The USGS Integrated Water Availability Assessments (IWAAs) are designed to be a multi-extent, stakeholder driven, near real-time census and seasonal prediction of water availability for both human and ecological uses at regional and national extents. As part of the IWAAs program, the National Water Availability Assessment (National IWAAS) is intended to provide a periodic interpretive assessment of past, current, and future water demands compared to available supplies of clean water. The assessment will consider many of the factors that can influence the availability of water suitable for human and ecosystem uses including climate variability and change, and socioeconomic drivers such as changes in population, land use, and water withdrawals. This assessment will synthesize relevant model output from Integrated Water Prediction, IWAAs, and Water Use programs, among others, to address the current conditions, past changes (trends), projected future water availability throughout the nation.
