Originally, the delta used to receive almost all of the water from the Indus river, which has an annual flow of approximately , and is accompanied by of silt. Since the 1940s, dams, barrages and irrigation works have been constructed on the river Indus. The Indus Basin Irrigation System is the "largest contiguous irrigation system developed over the past 140 years" anywhere in the world. This has reduced the flow of water and by 2018, the average annual flow of water below the Kotri barrage was , and annual amount of silt discharged was estimated at . As a result, the 2010 Pakistan floods were considered "good news" for the ecosystem and population of the river delta as they brought much needed fresh water. Any further utilization of the river basin water is not economically feasible.