In 1856, engineers finished building a levee system to protect farmland in the lower Rhône region from dangerous floods. This system was designed to control the river’s flow and prevent damage to agricultural areas. However, it had unexpected effects on the nearby Camargue delta, a wetland area known for its unique ecosystem. By channeling the river into a straight path, the levees isolated the delta from its natural sediment supply, which led to the area gradually sinking—a process known as subsidence. Before the levees were built, seasonal floods would carry nutrient-rich sediment downstream, depositing it in the Camargue delta. This natural process helped build up the land and counteract subsidence. However, the levees blocked this flow, redirecting the sediment directly to the river’s mouth and out to sea. As a result, the Camargue no longer received the materials it needed to maintain its elevation. Over the past 150 years, parts of the delta have sunk by several tens of centimeters, affecting the region’s stability and environment. The sinking of the Camargue has led to several environmental challenges. The soil has become more saline, making it less suitable for farming. Natural habitats, such as marshes and ponds, are shrinking, and some areas that were once used for agriculture are now too salty or unstable to support crops. Additionally, the region is becoming more vulnerable to rising sea levels, a problem worsened by climate change. To address these issues, scientists and engineers are testing new approaches, such as periodically opening the levees to allow controlled flooding and restoring wetlands to help manage water and sediment flow. These methods aim to reintroduce sediment to the delta in a measured way and create natural buffers that can absorb floodwaters and distribute sediments more evenly. While these strategies are still being tested on a small scale, they represent a shift in thinking about river management—focusing on working with natural processes rather than completely controlling them.