Why is saltwater intrusion a common problem in heavily populated coastal areas?

Saltwater intrusion is common in heavily populated coastal areas due to the excessive withdrawal of groundwater for agricultural, industrial, and residential use. This over-extraction reduces the freshwater aquifer pressure, allowing saltwater from the ocean to migrate inland and contaminate freshwater supplies. Additionally, rising sea levels associated with climate change exacerbate this issue, further compromising freshwater resources. As a result, communities face challenges in maintaining safe drinking water and sustainable agriculture.