The U.S. Geological Survey is planning to intensively study 10 Integrated Water Science, IWS, basins — medium-sized watersheds of 10,000–20,000 square miles and underlying aquifers — throughout the United States over the coming decade to improve understanding of water availability in a wide range of environmental, hydrologic, and landscape settings. Each IWS basin will be studied for 10 years, serving as a regional focus for high-density monitoring and cutting-edge research used to better understand and predict water availability (quantity, quality, and use) that may be extended to a region and ultimately to the nation.
Next Generation Water Observing Systems
The Next Generation Water Observing Systems, NGWOS, component in the Illinois River Basin began in October 2020, Fiscal Year 2021, FY21, engaging basin stakeholders on priority issues. Nutrients and harmful algal blooms, or HABs, were selected as the primary focus for monitoring efforts within the basin. The USGS Central Midwest Water Science Center began deploying Next Generation monitoring equip- ment in FY21 to expand the existing water quality monitoring network from 2-13 continuous monitoring super gages in the basin. Super gages provide enhanced spatial and temporal resolution of nutrient cycle processes in the basin and function as testbeds for new HABs monitoring technologies. In FY22, NGWOS nutrient and HABs monitoring spanned scales and technologies ranging from the discrete sampling of low-order streams and ditches to remotely sensed water quality from satellite imagery.
During FY23/calendar year 2023, USGS will continue to operate and maintain the expanded monitoring network in the Illinois River Basin and begin compiling the new data.
More information about the Next Generation Water Observing System: Illinois River Basin | U.S. Geological Survey can be found at usgs.gov/mission-areas/water-resources/science/ next-generation-water-observing-system-illinois-river-basin.
Integrated Water Availability Assessments
The Integrated Water Availability Assessments, IWAAs, component in the Illinois River Basin began in FY22 and will leverage NGWOS monitoring with IWAAs modeling to increase understanding and make forecasts of water availability (groundwater and surface water) for human and ecological use under a changing climate. Initial IWAAs modeling efforts use existing models such as MODFLOW, SWAT, SPARROW, and CE-QUAL-W2 to examine nutrient cycle and HABs processes and their relation to system hydrology. The experience, knowledge, and insights gained from these initial modeling efforts will contribute to improving the following aspects of national hydrologic models:
- A better understanding of how to represent point and non-point sources of nutrients, nutrient transport processes, and the role of legacy nutrients;
- A better understanding of driving mechanisms for HABs in rivers and the drivers of algal toxin production.
In FY23, the USGS IWAAs team will continue to build out the initial modeling effort to identify data gaps and model issues early in the IWS 10-year basin cycle. This approach recognizes the shortcomings of existing models and will lead to the more efficient development of national-scale modeling, especially regarding temporally and spatially variable water quality constituents and loads to streams.
More information on IWAAs in the Illinois River Basin | U.S. Geological Survey can be found at usgs.gov/mission-areas/water-resources/science/integrated-water-availability-assessments-iwaas.
