Simulation of hydrodynamics, water quality, and lake sturgeon habitat volumes in Lake St. Croix, Wisconsin and Minnesota, 2013

Abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit https://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov.Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.Suggested citation: Smith, E.A., Kiesling, R.L., Ziegeweid, J.R., Elliott, S.M., and Magdalene, Suzanne, 2018, Simulation of hydro dynamics, water quality, and lake sturgeon habitat volumes in Lake St. Croix, Wisconsin and Minnesota, 2013: U.S. Geological Survey Scientific Investigations Report 2017-5157, 60 p., https://doi.org/10.3133/sir20175157. ISSN 2328-0328 (online) iii AcknowledgmentsThe cooperation of the National Park Service through the National Park Service-U.S. Geologi cal Survey WaterQuality Partnership program is gratefully acknowledged. This report presents a compilation of information supplied by several agencies and individuals. The authors would like to thank the U.S. DatumVertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).Elevation, as used in this report, refers to distance above the vertical datum. ix Supplemental InformationSpecific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 25 °C). Concentrations AbstractLake St. Croix is a naturally impounded, riverine lake that makes up the last 40 kilometers of the St. Croix River. Substantial land-use changes during the past 150 years, including increased agriculture and urban development, have reduced Lake St. Croix water-quality and increased nutrient loads delivered to Lake St. Croix. A recent (2012-13) total maximum daily load phosphorus-reduction plan set the goal to reduce total phosphorus loads to Lake St. Croix by 20 percent by 2020 and reduce Lake St. Croix algal bloom frequencies. The U.S. Geological Survey, in cooperation with the National Park Service, developed a two-dimensional, carbon-based, laterally averaged, hydrodynamic and water-quality model, CE-QUAL-W2, that addresses the interaction between nutrient cycling, primary production, and trophic dynamics to predict responses in the distribution of water temperature, oxygen, and chlorophyll a. Distribution is evaluated in the context of habitat for lake sturgeon, including a combination of temperature and dissolved oxygen conditions termed oxythermal habitat.The Lake St. Croix CE-QUAL-W2 model successfully reproduced temperature and dissolved oxygen in the lake longitudinally (from upstream to downstream), vertically, and temporally ove...

Integrating water quality monitoring and diatom community trends to determine landscape‐level change in protected lakes

“…T A B L E 1 Lake physical characteristics (adapted from VanderMeulen et al, 2016;SACN data from Robertson & Lenz, 2002;Smith et al, 2018). Note: Z max , maximum depth; GR, geometric ratio, where GR = lake area (in square meters) 0.25 /Z max (in meters).…”

Updates to the Madison Lake (Minnesota) CE–QUAL–W2 water-quality model for assessing algal community dynamics

“…Instead, surrogate water temperature datasets were constructed using a simple linear regression relation between daily air temperatures from the Mankato Regional Airport and daily water temperatures from the two inlet transducers measured in 2014 (Preud'homme and Stefan, 1992). The following regression equations were then applied to daily air temperature data collected from the Mankato Regional Airport in 2016 (National Climatic Data Center, 2016, 2018:…”

“…The qualitative sky cover parameter (that is, clear, scattered, broken, and overcast) was converted to an integer value ranging from 0 to 10: clear is 1, scattered (1/8 to 1/2 cloud coverage) is 5, and overcast is 10. All the required data were available at hourly intervals for the Mankato Regional Airport (U.S. Air Force station identification number 726585), which is less than (<) 12.5 kilometers (km) west of Madison Lake, from the Climate Data Online portal (National Climatic Data Center, 2016, 2018. Based on the latitude and longitude of the lake and the required meteorological inputs, evapotranspiration was included in the water balance as an internal CE-QUAL-W2 calculation.…”