This data set is a compilation of discrete and high frequency water quality data from sites on Allequash Creek in Wisconsin, and within the Allequash Creek watershed, for the water years (WY) 2019-2021.

This dataset includes discrete water quality and discharge data for three streams running through wetlands. Each location has two sites: one upstream from the wetland and one downstream from the wetland. Measurements were taken in 2010 and 2011 at West Twin Creek, AK; in 2019 and 2020 at Allequash Creek, WI; and in 2013, 2014, and 2017 at the Big Thompson River, CO. The upstream and downstream data from Allequash Creek and the Big Thompson River are from established USGS sites. At Allequash Creek, the downstream site is USGS 05357206 Allequash Creek Site No. 3 Nr Boulder Junction, WI, and the upstream site is USGS 5357205 Allequash Creek Near Sayner, WI. At the Big Thompson River, the downstream site is 402114105350101 Big Thompson Bl Moraine Park Nr Estes Park, CO, and the upstream site is USGS 402123105370401 Big Thompson R Nr Fern Lake Road, RMNP, CO. All measurements were recorded over water years (October 1 - September 30). Some of these data are also available in the National Water Information System by the United States Geological Survey, but are included here for dataset completeness. The overlapping data includes discharge at the Allequash Creek downstream gage and the Big Thompson River downstream gage, and specific conductivity at the Allequash Creek downstream gage, the Big Thompson River downstream gage, and the Big Thompson River upstream gage.

This dataset includes discrete water quality and discharge data for three streams running through wetlands. Each location has two sites: one upstream from the wetland and one downstream from the wetland. Measurements were taken in 2010 and 2011 at West Twin Creek, AK; in 2019 and 2020 at Allequash Creek, WI; and in 2013, 2014, and 2017 at the Big Thompson River, CO. The upstream and downstream data from Allequash Creek and the Big Thompson River are from established USGS sites. At Allequash Creek, the downstream site is USGS 05357206 Allequash Creek Site No. 3 Nr Boulder Junction, WI, and the upstream site is USGS 5357205 Allequash Creek Near Sayner, WI. At the Big Thompson River, the downstream site is 402114105350101 Big Thompson Bl Moraine Park Nr Estes Park, CO, and the upstream site is USGS 402123105370401 Big Thompson R Nr Fern Lake Road, RMNP, CO. All measurements were recorded over water years (October 1 - September 30). Some of these data are also available in the National Water Information System by the United States Geological Survey, but are included here for dataset completeness. The overlapping data includes discharge at the Allequash Creek downstream gage and the Big Thompson River downstream gage, and specific conductivity at the Allequash Creek downstream gage, the Big Thompson River downstream gage, and the Big Thompson River upstream gage.

Located in south-central Texas, the Geronimo Creek and Plum Creek watersheds have long been characterized by elevated nitrate concentrations. From April 2015 through March 2016, an investigation was done by the U.S. Geological Survey, in cooperation with the Guadalupe-Blanco River Authority (GBRA) and the Texas State Soil and Water Conservation Board (TSSWCB), to assess nitrate (as nitrogen) concentrations and to document possible sources of elevated nitrate as nitrogen in these two watersheds. Water-quality samples were collected from 20 groundwater, spring, and stream sites across the two watersheds, along with precipitation samples and wastewater treatment plant (WWTP) effluent samples from the Plum Creek watershed. Stream, spring, and groundwater samples were collected from both watersheds during four synoptic sampling events to characterize spatial and temporal variations in water quality and chemical loadings. Water-quality and quantity data from the wastewater treatment plants and stream discharge data were also considered. Samples were analyzed for major ions, selected trace elements, nutrients, stable isotopes of water and nitrogen isotopes. Data collected for this project was used to calculate selected chemical loadings and used in interpretation of sources of nitrate in both watersheds.

Located in south-central Texas, the Geronimo Creek and Plum Creek watersheds have long been characterized by elevated nitrate concentrations. From April 2015 through March 2016, an investigation was done by the U.S. Geological Survey, in cooperation with the Guadalupe-Blanco River Authority (GBRA) and the Texas State Soil and Water Conservation Board (TSSWCB), to assess nitrate (as nitrogen) concentrations and to document possible sources of elevated nitrate as nitrogen in these two watersheds. Water-quality samples were collected from 20 groundwater, spring, and stream sites across the two watersheds, along with precipitation samples and wastewater treatment plant (WWTP) effluent samples from the Plum Creek watershed. Stream, spring, and groundwater samples were collected from both watersheds during four synoptic sampling events to characterize spatial and temporal variations in water quality and chemical loadings. Water-quality and quantity data from the wastewater treatment plants and stream discharge data were also considered. Samples were analyzed for major ions, selected trace elements, nutrients, stable isotopes of water and nitrogen isotopes. Data collected for this project was used to calculate selected chemical loadings and used in interpretation of sources of nitrate in both watersheds.

This section of the data release supports the data used in models for the associated publication. The U.S. Geological Survey and the University of Wisconsin – Green Bay collected hydrologic and water-quality data to assess the effectiveness of agricultural conservation management practice (CMP) implementation at Mainstem Plum Creek (USGS site ID: 04084911) and West Plum Creek (USGS site ID: 04084927) in northeastern Wisconsin. Monitoring data from 2010–2020 at Mainstem Plum and 2013–2020 at West Plum were used to detect changes in hydrologic and water-quality responses during runoff events. Runoff events were defined by hydrographers and used to compute event loads and event flow-weighted mean concentrations of total phosphorus and total suspended solids – all of which are included in this data release. The data included in this release serve as model inputs for the associated model archive. Models in the associated archive were used to assess changes in water quality between two time periods (“initial” and “post-CMP implementation”) while controlling for environmental factors, such as weather and the conditions preceding events to elucidate water-quality changes more directly associated with CMP implementation.

This section of the data release supports the data used in models for the associated publication. The U.S. Geological Survey and the University of Wisconsin – Green Bay collected hydrologic and water-quality data to assess the effectiveness of agricultural conservation management practice (CMP) implementation at Mainstem Plum Creek (USGS site ID: 04084911) and West Plum Creek (USGS site ID: 04084927) in northeastern Wisconsin. Monitoring data from 2010–2020 at Mainstem Plum and 2013–2020 at West Plum were used to detect changes in hydrologic and water-quality responses during runoff events. Runoff events were defined by hydrographers and used to compute event loads and event flow-weighted mean concentrations of total phosphorus and total suspended solids – all of which are included in this data release. The data included in this release serve as model inputs for the associated model archive. Models in the associated archive were used to assess changes in water quality between two time periods (“initial” and “post-CMP implementation”) while controlling for environmental factors, such as weather and the conditions preceding events to elucidate water-quality changes more directly associated with CMP implementation.

This data release contains eight datasets and metadata related to streamwater constituent load estimation and E. coli bacteria concentration predictions at 15 watersheds in DeKalb County, Georgia for 2012 to 2016 (the water-quality model calibration data goes through 9/22/2017 and the water-quality assurance samples goes through 11/7/2017). Loads were estimated for 15 constituents: biochemical oxygen demand, chemical oxygen demand, total suspended solids, suspended sediment concentration, total nitrogen, total nitrate plus nitrite, total phosphorus, dissolved phosphorus, total organic carbon, total calcium, total magnesium, total copper, total lead, total zinc, and total dissolved solids. The data release includes the following eight datasets: (1) daily base-flow separation results that were used as explanatory variables in the load estimation models; (2) water-quality assurance sample concentrations; (3) laboratory standard reference sample concentrations; (4) water-quality outliers that were excluded from the calibration datasets used in regression models for estimating streamwater constituent loads and E. coli bacteria concentrations; (5) calibration datasets containing explanatory variables for modeling constituent loads; (6) model coefficients and model diagnostic statistics used to estimate streamwater constituent loads, including portable document format files (pdf) with reports and plots for evaluating model fits; (7) time-step data used for estimating loads from the model coefficients; and (8) annual and period of record streamwater constituent load and yield estimates, including the 95-percent confidence intervals of the estimates.

Comma separated values for monthly water chemistry data and water quality field parameters, Yellowstone River at Corwin Springs