restore these salt marshes will always be thwarted unless freshwater availability is replenished. Therefore, we propose a watershed-based solution, incorporating water replenishment from the river basin in estuarine restoration projects. Given the declining trends in river freshwater inputs in low-middle latitude coastlines, such wetland deterioration might also occur in many world's estuaries. Lessons from China’s large-scale coastal restoration projects can help other regions to avoid similar shortcomings, and improve our restoration practices before too many resources are lost.