The USGS Integrated Water Availability Assessments (IWAAs) are designed to be a multi-extent, 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 periodic interpretive assessments 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. The assessments will synthesize relevant model output and observational [...]
Summary
The USGS Integrated Water Availability Assessments (IWAAs) are designed to be a multi-extent, 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 periodic interpretive assessments 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. The assessments will synthesize relevant model output and observational data 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.
An assessment of conditions during the 2010-2020 period was completed and published in January 2025. The professional paper (Stets and others, 2025) includes chapters about Water Supply (Gorski and others, 2025), Water Quality (Erickson and others, 2025), Water Use (Medalie and others, 2025), Future Water Resources (Scholl and others, 2025), and Integrated Water Availability (Stets and others, 2025). Data releases published in support of these analyses are in the folder of this page titled, “Assessment of conditions, 2010-2020”. Software releases published in support of these analyses are hosted here National Water Availability Assessment 1a releases · GitLab.
The National Water Availability Assessment Project is part of the Water Availability and Use Science Program and the National Water Quality Program.
