A water reservoir is a large natural or artificial lake used to store water for various purposes, such as drinking, irrigation, and hydroelectric power generation. These reservoirs can be created by damming rivers or by collecting rainwater in designated areas. They play a crucial role in managing water supply and ensuring availability during dry periods. Reservoirs also help in flood control by capturing excess rainwater and releasing it gradually. Additionally, they provide recreational opportunities, such as fishing and boating, and support local ecosystems by maintaining habitats for various wildlife species.