The U.S. Army Corps of Engineers is considering changing the operations of Berlin Lake, Lake Milton, Michael J Kirwan Reservoir, and Mosquito Creek Lake. The lakes in this study are all reservoirs, formed by dams. These models were constructed to simulate those operations and document possible water-quality effects in the lakes, the lake outflows, and the Mahoning River downstream of the lakes. This data release includes U.S. Army Corps of Engineers water-quality data and the input and output files from the mechanistic water-quality models (CE-QUAL-W2).

A mechanistic, biophysical water-quality model (CE–QUAL–W2) was developed and calibrated for Lake St. Croix, Wisconsin and Minnesota. The Lake St. Croix CE–QUAL–W2 model was simulated and calibrated using data collected from April through November 2013. Loads developed for the model were based on water-quality data collected by various agencies, including the U.S. Geological Survey (USGS). The calibrated model was used to evaluate good- and optimal-growth habitat availability for lake sturgeon using coldwater fish oxygen and thermal requirements, as part of the associated report, U.S. Geological Survey Scientific Investigations Report 2017-5157 (http://dx.doi.org/10.3133/SIR20175157).

A mechanistic, biophysical water-quality model (CE–QUAL–W2) was developed and calibrated for Lake St. Croix, Wisconsin and Minnesota. The Lake St. Croix CE–QUAL–W2 model was simulated and calibrated using data collected from April through November 2013. Loads developed for the model were based on water-quality data collected by various agencies, including the U.S. Geological Survey (USGS). The calibrated model was used to evaluate good- and optimal-growth habitat availability for lake sturgeon using coldwater fish oxygen and thermal requirements, as part of the associated report, U.S. Geological Survey Scientific Investigations Report 2017-5157 (http://dx.doi.org/10.3133/SIR20175157).

The U.S. Geological Survey (USGS), in cooperation with the St. Croix River Research Station – Science Museum of Minnesota, updated a previously developed CE-QUAL-W2 hydrodynamic and water-quality model of Madison Lake, Minnesota (Smith and others, 2017). The previous version simulated phytoplankton into four general algal communities or groups: (1) Bacillariophyta (diatoms) and Chrysophyta (chrysophytes); (2) Chlorophyta (green algae); (3) Cyanophyta (blue-green algae); and, (4) Haptophyta and Cryptophyta (flagellates). For the updated model, the Cyanophyta group (originally referred to as blue-green algae) has been divided into two groups: a nitrogen-fixing Cyanophyta group, generally representative of Anabaena, Dolichospermum, and Cylindrospermopsis, and a non-fixing, buoyant Cyanophyta group, generally representative of Planktothrix, Microcystis, and Woronichinia.

The U.S. Geological Survey (USGS), in cooperation with the St. Croix River Research Station – Science Museum of Minnesota, updated a previously developed CE-QUAL-W2 hydrodynamic and water-quality model of Madison Lake, Minnesota (Smith and others, 2017). The previous version simulated phytoplankton into four general algal communities or groups: (1) Bacillariophyta (diatoms) and Chrysophyta (chrysophytes); (2) Chlorophyta (green algae); (3) Cyanophyta (blue-green algae); and, (4) Haptophyta and Cryptophyta (flagellates). For the updated model, the Cyanophyta group (originally referred to as blue-green algae) has been divided into two groups: a nitrogen-fixing Cyanophyta group, generally representative of Anabaena, Dolichospermum, and Cylindrospermopsis, and a non-fixing, buoyant Cyanophyta group, generally representative of Planktothrix, Microcystis, and Woronichinia.

A hydrodynamic, water-temperature, and water-quality model (CE-QUAL-W2; Wells, 2020) of the Link-Keno reach of the Klamath River (Oregon) was used for calendar years 2006–15 to run a series of base and recirculation scenarios. These model runs were implemented to test alternative scenarios for routing some of the Klamath Straits Drain discharge into Ady Canal. The model scenarios were configured for baseline conditions and three different sets of recirculation scenarios, including the maximum year-round recirculation without discharge limits (scenario 1), limited year-round recirculation fixed by the current pipe flow configuration from Klamath Straits Drain into Ady Canal (scenario 2), and limited seasonal recirculation (May-September), also fixed by the current pipe flow configuration (scenario 3). For calendar years 2012–15, a separate CE-QUAL-W2 model for the Klamath Straits Drain was used in lieu of the Klamath Straits Drain as a tributary directly into the Link-Keno reach of the Klamath River CE-QUAL-W2 model. Original calibration and simulation of the Klamath Straits Drain model was documented in Sullivan and Rounds (2018). Original calibration and simulation of the Link-Keno reach of the Klamath River was documented in Sullivan and others (2011). These recirculation scenarios will be used by the United States Bureau of Reclamation to better understand the effects of recirculating Klamath Straits Drain discharge into Ady Canal on constituent loads of total nitrogen, total phosphorus, and the 5-day biochemical oxygen demand (BOD5).

A hydrodynamic, water-temperature, and water-quality model (CE-QUAL-W2; Wells, 2020) of the Link-Keno reach of the Klamath River (Oregon) was used for calendar years 2006–15 to run a series of base and recirculation scenarios. These model runs were implemented to test alternative scenarios for routing some of the Klamath Straits Drain discharge into Ady Canal. The model scenarios were configured for baseline conditions and three different sets of recirculation scenarios, including the maximum year-round recirculation without discharge limits (scenario 1), limited year-round recirculation fixed by the current pipe flow configuration from Klamath Straits Drain into Ady Canal (scenario 2), and limited seasonal recirculation (May-September), also fixed by the current pipe flow configuration (scenario 3). For calendar years 2012–15, a separate CE-QUAL-W2 model for the Klamath Straits Drain was used in lieu of the Klamath Straits Drain as a tributary directly into the Link-Keno reach of the Klamath River CE-QUAL-W2 model. Original calibration and simulation of the Klamath Straits Drain model was documented in Sullivan and Rounds (2018). Original calibration and simulation of the Link-Keno reach of the Klamath River was documented in Sullivan and others (2011). These recirculation scenarios will be used by the United States Bureau of Reclamation to better understand the effects of recirculating Klamath Straits Drain discharge into Ady Canal on constituent loads of total nitrogen, total phosphorus, and the 5-day biochemical oxygen demand (BOD5).