The desalinated water supply and power production are managed by the Abu Dhabi Water and Electricity Authority (ADWEA). , it supplied 560.2 MiGD (million imperial gallons per day) of water, while the water demand for 2005–06 was estimated to be 511 MiGD. The Environment Agency of Abu Dhabi (EAD) states that groundwater is the most significant source of water, as well as desalinated potable water, and treated sewage effluent. At 40.6 MiGD, the Umm Al Nar storage is the largest water source for Abu Dhabi, followed by the rivers Shuweihat and Taweelah. With falling groundwater level and rising population density, Abu Dhabi faces a severely acute water shortage.