New USGS IWAAs product: National Integrated Water Availability Assessments concept map

The USGS National Integrated Water Availability Assessments (IWAAs) concept map is the first product to visualize a current, quantitative view of water availability at the national scale, providing an innovative, much-needed channel of water information. While the demonstration map is not ready for decision making, it can be used to compare an individual region’s current water storage to its historical storage (but it should not be used to compare one region’s storage to another region’s). “Natural water storage” sources include water present on the landscape such as standing water, snowpack, soil water, and shallow groundwater - but water in rivers or deep groundwater is not included.

In this first iteration of the National IWAAs concept map, the model focuses only on the natural water cycle and does not include human modification from reservoirs and withdrawals. As the model matures, additional hydrologic parameters will be produced and other indicators of water availability will be visualized, as well as water availability predictions. When combined with other water-availability indicators, this data will create new opportunities to study, forecast, and manage hydrologic resources.

The National Integrated Water Availability Assessments (IWAAs) concept map helps identify patterns in national water storage by comparing current conditions to historical values. In late fall 2019, the National IWAAs concept map visualized unusually wet conditions in the Northern Plains and Upper Midwest, unusually dry conditions in California that coincided with widespread wildfires, and wet conditions in the Southwest resulting from the remnants of Tropical Storm Raymond.

This map is a product of the USGS Integrated Water Availability Assessments, which are 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. The USGS IWAAs combine resources and knowledge gained from previous and ongoing USGS efforts such as focus area studies, regional groundwater availability studies, water use estimation, ecological water needs, and streamflow estimation. The IWAAs are designed to provide information to meet the goals of the National Water Census as established through the SECURE Water Act.