During the 2018–20 water years, the U.S. Geological Survey, in cooperation with the Metropolitan Water Reclamation District of Greater Chicago, operated a continuous monitoring station on the Des Plaines River at Route 53 at Joliet, Illinois (USGS station 05537980), to better quantify nutrient and sediment loadings from the Greater Chicago Area to the Illinois River. This data release presents estimates of daily nitrate, suspended sediment, and phosphorus concentrations and uncertainty from that period. The concentration estimates are based on a combination of discrete sampling, continuously monitored surrogates, and surrogate regression (Bayesian imputation). The data release comprises a single csv file containing daily timeseries of streamflow, concentration, and uncertainty.

During water years 2016–2020, the U.S. Geological Survey, in cooperation with the Illinois Environmental Protection Agency, operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, suspended sediment, and phosphorus concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling data and surrogate regression (imputation). The data release comprises a single csv file containing daily timeseries of conentration and uncertainty for each monitoring station.

During water years 2016–2020, the U.S. Geological Survey, in cooperation with the Illinois Environmental Protection Agency, operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, suspended sediment, and phosphorus concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling data and surrogate regression (imputation). The data release comprises a single csv file containing daily timeseries of conentration and uncertainty for each monitoring station.

During water years 2016–2023 (a water year is the period from October 1 to September 30 and is designated by the year in which it ends), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station and a spreadsheet (xlsx) with yearly loads and streamflow for each individual site and total Illinois loads and streamflow. These methods are discussed in the most recent Illinois Nutrient Loss Reduction Strategy Biennial Report pages 25–26 ; see Biennial Report 2021–22 (2023). References Cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021, Continuous monitoring and Bayesian estimation of nutrient and sediment loads from Illinois watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092. [Also available at https://doi.org/10.3133/sir20215092]. Illinois Nutrient Loss Reduction Strategy Biennial Report 2021-22. (2023). Illinois Environmental Protection Agency and Illinois Department of Agriculture; Springfield, Illinois. University of Illinois Extension; Urbana-Champaign, Illinois. https://epa.illinois.gov/topics/water-quality/watershed-management/excess-nutrients/nutrient-loss-reduction-strategy.html.

During water years 2016–2022 (a water year begins on October 1 and ends on September 30), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a single comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station. Reference cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021, Continuous Monitoring and Bayesian Estimation of Nutrient and Sediment Loads from Illinois Watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092. [Also available at https://doi.org/10.3133/sir20215092].

During water years 2016–2022 (a water year begins on October 1 and ends on September 30), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a single comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station. Reference cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021, Continuous Monitoring and Bayesian Estimation of Nutrient and Sediment Loads from Illinois Watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092. [Also available at https://doi.org/10.3133/sir20215092].

During water years 2016–2022 (a water year begins on October 1 and ends on September 30), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a single comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station. Reference cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021, Continuous Monitoring and Bayesian Estimation of Nutrient and Sediment Loads from Illinois Watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092. [Also available at https://doi.org/10.3133/sir20215092].

During water years 2016–2021 (a water year begins on October 1 and ends on September 30 and is designated by the year in which it ends), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. These eight rivers are the Illinois River, Rock River, Little Wabash River, Kaskaskia River, Vermilion River, Embarras River, Big Muddy River, and Green River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a single comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station. These data supersede Hodson and others (2021b), which was based on data through water year 2020. Reference cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021a, Continuous Monitoring and Bayesian Estimation of Nutrient and Sediment Loads from Illinois Watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092, https://doi.org/3133/sir20215092. Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021b, Modeled nutrient and sediment concentrations from major rivers in Illinois based on continuous monitoring from October 1, 2015, through September 30, 2020: U.S. Geological Survey data release, https://doi.org/10.5066/P9MS8OIH.

During water years 2016–2021 (a water year begins on October 1 and ends on September 30 and is designated by the year in which it ends), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. These eight rivers are the Illinois River, Rock River, Little Wabash River, Kaskaskia River, Vermilion River, Embarras River, Big Muddy River, and Green River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a single comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station. These data supersede Hodson and others (2021b), which was based on data through water year 2020. Reference cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021a, Continuous Monitoring and Bayesian Estimation of Nutrient and Sediment Loads from Illinois Watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092, https://doi.org/3133/sir20215092. Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021b, Modeled nutrient and sediment concentrations from major rivers in Illinois based on continuous monitoring from October 1, 2015, through September 30, 2020: U.S. Geological Survey data release, https://doi.org/10.5066/P9MS8OIH.

The Illinois River receives nutrients from point and non-point runoff from upstream urban and agricultural areas. These excess nutrients could be contributing to harmful algal blooms in the Illinois River and its tributaries. Successfully mitigating the blooms requires an understanding of the underlying nutrient processes occurring in the river. Phosphorus is often the nutrient that limits phytoplankton growth and is a substantial concern in aquatic ecosystems because it can be stored long-term in the streambed sediment. Streambed sediment can act as a source or sink for phosphorus, and this dynamic is influenced by site conditions, including historic phosphorus loading and current stream water phosphorus concentrations. This study quantified streambed sediment phosphorus dynamics at 10 stream sites in the Illinois River Basin during the summer and fall of 2024.