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At least 73 records · Page 4Linked to original sources
USGS2022

The role of hydraulic and geomorphic complexity in predicting invasive carp spawning potential: St. Croix River, Minnesota and Wisconsin, United States

Since they were first introduced to the United States more than 50 years ago, invasive carp have rapidly colonized rivers of the Mississippi River Basin, with detrimental effects on native aquatic species. Their continued range expansion, and potential for subsequent invasion of the Great Lakes, has led to increased concern for the susceptibility of as-yet uncompromised lotic and lentic systems in the central United States. Because invasive carp eggs and larvae must drift in the river current for the first several days following spawning, numerical drift modeling has emerged as a useful technique for determining whether certain river systems and reaches have the potential to support suspension-to-hatching survival of invasive carp eggs, a critical first step in recruitment. Here we use one such numerical modeling approach, the Fluvial Egg Drift Simulator (FluEgg), to estimate bighead carp ( Hypophthalmichthys nobilis ) egg hatching success and larval retention in a 47.8-kilometer (km) reach of the multi-thread St. Croix River, Minnesota and Wisconsin, United States. We explore three approaches for obtaining the hydraulic data required by FluEgg, parameterizing the model with either (a) field hydraulic data collected within the main channel during a high-flow event, or hydraulic data output from a one-dimensional hydrodynamic model with both (b) steady, and (c) unsteady flows. We find that the three approaches, along with the range of water temperatures and discharge used in simulations, produce vastly different predictions of streamwise transport and in-river egg hatching probability (0% for field data, 0 to 96% for steady-state hydraulic modeling, and 1.8 to 65% for unsteady modeling). However, all FluEgg simulations, regardless of the source of hydraulic data, predicted that no larvae reach the gas bladder inflation stage within the study reach where nursery habitat is abundant. Overall, these results indicate that the lower St. Croix River is suitable for invasive carp spawning and egg suspension until hatching for a range of discharge and water temperatures. These results highlight the role of complex channel hydraulics and morphology, particularly multi-thread reaches, and their inclusion in ecohydraulic-suitability modeling to determine susceptibility of river systems for invasive carp reproduction. Our work also emphasizes the scientific value of multi-dimensional hydrodynamic models that can capture the spatial heterogeneity of flow fields in geomorphically complex rivers. This work may help to guide management efforts based on the targeted monitoring and control and improve invasive carp egg and larvae sampling efficiency.

Minnesota, Wisconsin↗
USGS2026

Urban stormwater treatment using biofiltration—Variable performance across solids, nutrients, major ions, and metals

Urban runoff from streets and parking lots carries pollutants that degrade receiving waters. Green infrastructure, such as biofilters, is increasingly used to treat this runoff by mimicking natural hydrologic processes. The U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District, evaluated a biofilter receiving roadway runoff from an industrial area in Milwaukee, Wisconsin, over a 3-year period (2022–24). Paired inlet and outlet samples were analyzed for changes in runoff volume, peak discharge, and concentrations of solids, nutrients, major ions, and metals. The biofilter reduced runoff volume by 86 percent and peak discharge by 92 percent, with substantial reductions in total suspended solids (99 percent), total phosphorus (86 percent), and particulate metals (greater than 80 percent for most analytes). However, dissolved constituents showed variable performance; dissolved phosphorus and several metals exhibited net export, likely influenced by media composition, redox conditions, and winter road salt inputs. Sodium export, despite stable chloride loads, suggests cation exchange and seasonal release dynamics. These findings highlight limitations of conventional biofilter designs for dissolved pollutants and underscore the need for improved media, vegetation management, and consideration of winter deicing practices.

Wisconsin↗
USGS2006

Estimates of Shear Stress and Measurements of Water Levels in the Lower Fox River near Green Bay, Wisconsin

Turbulent shear stress in the boundary layer of a natural river system largely controls the deposition and resuspension of sediment, as well as the longevity and effectiveness of granular-material caps used to cover and isolate contaminated sediments. This report documents measurements and calculations made in order to estimate shear stress and shear velocity on the Lower Fox River, Wisconsin. Velocity profiles were generated using an acoustic Doppler current profiler (ADCP) mounted on a moored vessel. This method of data collection yielded 158 velocity profiles on the Lower Fox River between June 2003 and November 2004. Of these profiles, 109 were classified as valid and were used to estimate the bottom shear stress and velocity using log-profile and turbulent kinetic energy methods. Estimated shear stress ranged from 0.09 to 10.8 dynes per centimeter squared. Estimated coefficients of friction ranged from 0.001 to 0.025. This report describes both the field and data-analysis methods used to estimate shear-stress parameters for the Lower Fox River. Summaries of the estimated values for bottom shear stress, shear velocity, and coefficient of friction are presented. Confidence intervals about the shear-stress estimates are provided.

Scientific Investigations Report↗
USGS2010

Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow. Lastly, it describes several categories of limitations and discusses ways of extending the regional model to address issues at the local scale. Results of the simulations portray a regional groundwater-flow system that, over time, has largely maintained its natural predevelopment configuration but that locally has been strongly affected by well withdrawals. The quantity of rainfall in the Lake Michigan Basin and adjacent areas supports a dense surface-water network and recharge rates consistent with generally shallow water tables and predominantly shallow groundwater flow. At the regional scale, pumping has not caused major modifications of the shallow flow system, but it has resulted in decreases in base flow to streams and in direct discharge to Lake Michigan (about 2 percent of the groundwater discharged and about 0.5 cubic foot per second per mile of shoreline). On the other hand, well withdrawals have caused major reversals in regional flow patterns around pumping centers in deep, confined aquifers - most noticeably in the Cambrian-Ordovician aquifer system on the west side of Lake Michigan near the cities of Green Bay and Milwaukee in eastern Wisconsin, and around Chicago in northeastern Illinois, as well as in some shallow bedrock aquifers (for example, in the Marshall aquifer near Lansing, Mich.). The reversals in flow have been accompanied by large drawdowns with consequent local decrease in storage. On the west side of Lake Michigan, groundwater withdrawals have caused appreciable migration of the deep groundwater divides. Before the advent of pumping, the deep Lake Michigan groundwater-basin boundaries extended west of the Lake Michigan surface-water basin boundary, in some places by tens of miles. Over time, the pumping centers have replaced Lake Michigan as the regional sink for the deep flow system. The regional model is intended to support the framework pilot study of water availability and use for the Great Lakes Basin (Reeves, in press).

Illinois, Indiana, Michigan, Wisconsin↗
USGS2013

Effects of best-management practices in Bower Creek in the East River priority watershed, Wisconsin, 1991-2009

Hydrologic and water-quality data were collected at Bower Creek during the periods before best-management practices (BMPs), and after BMPs were installed for evaluation of water-quality improvements. The monitoring was done between 1990 and 2009 with the pre-BMP period ending in July 1994 and the post-BMP period beginning in October 2006. BMPs installed in this basin included streambank protection and fencing, stream crossings, grade stabilization, buffer strips, various barnyard-runoff controls, nutrient management, and a low degree of upland BMPs. Water-quality evaluations included base-flow concentrations and storm loads for total suspended solids, total phosphorus, and ammonia nitrogen. The only reductions detected between the base-flow samples of the pre- and post-BMP periods were in median concentrations of total phosphorus from base-flow samples, but not for total suspended solids or dissolved ammonia nitrogen. Differences in storm loads for the three water-quality constituents monitored were not observed during the study period.

Wisconsin↗
USGS2022

Water-surface profile maps for the Mississippi River near Prairie Island, Minnesota, 2019

Digital water-surface profile maps for a 14-mile reach of the Mississippi River near Prairie Island, Minnesota, from the confluence of the St. Croix River at Prescott, Wisconsin, to upstream from the U.S. Army Corps of Engineers Lock and Dam No. 3 (U.S. Army Corps of Engineers National Inventory of Dams number MN00595) in Welch, Minnesota, were created by the U.S. Geological Survey (USGS) in cooperation with the Prairie Island Indian Community in the State of Minnesota. The water-surface profile maps depict estimates of the areal extent and depth of water inundation corresponding to selected water levels (stages) at the USGS streamgage Mississippi River at Prescott, Wisconsin (USGS station number 05344500). Current conditions for estimating near-real-time areas of inundation by use of USGS streamgage information may be obtained from the National Water Information System on the internet at https://doi.org/10.5066/F7P55KJN . In this study, water-surface profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relations at the USGS streamgage Mississippi River at Prescott, Wisconsin (USGS station number 05344500). The hydraulic model was then used to determine four water-surface profiles for stream stages at 37.00, 39.00, 40.00, and 41.00 feet (ft) referenced to the streamgage datum and ranging from bankfull to approximately 2 ft below the highest recorded stage at the streamgage, which is 43.11 ft. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from light detection and ranging data having a 0.35-ft vertical and 1.97-ft root mean square error horizontal resolution) in order to delineate the area inundated at each stage. The combination of maps provided in this report and real-time stage data from the upstream USGS streamgage provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post flood recovery efforts.

Minnesota↗
USGS2004

Water quality, hydrology, and the effects of changes in phosphorus loading to Pike Lake, Washington County, Wisconsin, with special emphasis on inlet-to-outlet short-circuiting

Pike Lake is a 459-acre, mesotrophic to eutrophic dimictic lake in southeastern Wisconsin. Because of concern over degrading water quality in the lake associated with further development in its watershed, a study was conducted by the U.S. Geological Survey from 1998 to 2000 to describe the water quality and hydrology of the lake, quantify sources of phosphorus including the effects of short-circuiting of inflows, and determine how changes in phosphorus loading should affect the water quality of the lake. Measuring all significant water and phosphorus sources and estimating lesser sources was the method used to construct detailed water and phosphorus budgets. The Rubicon River, ungaged near-lake surface inflow, precipitation, and ground water provide 55, 20, 17, and 7 percent of the total inflow, respectively. Water leaves the lake through the Rubicon River outlet (87 percent) or by evaporation (13 percent). Total input of phosphorus to the lake was about 3,500 pounds in 1999 and 2,400 pounds in 2000. About 80 percent of the phosphorus was from the Rubicon River, about half of which came from the watershed and half from a waste-water treatment plant in Slinger, Wisconsin. Inlet-to-outlet short-circuiting of phosphorus is facilitated by a meandering segment of the Rubicon River channel through a marsh at the north end of the lake. It is estimated that 77 percent of phosphorus from the Rubicon River in monitoring year 1999 and 65 percent in monitoring year 2000 was short-circuited to the outlet without entering the main body of the lake. Simulations using water-quality models within the Wisconsin Lake Model Suite (WiLMS) indicated Pike Lake's response to 13 different phosphorus-loading scenarios. These scenarios included a base 'normal' year (2000) for which lake water quality and loading were known, six different percentage increases or decreases in phosphorus loading from controllable sources, and six different loading scenarios corresponding to specific management actions. Model simulations indicate that a 50-percent reduction in controllable loading sources would be needed to achieve a mesotrophic classification with respect to phosphorus, chlorophyll a, and Secchi depth (an index of water clarity). Model simulations indicated that short-circuiting of phosphorus from the inlet to the outlet was the main reason the water quality of the lake is good relative to the amount of loading from the Rubicon River and that changes in the percentage of inlet-to-outlet short-circuiting have a significant influence on the water quality of the lake.

Wisconsin↗
USGS2022

Simulation of regional groundwater flow and groundwater/lake interactions in the Central Sands, Wisconsin

A multiscale, multiprocess modeling approach was applied to the Wisconsin Central Sands region in central Wisconsin to quantify the connections between the groundwater system, land use, and lake levels in three seepage lakes in Waushara County, Wisconsin: Long and Plainfield (The Plainfield Tunnel Channel Lakes), and Pleasant Lakes. A regional groundwater-flow model, the Newton Raphson formulation of the U.S. Geological Survey modular finite-difference flow model groundwater-modeling package (MODFLOW-NWT), centered on the lakes, was used to extend regional surface-water boundaries to provide boundary conditions for two focused inset models, in the hydrologic simulation modeling package (MODFLOW 6), at higher resolution around the lakes. Land use and groundwater use were simulated at a regional scale using the Soil Water Balance model, which provided recharge and water-use boundary conditions for the MODFLOW models. Agricultural irrigation is the primary groundwater use in the area. Land and groundwater-use scenarios representing no irrigation, current (2018) irrigation, and potential future irrigation were simulated with the groundwater-flow model and the lake levels over a 38-year representative climate period.

Wisconsin↗
USGS2023

Response in the water quality of Delavan Lake, Wisconsin, to changes in phosphorus loading—Setting new goals for loading from its drainage basin

During 1989–92, an extensive rehabilitation project was completed in and around Delavan Lake, Wisconsin, to improve the lake’s water quality. However, in 2016, the lake was listed by the Wisconsin Department of Natural Resources as impaired for excessive algal growth (high chlorophyll a concentrations), and high phosphorus input was listed as its likely cause. In addition, the recent (2017–21) mean summer water clarity (as measured with a Secchi disk) was shallower than the goal set by the community (3.0 meters). Based primarily on flow and water-quality data collected in Jackson Creek, which is the main tributary of the lake, the mean annual phosphorus loading to the lake during water years (WYs) 2017–21 was 6,570 kilograms per year (kg/yr), and 306 kg/yr came from uncontrollable sources (atmospheric deposition and groundwater). Phosphorus loading during these years was about 48 percent higher than the long-term mean loading from WY 1984 to WY 2021. Based on results from Canfield-Bachmann phosphorus models, Carlson trophic state index relations, and the Jones and Bachmann chlorophyll a relation, external phosphorus loading would need to be decreased from 6,570 to 5,270 kg/yr (a 21-percent reduction in the potentially controllable external phosphorus load from the base period of WYs 2017–21) for chlorophyll a concentrations greater than 20 micrograms per liter to be detected no more than 5.0 percent of the time (the Wisconsin Department of Natural Resources criterion for chlorophyll a impairment for the lake). Based on Carlson trophic state index relations, external loading would need to be decreased from 6,570 to 4,380 kg/yr (a 35-percent reduction in the potentially controllable external phosphorus load) for summer mean Secchi depths to increase to 3.0 meters. Therefore, for Delavan Lake to reach the water-quality criteria for impairment and the goals for all three water-quality constituents, a 35-percent reduction in the potentially controllable phosphorus load is needed, which equates to a reduction in total phosphorus loading from 6,570 to 4,380 kg/yr. A 35-percent reduction in phosphorus loading to improve the water quality of Delavan Lake is less than the 49-percent reduction in phosphorus loading required for the area near Delavan Lake to improve the water quality of the Rock River and its tributaries indicated in the Rock River total maximum daily load.

Wisconsin↗
USGS2004

Effectiveness of a pressurized stormwater filtration system in Green Bay, Wisconsin: A study for the environmental technology verification program of the U.S. Environmental Protection Agency

A pressurized stormwater filtration system was installed in 1998 as a stormwater-treatment practice to treat runoff from a hospital rooftop and parking lot in Green Bay, Wisconsin. This type of filtration system has been installed in Florida citrus groves and sewage treatment plants around the United States; however, this installation is the first of its kind to be used to treat urban runoff and the first to be tested in Wisconsin. The U.S. Geological Survey (USGS) monitored the system between November 2000 and September 2002 to evaluate it as part of the U.S. Environmental Protection Agency's Environmental Technology Verification Program. Fifteen runoff events were monitored for flow and water quality at the inlet and outlet of the system, and comparison of the event mean concentrations and constituent loads was used to evaluate its effectiveness. Loads were decreased in all particulate-associated constituents monitored, including suspended solids (83 percent), suspended sediment (81 percent), total Kjeldahl nitrogen (26 percent), total phosphorus (54 percent), and total recoverable zinc (62 percent). Total dissolved solids, dissolved phosphorus, and nitrate plus nitrite loads remained similar or increased through the system. The increase in some constituents was most likely due to a ground-water contribution between runoff events. Sand/silt split analysis resulted in the median silt content of 78 percent at the inlet, 87 percent at the outlet, and 3 percent at the flow splitter.

Wisconsin↗
USGS2022

Continuous monitoring of nutrient and sediment loads from the Des Plaines River at Route 53 at Joliet, Illinois, water years 2018–20

The Des Plaines River in southern Wisconsin and northern Illinois is the principal conduit for the discharge of wastewater effluent and stormwater runoff from the greater Chicago metropolitan area. In November 2017, the U.S. Geological Survey, in cooperation with the Metropolitan Water Reclamation District of Greater Chicago, installed a continuous monitoring station to measure water quality and streamflow in the Des Plaines River at Joliet, Illinois. Surrogate models encompassing continuous data and discrete water-quality samples were used to estimate loads of nitrate, total phosphorus, and suspended sediment. Comparisons to other major rivers in Illinois show that the Des Plaines River is a substantial contributor to statewide loading estimates for nitrate and total phosphorus but only a minor contributor to suspended sediment. Future loading estimates of total phosphorus could include more research into the effects of combined sewage overflows because these effects likely increased model uncertainty. The results in this report document current loadings and provide a baseline from which to assess future water-quality management decisions.

Illinois↗
USGS2005

Coral disease and health workshop: Coral histopathology II, July 12-14, 2005

The health and continued existence of coral reef ecosystems are threatened by an increasing array of environmental and anthropogenic impacts. Coral disease is one of the prominent causes of increased mortality among reefs globally, particularly in the Caribbean. Although over 40 different coral diseases and syndromes have been reported worldwide, only a few etiological agents have been confirmed; most pathogens remain unknown and the dynamics of disease transmission, pathogenicity and mortality are not understood. Causal relationships have been documented for only a few of the coral diseases, while new syndromes continue to emerge. Extensive field observations by coral biologists have provided substantial documentation of a plethora of new pathologies, but our understanding, however, has been limited to descriptions of gross lesions with names reflecting these observations (e.g., black band, white band, dark spot). To determine etiology, we must equip coral diseases scientists with basic biomedical knowledge and specialized training in areas such as histology, cell biology and pathology. Only through combining descriptive science with mechanistic science and employing the synthesis epizootiology provides will we be able to gain insight into causation and become equipped to handle the pending crisis. One of the critical challenges faced by coral disease researchers is to establish a framework to systematically study coral pathologies drawing from the field of diagnostic medicine and pathology and using generally accepted nomenclature. This process began in April 2004, with a workshop titled Coral Disease and Health Workshop: Developing Diagnostic Criteria co-convened by the Coral Disease and Health Consortium (CDHC), a working group organized under the auspices of the U.S. Coral Reef Task Force, and the International Registry for Coral Pathology (IRCP). The workshop was hosted by the U.S. Geological Survey, National Wildlife Health Center (NWHC) in Madison, Wisconsin and was focused on gross morphology and disease signs observed in the field. A resounding recommendation from the histopathologists participating in the workshop was the urgent need to develop diagnostic criteria that are suitable to move from gross observations to morphological diagnoses based on evaluation of microscopic anatomy. As a continuation of building the foundation and framework for coral disease diagnostics, the CDHC convened the Coral Disease and Health Workshop: Coral Histopathology II in Charleston, South Carolina, July 11-14, 2005. The workshop was hosted by the Department of Pathology and Laboratory Medicine at the Medical University of South Carolina, Charleston, SC which provided expertise, facilities and equipment in support of the workshop. All of the histological slides and related photographs used in the discussions were prepared and supplied by the IRCP. This workshop brought together 15 experts in veterinary and medical pathology and coral biology from national and international research institutes and government laboratories. The mission was to devise a standardized approach to examining microscopic anatomy and pathology of corals and a standardized nomenclature to facilitate accurate descriptions of the microscopic morphology of corals and enhance communication among specialists investigating causes of coral death. 2 The participants of this workshop deliberated for 3 days to refine the nomenclature for gross and microscopic anatomy of corals and systematically described microscopic changes associated with selected coral diseases. The findings and recommendations from the deliberations will be submitted to the research community for peer review. The standardized nomenclature and descriptions produced at this workshop will ultimately be made available to the scientific community through a variety of media including the World Wide Web. An exciting highlight of this meeting was provided by Professor Robert Ogilvie (MUSC Department of Cell Biology and Anatomy) when he introduced participants to a new digital technology that is revolutionizing histology and histopathology in the medical field. The Virtual Slide technology creates digital images of histological tissue sections by computer scanning actual slides in high definition and storing the images for retrieval and viewing. Virtual slides now allow any investigator with access to a computer and the web to view, search, annotate and comment on the same tissue sections in real time. Medical and veterinary slide libraries across the country are being converted into virtual slides to enhance biomedical education, research and diagnosis. The coral health and disease researchers at this workshop deem virtual slides as a significant way to increase capabilities in coral histology and a means for pathology consultations on coral disease cases on a global scale.

NOAA Technical Memorandum↗
USGS2005

El Niño and displays of spring-flowering annuals in the Mojave and Sonoran deserts

Although popular and scientific literature frequently assumes a strong connection between El Niño-Southern Oscillation (ENSO) and good displays of spring-flowering annuals in the southwestern United States, such assumptions are based on anecdotal, short-term evidence. The goals of this study were to identify good wildflower years as objectively as possible, to assess the correlation between El Niño and good displays of spring-flowering annuals, and to examine the influence of rainfall amounts on good wildflower years. The terms “good displays” and “good wildflower years” refer to times or places when populations of showy spring-flowering annuals (often called winter annuals) are abundant, robust, and diverse. In the deserts of southeastern California and southern Arizona, good wildflower years occurred about once every 5 to 7 years in the 20th century. The connection between good wildflower years and traditionally defined El Niño episodes was weak, but when El Niño was redefined in a phenologically meaningful way as any calendar year in which the average Southern Oscillation Index (SOI) between July and December was negative, 21 of 27 good wildflower years in the combined deserts were associated with El Niño. Good wildflower years were 3.6 times more likely after redefined El Niño years than after other years. Rain in the months before good wildflower years was at least 30% greater than the long-term average in the Mojave Desert and at least 50% greater in the Sonoran Desert. A diverse flora of spring-flowering annuals occurred in the region during the late Wisconsin and early Holocene, which was a period of wetter, milder winters and cooler summers. Perhaps some species of spring-flowering annuals persist today in the arid southwestern United States only because frequent El Niño conditions recreate the cool, moist conditions of the late Pleistocene.

Journal of the Torrey Botanical Society↗
USGS2014

Glacial geology of the Shingobee River headwaters area, north-central Minnesota

During middle and late Wisconsin time in the Shingobee River headwaters area, the Laurentide Wadena lobe, Hewitt and Itasca phases, produced terminal and ground moraine along with a variety of associated glacial features. The stratigraphic record is accessible and provides details of depositional mode as well as principal glacial events during the advance and retreat of middle and late Wisconsin ice tongues. Geomorphic features such as tunnel valleys, stream terraces, and postglacial stream cuts formed by erosional events persist to the present day. Middle Wisconsin Hewitt phase deposits are the oldest and include drumlins, ground moraine, boulder pavements, and outwash. Together, these deposits suggest a wet-based, periodically surging glacier in a subpolar thermal state. Regional permafrost and deposition from retreating ice are inferred between the end of the Hewitt phase and the advance of late Wisconsin Itasca phase ice. Itasca phase glaciation occurred as a contemporaneous pair of adjacent ice tongues whose contrasting moraine styles suggest independent flow modes. The western (Shingobee) portion of the Itasca moraine contains composite ridges, permafrost phenomena, hill-hole pairs, and debris flows. By contrast, eastern (Onigum) moraine deposits generally lack glaciotectonic features and consist almost exclusively of mud and debris flows. Near the end of the Itasca phase, large-scale hill-hole pairs developed in the Shingobee division, and debris flows from the Onigum division blocked the preexisting Shingobee tunnel valley to form glacial lake Willobee. Postglacial streams formed deep valleys as glacial lake Willobee catastrophically drained. Dates based on temperature trends in Greenland ice cores are proposed for prominent glacial events in the Shingobee area. This report proposes that Hewitt phase glaciation occurred between 27.2 and 23.6 kiloannum and Itasca phase glaciation between 22.8 and 14.7 kiloannum. Des Moines lobe (Younger Dryas) glaciation, which had only secondary effects on the Shingobee headwaters area, occurred between 13.5 and 11.6 kiloannum.

Minnesota↗
USGS2018

Evaluation of the effects of changes in the timing of water-level drawdowns on the export of phosphorus from Little St. Germain Lake, Wisconsin

Little St. Germain Lake is a 978-acre, multibasin lake in Vilas County, Wisconsin. In the interest of improving its water quality, the Little St. Germain Lake Protection and Rehabilitation District initiated a cooperative study with the U.S. Geological Survey to describe the current phosphorus input into and export from Little St. Germain Lake and evaluate how water releases at different times of the year could affect the amount of phosphorus being released from the lake, potentially affecting water quality in the lake. Approximately 780 pounds per year of phosphorus are exported out of the lake, which is about 80 percent of that contributed to the lake by Muskellunge Creek. By focusing the release of water to times when phosphorus concentrations near the outlet of the lake are highest, export of phosphorus from the lake could increase by about 60 to 80 pounds annually. This is equivalent to reducing phosphorus contributions from Muskellunge Creek by about 7 to 9 percent. Increasing phosphorus export from the lake should improve the long-term water-quality of the lake, especially in the southern basins of the lake.

Wisconsin↗
USGS2008

Flood of June 2008 in Southern Wisconsin

In June 2008, heavy rain caused severe flooding across southern Wisconsin. The floods were aggravated by saturated soils that persisted from unusually wet antecedent conditions from a combination of floods in August 2007, more than 100 inches of snow in winter 2007-08, and moist conditions in spring 2008. The flooding caused immediate evacuations and road closures and prolonged, extensive damages and losses associated with agriculture, businesses, housing, public health and human needs, and infrastructure and transportation. Record gage heights and streamflows occurred at 21 U.S. Geological Survey streamgages across southern Wisconsin from June 7 to June 21. Peak-gage-height data, peak-streamflow data, and flood probabilities are tabulated for 32 USGS streamgages in southern Wisconsin. Peak-gage-height and peak-streamflow data also are tabulated for three ungaged locations. Extensive flooding along the Baraboo River, Kickapoo River, Crawfish River, and Rock River caused particularly severe damages in nine communities and their surrounding areas: Reedsburg, Rock Springs, La Farge, Gays Mills, Milford, Jefferson, Fort Atkinson, Janesville, and Beloit. Flood-peak inundation maps and water-surface profiles were generated for the nine communities in a geographic information system by combining flood high-water marks with available 1-10-meter resolution digital-elevation-model data. The high-water marks used in the maps were a combination of those surveyed during the June flood by communities, counties, and Federal agencies and hundreds of additional marks surveyed in August by the USGS. The flood maps and profiles outline the extent and depth of flooding through the communities and are being used in ongoing (as of November 2008) flood response and recovery efforts by local, county, State, and Federal agencies.

Scientific Investigations Report↗
USGS2012

Evaluation of the effects of Middleton's stormwater-management activities on streamflow and water-quality characteristics of Pheasant Branch, Dane County, Wisconsin 1975-2008

Few long-term data sets are available for evaluating the effects of urban stormwater-management practices. Over 30 years of data are available for evaluating the effectiveness of such practices by the city of Middleton, Wis. Analysis of streamflow and water-quality data collected on Pheasant Branch, demonstrates the relation between the changes in the watershed to the structural and nonstructural best management practices put in place during 1975-2008. A comparison of the data from Pheasant Branch with streamflow and water-quality data (suspended sediment and total phosphorus) collected at other nearby streams was made to assist in the determination of the possible causes of the changes in Pheasant Branch. Based on 34 years of streamflow data collected at the Pheasant Branch at Middleton streamflow-gaging station, flood peak discharges increased 37 percent for the 2-year flood and 83 percent for the 100-year flood. A comparison of data for the same period from an adjacent rural stream, Black Earth at Black Earth had a 43 percent increase in the 2-year flood peak discharge and a 140-percent increase in the 100-year flood peak discharge. Because the flood peak discharges on Pheasant Branch have not increased as much as Black Earth Creek it appears that the stormwater management practices have been successful in mitigating the effects of urbanization. Generally urbanization results in increased flood peak discharges. The overall increase in flood peak discharges seen in both streams probably is the result of the substantial increase in precipitation during the study period. Average annual runoff in Pheasant Branch has also been increasing due to increasing average annual precipitation and urbanization. The stormwater-management practices in Middleton have been successful in decreasing the suspended-sediment and total phosphorus loads to Lake Mendota from the Pheasant Branch watershed. These loads decreased in spite of increased annual runoff and flood peaks, which are often expected to produce higher sediment and phosphorus loads. The biggest decreases in sediment and phosphorus loads occurred after 2001 when a large detention pond, the Confluence Pond, began operation. Since 2001, the annual suspended-sediment load has decreased from 2,650 tons per year to 1,450 tons per year for a 45-percent decrease. The annual total phosphorus load has decreased from 12,200 pounds per year to 6,300 pounds per year for a 48-percent decrease. A comparison of Pheasant Branch at Middleton with two other streams, Spring Harbor Storm Sewer and Yahara River at Windsor, that drain into Lake Mendota shows that suspended-sediment and total phosphorus load decreases were greatest at Pheasant Branch at Middleton. Prior to the construction of the Confluence Pond, annual suspended-sediment yield and total phosphorus yield from Pheasant Branch watershed was the largest of the three watersheds. After 2001, suspended-sediment yield was greatest at Spring Harbor Storm Sewer, and lowest at Yahara at Windsor; annual total phosphorus yield was greater at Yahara River at Windsor than that of Pheasant Branch. The stormwater-quality plan for Middleton shows that the city has met the present State of Wisconsin Administrative Code chap. NR216/NR151 requirements of reducing total suspended solids by 20 percent for the developed area in Middleton. In addition, the city already has met the 40-percent reduction in total suspended solids required by 2013. Snow and ice melt runoff from road surfaces and parking lots following winter storms can effect water quality because the runoff contains varying amounts of road salt. To evaluate the effect of road deicing on stream water quality in Pheasant Branch, specific conductance and chloride were monitored during two winter seasons. The maximum estimated concentration of chloride during the monitoring period was 931 milligrams per liter, which exceeded the U.S. Environmental Protection Agency acute criterion of 860 milligrams per liter. Chloride concentrations exceeded the U.S. Environmental Protection Agency chronic criterion of 230 milligrams per liter for at least 10 days during February and March 2007 and for 45 days during the 2007-8 winter seasons. The total sodium chloride load for the monitoring period was 1,720 tons and the largest sodium chloride load occurred in March and April of each year.

Wisconsin↗
USGS2017

Simulation of groundwater flow in the glacial aquifer system of northeastern Wisconsin with variable model complexity

The U.S. Geological Survey, National Water-Quality Assessment seeks to map estimated intrinsic susceptibility of the glacial aquifer system of the conterminous United States. Improved understanding of the hydrogeologic characteristics that explain spatial patterns of intrinsic susceptibility, commonly inferred from estimates of groundwater age distributions, is sought so that methods used for the estimation process are properly equipped. An important step beyond identifying relevant hydrogeologic datasets, such as glacial geology maps, is to evaluate how incorporation of these resources into process-based models using differing levels of detail could affect resulting simulations of groundwater age distributions and, thus, estimates of intrinsic susceptibility. This report describes the construction and calibration of three groundwater-flow models of northeastern Wisconsin that were developed with differing levels of complexity to provide a framework for subsequent evaluations of the effects of process-based model complexity on estimations of groundwater age distributions for withdrawal wells and streams. Preliminary assessments, which focused on the effects of model complexity on simulated water levels and base flows in the glacial aquifer system, illustrate that simulation of vertical gradients using multiple model layers improves simulated heads more in low-permeability units than in high-permeability units. Moreover, simulation of heterogeneous hydraulic conductivity fields in coarse-grained and some fine-grained glacial materials produced a larger improvement in simulated water levels in the glacial aquifer system compared with simulation of uniform hydraulic conductivity within zones. The relation between base flows and model complexity was less clear; however, the relation generally seemed to follow a similar pattern as water levels. Although increased model complexity resulted in improved calibrations, future application of the models using simulated particle tracking is anticipated to evaluate if these model design considerations are similarly important for understanding the primary modeling objective - to simulate reasonable groundwater age distributions.

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