USGS Science⌕ Search

Geology topics

Research about Wisconsin

Source-linked reports with geographic coverage including Wisconsin.

At least 649 records · Page 36Linked to original sources
USGS1993

Sources of pollutants in Wisconsin stormwater

Rainfall runoff samples were collected from streets, parking lots, roofs, driveways, and lawns. These five source areas are located in residential, commercial, and industrial land uses in Madison, Wisconsin. Solids, phosphorus, and heavy metals loads were determined for all the source areas using measured concentrations and runoff volumes estimated by the Source Load and Management Model. Source areas with relatively large contaminant loads were identified as critical source areas for each land use. Streets are critical source areas for most contaminants in all the land uses. Parking lots are critical in the commercial and industrial land uses. Lawns and driveways contribute large phosphorus loads in the residential land use. Roofs produce significant zinc loads in the commercial and industrial land uses. Identification of critical source areas could reduce the amount of area needing best-management practices in two areas of Madison, Wisconsin. Targeting best-management practices to 14% of the residential area and 40% of the industrial area could significantly reduce contaminant loads by up to 75%.

Wisconsin↗
USGS1993

Hydrologic and water-quality data for the East River Basin in northeastern Wisconsin

Hydrologic and precipitation data and water-quality samples were collected by the U.S. Geological Survey from rivers in the East River basin in northeastern Wisconsin during 1985-86. The Fox Valley Water Quality Planning Agency suspected that agricultural and urban nonpoint-source discharges were contributing significantly to the degradation of water quality in the basin. Two continuous record streamflow and waterquality gaging stations were established: one on the East River at Monroe Street in Green Bay and the other on Bower Creek at Sunnyview Road near De Pere. Streamflow for the 1986 water year was greater than twice the long-term (1967-86) average and precipitation was 33 percent greater than the long-term (1951-80) average. Average daily streamflow at the East River during the 1986 water year was 185 cubic feet per second. Average daily streamflow at Bower Creek was 6 cubic feet per second. Suspended-sediment yields were greatest in Bower Creek 264 tons per square mile per year; yields were 125 tons per square mile per year at the East River site. Total-phosphorus yields at the Bower Creek gage were 2,680 pounds per square mile per year yields were 1,130 pounds per square mile per year at the East River site. The measured yields of suspended sediment and total phosphorus from the East River site, during the 1986 water year, were significantly larger than the estimated average yields for the Fox River at Wrightstown. During a year of normal streamflow, the East River would probably contribute a maximum of 10 percent of the total suspended sediment and 9 percent of the total-phosphorus load transported to the mouth of the Fox River. Dissolved-oxygen concentrations tended to decrease upstream from the mouth of the East River. The daily mean dissolved-oxygen concentration was often less than 5 milligrams per liter at all three of the East River monitoring locations. Minimum dissolved-oxygen concentrations of 1 to 2 milligrams per liter were recorded at all sites. The acceptable fecal coliform level for recreational water quality of 200 counts per 100 milliliters was exceeded at the three East River sites and Bower Creek in more than half of the samples. More samples collected at the downstream sites on the East River at Monroe Street in Green Bay and at the Allouez Avenue bridge at Allouez contained fecal-coliform/fecal-streptococcus ratios that exceeded 4.0, indicating that the bacteria was of human origin rather than of animal. Mean concentrations for 5-day biochemical oxygen demand, total-phosphorus concentration, fecal-coliform counts, and fecal-streptococcus counts were higher at Bower Creek than any of the other sites monitored during 1985-86. Mean chlorophyll a concentrations were highest at the East River sites at Monroe Street in Green Bay and at Allouez Avenue bridge at Allouez.

Wisconsin↗
USGS1993

Water Use in Wisconsin, 1990

INTRODUCTION As part of the National Water-Use Information Program, the U.S. Geological Survey (USGS) stores water-use data in standardized format for different categories of water use. The data base (Site Specific Water Use Data System) is updated annually or as more current water-use information becomes available. Information about amounts of water withdrawn, sources of water, how the water was used, and how much water was returned is available to those involved in establishing water-resource policy and to those managing water resources. In 1978, the USGS entered into a cooperative program with the Wisconsin Department of Natural Resources (WDNR) to inventory water use in Wisconsin. Since that time, two reports that summarize water use have been published (Lawrence and Ellefson, 1982; Ellefson and others, 1987). Ellefson and others (1987) present 1985 water-use data in a map and graph format. Because water use changes with time, an update report is periodically required. This report presents 1990 data in the same format as that of the 1987 report.

Wisconsin↗
USGS1993

Water-resources investigations in Wisconsin, 1993

PROBLEM: Surface-water information is needed for surveillance, planning, design, hazard warning, operation, and management in water-related fields such as water supply, hydroelectric power, flood control, irrigation, bridge and culvert design, wildlife management, pollution abatement, flood-plain management, and water-resources development. An appropriate data base is necessary to provide this information. OBJECTIVE: The objectives of this study are to provide continuous discharge records for selected rivers at specific sites to supply the needs for: regulation, analytical studies, definition of statistical properties, trends analysis, determination of the occurrence, and distribution of water in streams for planning. The project is also designed to determine lake levels and to provide discharge for floods, low-flow conditions, and for water-quality investigations. Requests for streamflow data and information relating to streamflow in Wisconsin are answered. Basic data are published annually in "Water Resources Data Wisconsin."

Wisconsin↗
USGS1993

Concentrations and loads of polychlorinated biphenyls in major tributaries entering Green Bay, Lake Michigan, 1989-90

The U.S. Geological Survey collected water samples from the five major tributaries to Green Bay, Lake Michigan, to determine the load of total polychlorinated biphenyls (RGB's) entering the bay. These samples were collected from January 1989 through early May 1990 from the Escanaba, Menominee, Peshtigo, Oconto, and Fox Rivers. Sampling sites were located near the mouth of each river and also just upstream of De Pere dam on the Fox River. Water samples were collected for analysis of total, dissolved, and particulate concentrations of PCB's at the nanogram-per-liter level. Loads of PCB's entering Green Bay were computed using a total-integration method. The methods used to collect water samples and compute the loads of total PCB's entering the bay are described in this report. Graphs showing total PCB's concentrations and loads are presented for each site, along with the corresponding data tables. These data indicate that the amount of total PCB's entering the bay from the Fox River is greater than from all other major tributaries combined.

Wisconsin↗
USGS1993

Water quality of an urban wet detention pond in Madison, Wisconsin, 1987-88

A 5,670-sq m wet detention pond was monitored by the U.S. Geological Survey to determine its effect on the water quality of urban runoff. The pond has a drainage area of 0.96-sq km, composed primarily of single-family residential land use. Event-mean concentrations (EMC) were determined from samples collected for sediment, nutrients, and selected metals at the pond's inflow and outflow sites. EMC samples were collected for 64 runoff events during the study period from February 1987 to April 1988. Storm precipitation ranged from 1 to 51 mm during these events. Inflow and outflow EMC and constituent loads were compared to determine the trap efficiency of the pond. Trap efficiency varied considerably among water-quality constituents. In general, the detention pond decreased the EMC of sampled constituents at the outlet compared to the inlet. The median decrease in EMC for suspended solids was 88 percent, 60 percent for total chemical oxygen demand (COD), 43 percent for total phosphorus, 38 percent for total Kjeldahl nitrogen, 65 percent for total nitrite plus nitrate, and 71 percent for total lead. A notable exception to the general decrease in EMC is for chloride. The EMC for chloride was generally higher in outflow from the pond than in the inflow. This is attributed to an unmonitored influx of chloride to the pond during the winter that subsequently was flushed out during monitored runoff events. The total study-period loads of most constituents were less leaving the pond than the loads entering it. This decrease is attributed to the constituents transported on suspended sediment being deposited in the pond. The decrease in total load of suspended solids was 88 percent, 62 percent for total COD, 58 percent for total phosphorus, 46 percent for total Kjeldahl nitrogen, 62 percent for total nitrite plus nitrate, 97 percent for total copper, and 93 percent for total lead. (USGS)

Wisconsin↗
USGS1993

Evaluation of nonpoint-source contamination, Wisconsin: Selected data for 1992 water year

This report presents the annual results of the U.S. Geological Survey's (USGS) watershed-management evaluation monitoring program in Wisconsin. The overall objective of each individual project in the program is to determine if the water chemistry in the receiving stream has changed as a result of the implementation of land-management practices in the watershed. This is accomplished through monitoring of water chemistry and ancillary variables before best-management practices (BMP's) are installed ('pre-BMP'), during installation ('transitional'), and after ('post-BMP') watershed- management plans have been completely implemented. Fecal-coliform (FC) counts ranged between 10 and 310,00/100 mL. A large range of values occurred within duplicate and triplicate samples as well as over time. The median percentage difference between duplicate and triplicate samples was 17 percent although 4 out of the total 60 duplicate and triplicate samples had differences greater than 100 percent. A decrease in FC counts generally occurred over the duration of the 4-day analyses. Linear regression models of the log-concentration values (dependent variable) with respect to time (independent variable) were calculated for all samples. Negative slopes were found for 14 of the 15 samples. Slopes varied from +0.5 to -38.4 percent gain/loss/day, with a median slope of -8.5 percent/day. A t-test was applied to the data to examine whether or not significant differences in FC counts exist with respect to holding times. Because the T-test only compares two treatments, the test was conducted 3 times (0 versus 24-hr holding time, 0 versus 48-hr holding time, and 0 versus 72-hr holding time). Setting the level of significance at p less than 0.05 and assuming equal variances, 27 percent (all from Bower and Otter Creeks) of the samples demonstrated a significant difference in colony count over the first 24 hr, 40 percent over 48 hr, and 47 percent over 72 hr. All samples that exhibited a significant change in colony count were because of a decrease in colony count of the sample.

Wisconsin↗
USGS1993

Hydrology and water quality of Powers Lake, southeastern Wisconsin

This report describes the hydrology and water quality of Powers Lake, a recreational lake in a densely populated area of southeastern Wisconsin, from October 16, 1986 - October 15, 1987. The hydrologic budget for the study period showed that direct precipitation on the lake and ground water were dominant sources of water entering the lake (37 and 36 percent, respectively) and that streamflow dominated the outflow. Surface runoff contributed 27 percent of the inflow-23 percent from Powers Lake inlet and 4 percent from shoreline drainage. Streamflow through Powers Lake outlet accounted for 62 percent of the outflow and evaporation accounted for 38 percent. Based on the streamflow from Powers Lake outlet, the lake's hydraulic residence time was 3.8 years. During the study period, precipitation was 27.16 inches or 4.08 inches below long-term (1951-80) average. The data were adjusted or normalized to represent an average year of precipitation and runoff to help evaluate the water quality of the lake for an average year. For an average year, precipitation dominated inflow (42 percent), followed by ground water (32 percent), Powers Lake inlet (21 percent), and shoreline drainage (5 percent). Streamflow through Powers Lake outlet accounted for 61 percent of an average year's outflow budget and the remaining 39 percent was evaporation. Based on an average year's streamflow from Powers Lake outlet, the lake's hydraulic residence time was 4.2 years. Phosphorus budgets were prepared for the study period and for an estimated normal year. The phosphorus budget for the study period showed that, of the total inputs (516 pounds), surface runoff contributed the largest amount; shoreline drainage contributed 44 percent, and Powers Lake inlet contributed 36 percent. Direct precipitation contributed 11 percent; ground water, 2 percent; and septic systems, 7 percent. Of the total outputs, 83 pounds (16 percent) was lost from the lake via the outlet; 433 pounds (84 percent) was lost to the sediments as the phosphorus that was attached to particles settled to the lake bottom. An estimated phosphorus budget for a normal year showed that of the total inputs (744 pounds), surface runoff contributed the largest amount; Powers Lake inlet contributed 45 percent and shoreline drainage contributed 35 percent. Precipitation contributed 9 percent; ground water, 1 percent; and septic systems, 10 percent. The health of the lake was evaluated using Carlson's Trophic State Index and Vollenweider's model. Carlson's Trophic State Index showed that Powers Lake was moderately enriched and in the mesotrophic range. Comparison of guidelines from Vollenweider's model showed that the total phosphorus input for the study period and for an estimated average year would not cause eutrophic conditions.

Wisconsin↗
USGS1993

Hydrology, water quality, trophic status, and aquatic plants of Fowler Lake, Wisconsin

The U.S. Geological Survey, in cooperation with the Fowler Lake Management District, completed a hydrologic and water-quality study of Fowler Lake in southeastern Wisconsin during calendar year 1984. Data on temperature, pH, specific conductance, and concentrations of dissolved oxygen, total phosphorus, dissolved orthophosphate phosphorus, and various nitrogen species were collected from January through November 1984. The water-quality data indicate that Fowler Lake can be classified as a mildly fertile lake with excellent water clarity as indicated by Secchi depth readings generally greater than 12 feet. Although phosphorus concentrations are generally less than 0.01 milligram per liter, the lake does produce dense stands of macrophytes during the open-water period. The lake is thermally stratified during the summer months, resulting in oxygen depletion in the deepest parts of the lake. The average hydraulic residence time for Fowler Lake during 1984 was 6.9 days, which is substantially less than the 305 days for upstream Okauchee Lake or the 145 days for downstream Lac La Belle. Precipitation during 1984 was about 27 percent higher than normal and streamflows in the area were about 55 percent higher than normal. The Oconomowoc River contributed 98 percent of the inflow and 88 percent of the phosphorus load to Fowler Lake. The low annual phosphorus input (28 pounds per square mile) to the lake from the Oconomowoc River shows the benefit of upstream lakes on the Oconomowoc River. Fourteen percent of the phosphorus input load to Fowler Lake is deposited in the lake sediments and the rest is transported through the lake by surface-water flow to downstream Lac La Belle. Dense growths of macrophytes in the lake change in composition seasonally; chara sp. (muskgrass) and Myriophyllum sp. (milfoil) are abundant in June and Najas marina and Vallesneria Americana (wild celery) are abundant in August.

Wisconsin↗
USGS1993

Hydrology and water quality of Wind Lake in southeastern Wisconsin

The hydrology and water quality of Wind Lake-a recreational lake in a densely populated area of southeastern Wisconsin was studied from October 1, 1987 through September 30,1989. A drought in 1988 affected the hydrologic budget of Wind Lake in water years 1988-89. Precipitation was 5.9 inches less than normal in water year 1988 but was 2.3 inches greater than normal in water year 1989. Streamflows were near normal in water year 1988 and 25 percent less than normal in water year 1989 as indicated by data from a nearby streamflow-gaging station. Surface runoff was the dominant source of water to the lake in water year 1988 and 75 percent of the inflow was from Big Muskego Lake. The water level in Big Muskego Lake was 1.1 feet below the dam crest at the start of the 1989 water year because of the 1988 drought. About 2,510 acre-feet of water had to fill Big Muskego Lake before water could discharge to Wind Lake. In water year 1989, surface runoff was still the dominant source of water to the lake, but Big Muskego Lake only contributed 52 percent of the water inflow. Streamflow dominated the outflow budget for both years. In water year 1988, 88 percent of the outflow budget left by way of Wind Lake outlet and 12 percent evaporated from the lake surface. In water year 1989, 81 percent of the outflow budget left by way of Wind Lake outlet and 19 percent evaporated from the lake surface. On the basis of outflow from Wind Lake for water year 1988, the hydraulic residence time was 0.46 year; in water year 1989 it was 1.05 years. The total phosphorus input to Wind Lake from external sources was the same for both years, 3,160 pounds. The largest percentage of the phosphorus load came from Big Muskego Lake-- 70 percent in water year 1988 and 65 percent in water year 1989. Analysis of data by use of Vollenweider's model indicates that the phosphorus loadings for each year would cause eutrophic conditions. Data from a nearby gaging station indicate that phosphorus loading to Wind Lake was less than normal. Phosphorus retention in the lake is small and averages 14 percent of the incoming load for both years. Oxygen depletion occurs in the bottom waters during winter and summer months. A maximum anoxic zone was reached on July 18, 1988, when depths greater than 15 feet (about 21 percent of the lake bottom area) were anoxic. Total phosphorus concentrations at the lake surface for both years ranged from 11 to 78 micrograms per liter. Mean total phosphorus concentrations in June, July, and August that had averaged 49 micrograms per liter in 1985 through 1987 declined to 20 micrograms per liter in water year 1988 and 22 micrograms per liter in water year 1989. This reduction was related to the drought and reduced phosphorus loadings. Phosphorus concentrations 1.5 feet above the lake bottom increase during summer anoxic periods. The phosphorus concentration increased at a rate of 5.2 and 4.8 micrograms per liter per day for total and dissolved orthophosphate phosphorus. A maximum concentration of 760 micrograms per liter of total phosphorus and 650 micrograms per liter of dissolved orthophosphate phosphorus occurred on September 21, 1988, just before autumn turnover. Internal loading of phosphorus for the period October 15, 1987 through October 14, 1988, was estimated to be 2,890 pounds. This represents 48 percent of the combined internal and external total-phosphorus input of 5,960 pounds. Algal populations in water year 1988 ranged from 28,200 to 1,610,000 cells per milliliter. A total of 143 species were identified. Blue-green algae dominated the algal population and ranged from 56 percent (February 16, 1988) to 99 percent (five other sampling dates). Aphanocapsa delicatissima caused the largest algal bloom, which reached a maximum concentration of 934,000 cells per milliliter (September 7, 1988). Zooplankton populations in water year 1988 ranged from 52.5 to 686 organisms per liter. Eighteen species were identified. The cladoceran, Daphnia, dominated 12 of the 18 samples.

Wisconsin↗
USGS1993

Water and phosphorus budgets and trophic state, Balsam Lake, northwestern Wisconsin, 1987-1989

Water and total-phosphorus budgets were determined for Balsam Lake in northwestern Wisconsin. All significant components of the lake's water budget were determined independently. The lake's trophic state was evaluated in relation to total-phosphorus loading from December 1, 1987 through November 30, 1989. The information obtained in the study can be used by local and State agencies to develop and assess lake- and watershed-management alternatives for maintaining or improving the water quality of the lake. The three-basin, 1,900-acre drainage lake receives flow from two main tributary streams, Harder and Rice Creeks. Precipitation, ground-water levels, and streamflow were below normal during the study period and the year preceding the study. Precipitation was 6.09 inches below normal the first year of the study and 8.71 inches the second year. Precipitation, the dominant water-budget inflow component, was followed in decreasing order by inflows from Rice Creek, ground water, Harder Creek, and near-lake drainage. Total inflows in the first and second years of the study were 11,040 and 11,650 acre-feet, respectively. Surface inflow was 23 percent greater in the second year of the study than in the first year. The largest outflow from Balsam Lake was outflow to Balsam Branch, and the second largest outflow was evaporation. These outflows accounted for 98 percent of outflow from the lake. Recharge to ground water accounted for 2 percent. Total-phosphorus input to the lake was 692 and 1,144 pounds in the first and second years of the study. Rice Creek and near-lake drainage accounted for 80 percent of phosphorus entering the lake. Outflow to Balsam Branch removed 30 percent of the phosphorus that entered the lake. The main basin of the lake was mesotrophic, whereas the loading rates determined for the study period would have expected to result in oligotrophic conditions. Internal loading and below-normal external loading during the study are the likely explanation for this discrepancy. The northwest basin of the lake (locally called "Little Balsam Lake") received 66 percent of all external phosphorus that entered Balsam Lake. The trophic state of Little Balsam Lake ranged from upper mesotrophic to lower eutrophic. Phosphorus that entered Little Balsam Lake during the study period would have been expected to result in eutrophic conditions.

Wisconsin↗
USGS1993

Hydrology and water quality of the Forest County Potawatomi Indian Reservation, Wisconsin

This report presents data from a study by the U.S. Geological Survey, in cooperation with the Forest County Potawatomi Community of Wisconsin, to document the hydrology and water quality of the Potawatomi Indian Reservation in southern Forest County. Data were collected from October 1981 through September 1987. Glacial sand and gravel forms the primary aquifer on the reservation. This aquifer is unconfined, and its saturated thickness ranges from approximately 200 feet to zero feet in areas where the bedrock crops out. Horizontal hydraulic conductivity of the glacial deposits is estimated to range from 0.4 to 48 feet per day. Three watersheds encompass the Reservation: The Wolf, the North Branch Oconto, and the Peshtigo. Estimates of base-flow discharge that will occur on the average once every 2 years for a 7- day period for Reservation streams range from 7.5 ft3/s (cubic feet per second) for North Branch Oconto at Wabeno to 32 ft3/s for the Rat River near Wabeno. Ground water in the study area is a calcium magnesium bicarbonate type and is suitable for most uses. The ground water sampled during the study was slightly alkaline and moderately hard to very hard; median hardness was 135 mg/L (milligrams per liter) as calcium carbonate. Alkalinity of ground water ranged from 79 to 318 mg/L; median alkalinity was 123 mg/L as calcium carbonate. With the exception of nitrate in water from one well sampled, constituent concentrations were less than the U.S. Environmental Protection Agency's Maximum Contaminant Levels (MCL's) for drinking water. Nitrate plus nitrite concentration was 15 mg/L as N, or 50 percent greater than the MCL, in one well located one-half mile northeast of Lake Lucerne. Secondary Maximum Contaminant Levels (SMCL's) for iron were exceeded in water from two wells. In one of these two well waters, the manganese concentration equaled the SMCL. Streams on the Reservation also contain a calcium magnesium bicarbonate type water. The stream waters are slightly alkaline and are considered soft to moderately hard; median hardness in stream samples was 56 mg/L as calcium carbonate. The alkalinity in stream samples ranged from 46 to 59 mg/L as calcium carbonate; the median value was 51 mg/L. Stream water is intermediate between hard, alkaline ground water and soft, acidic precipitation and surface runoff. Low but detectable concentrations of chromium, copper, iron, magnesium, mercury, and zinc were detected in most bottom-material samples. Water quality of three lakes on the Reservation is variable and depends on the degree of connection with the ground-water system. In general, Bug Lake and Devils Lake are in poor hydraulic connection with the ground-water system, and their waters contain low concentrations of dissolved solids and alkalinity and low pH. King Lake is in good hydraulic connection with the ground-water system, and its waters contain higher concentrations of dissolved solids and alkalinity and higher pH than Bug and Devils Lakes.

Wisconsin↗
USGS1993

Simulation of the effects of hypothetical residential development on water levels in Graber Pond, Middleton, Wisconsin

An investigation of the effects of hypothetical residential development in the Graber Pond watershed was done by the U.S. Geological Survey in cooperation with the city of Middleton. The investigation entailed evaluation of the existing (1989) water budget and water-level conditions for the pond and the water-level conditions expected to result from the hypothetical development that may occur by the year 2000. A water-budget model was calibrated to closely match water levels observed from July 18-August 31, 1989. Water input to the pond during this period was computed to be about 2.58 feet. Of this, about 25 percent (0.65 foot) was from direct rainfall on the pond surface, about 19 percent (0.50 foot) was from storm runoff, and about 55 percent (1.43 feet) was discharge from a nearby manufacturing plant. Simulation of the hypothetical development conditions in the watershed predicts that the average late-summer pond level may rise about 0.7 foot.

Wisconsin↗
USGS1993

Hydrogeology of glacial deposits in a preglacial bedrock valley, Waukesha County, Wisconsin

This report describes the areal extent, thickness, and hydraulic properties of glacial deposits in a preglacial bedrock valley south of the city of Waukesha in southeastern Wisconsin. In the 40- square-mile study area, the preglacial bedrock valley underlies an area across which the Fox River flows. A previous regional study of the area indicated that extensive glacial sand and gravel deposits may exist in the preglacial bedrock valley. New test-hole, well-construction, and seismic data collected from 1986 through 1991 showed that the preglacial bedrock valley immediately south of the city of Waukesha is narrower and shallower than previously thought. However, these data indicate that thicknesses of saturated glacial deposits in excess of 250 feet exist in a 1- to 2-mile-wide part of the valley in the southern part of the study area. Test-hole logs indicate that clean sand and gravel deposits are present in a shallow part of the preglacial bedrock valley. Fifty to sixty feet of silty and clayey sand and gravel deposits appear to underlie varying thicknesses of relatively impermeable clay till in the center of the study area. Ground water flows from upland areas on the eastern and western sides of the Fox River and discharges to the Fox River and wetlands adjacent to the river. Results of a 6.5-hour aquifer test indicate that the silty sand and gravel deposits have an average transmissivity of about 140 feet squared per day and an average storage coefficient of about 1.2x10"3 at one location. The horizontal hydraulic conductivity of these deposits averages about 4 feet per day. Analysis of drawdown indicates that these deposits are part of a leaky confined-aquifer system and that some water is derived from storage in an overlying clay layer. The transmissivity value determined from this aquifer test and a lack of clean sand and gravel encountered in other test holes indicate that glacial deposits at these sites may not yield enough water for a large municipal water supply. Sand and gravel deposits, capable of development as a municipal supply, may be present in the southern part of the study area. However, additional test holes are needed to determine whether adequate sand and gravel deposits underlie this area.

Wisconsin↗
USGS1993

Surface-water hydrology and quality, and macroinvertebrate and smallmouth bass populations in four stream basins in southwestern Wisconsin, 1987-90

Data on streamflow, water quality, and macroinvertebrate and smallmouth bass (microptercus dolomieni) populations were collected from July 1987 through September 1990, in four streams in southwestern Wisconsin to determine the effect of surface-water hydrology and quality on populations of macroinvertebrates and smallmouth bass. The study was a joint project of the U.S. Geological Survey and the Wisconsin Department of Natural Resources. Drought conditions greatly affected streamflows in southwestern Wisconsin throughout much of the period of study. Precipitation in all four basins in 1988 and 1989 was 9.91 to12.41 inches less than 1951-80 normal precipitation of 32.88 inches. The lowest annual mean discharge was recorded in water year 1988 at all of the streamflow- gaging stations except at Rattlesnake Creek, where annual mean discharge was lowest in water year 1990. Overland-flow runoff during the reproductive period of smallmouth bass (mid-May to mid-July) was 0.02 inch in 1988 at the Sinsinawa River and Rattlesnake Creek. Overland-flow runoff in the Little Platte River and the Livingston Branch of the Pecatonica River also was low in 1988 (0.03 inch and 0.04 inch, respectively) during the reproductive period of smallmouth bass. The trend of low overland-flow runoff continued in 1989; in water year 1990, however, overland-flow runoff during the reproductive period of smallmouth bass was 1.38 inches at Livingston Branch of the Pecatonica River and 0.22 inch at Rattlesnake Creek. Turbidity ranged from 1.5 nephelometric turbidity units at Rattlesnake Creek to 3,700 nephelometric turbidity units at the Sinsinawa River. Suspended-solid concentrations ranged from 2 milligrams per liter at Rattlesnake Creek to a maximum 24,300 milligrams per liter at the Livingston Branch of the Pecatonica River. The high turbidities and suspended-solid concentrations, which occurred during storms, did not last for long periods of time and are not thought to have been harmful to the biota of the rivers. Un-ionized ammonia concentrations exceeded the State of Wisconsin, Department of Natural Resources' standard of 0.04 milligram per liter for warmwater streams at all four of the streams. The maximum concentration of un-ionized ammonia measured was 0.10 milligram per liter at Rattlesnake Creek and there was no discernible effects on smallmouth bass or macroinvertebrates. Dissolved-oxygen concentrations at all four study streams occasionally decreased to below or near the concentration of 1 milligram per liter considered necessary to sustain life of smallmouth bass. Two fish kills were documented as the result of low dissolved-oxygen concentrations. All of these episodes of low dissolved-oxygen concentrations occurred during or just after rainstorms and subsequent increasing streamflows. Samples of water-sediment mixture and bottom material were analyzed for pesticides commonly used in the basins. Samples from all of the stations had concentrations of herbicides that exceeded the analytical reporting limit. Water-sediment samples at the Sinsinawa River had the highest herbicide concentration. The concentration of metolachlor was the highest of the herbicides-- 110 micrograms per liter; concentrations of atrazine and cyanazine were next highest at 97 and 84 micrograms per liter, respectively. All of the water-sediment mixture samples had insecticide concentrations below the analytical reporting limit, with the exception of carbofuran. One water-sediment mixture sample collected at the Little Platte River had a carbofuran concentration of 0.44 microgram per liter. No pesticides were detected in the bottom-material samples collected at the four study streams. Richness of macroinvertebrate taxa did not differ substantially among the four streams during the study, but the abundances of several taxa differed significantly among streams. Livingston Branch of the Pecatonica River had comparatively few midges but many caddisflies, whereas Rattlesnake Creek had many non-insect taxa and relatively few caddisflies. The Little Platte River had consistently high numbers of caddisflies, mayflies, and riffle beetles. Macroinvertebrate-community composition, as measured by Bray-Curtis dissimilarity coefficients, varied considerably over time within and among the streams. The macroinvertebrate community composition of the Little Platte River changed very little during the winter of 1987-88 as compared to the other streams, but the community composition of the Livingston Branch of the Pecatonica River changed substantially. The communities of Rattlesnake Creek and Livingston Branch of the Pecatonica River became more similar to the community of the Little Platte River from fall 1987 through fall 1988, whereas the community in the Sinsinawa River remained distinct. Water quality, as estimated by biotic-index values, generally was better in the Little Platte River than in the other streams from fall 1987 through fall 1988. However, water quality appeared to have deteriorated (biotic-index values increased) in the Little Platte River during the winter of 1988-89. Water quality in the Livingston Branch of the Pecatonica River also deteriorated during the same period. The drought of 1988-89 and accompanying decrease in frequency of storms contributed to an uncharacteristically stable environment for macroinvertebrate development in most streams. Total taxa richness increased in three of the four streams. Total taxa richness did not increase in the Little Platte River, possibly because of moderate flooding that occurred prior to the spring 1989 sampling period or, more likely, because of changes in dissolved-oxygen concentrations. Although dissolved-oxygen concentrations were fairly similar in all streams, dissolved-oxygen concentrations were lower in 1989 in the Little Platte River than in other streams. The observed increase in biotic-index values in the Little Platte River during the spring of 1989 supports a decline in water quality. Smallmouth bass reproduction was related to precipitation and streamflow during the critical mid-May to mid-July reproductive period. Reproductive success was good (38-297 Age 0 smallmouth bass per acre) in 1988 and 1989 and poor (0-3 Age 0 smallmouth bass per acre) in 1987 and 1990. This pattern corresponded with total precipitation of less than 7 inches in May and June in 1988 and 1989 and greater than 7 inches in 1989 and 1990. In years when runoff exceeded 0.10 inch, only three or fewer Age 0 (smallmouth bass less than 1 year old) smallmouth bass per acre were caught in late summer to fall sampling surveys. In contrast, when overland runoff was less than 0.10 inch, 32 to 297 Age 0 smallmouth bass per acre were found in late summer or fall. The numbers of Age 0 smallmouth bass per acre were significantly different from each other at the 1 -percent probability level (p=0.0001). Smallmouth bass reproductive success indicated that smallmouth bass in these streams were extremely vulnerable to the amount of runoff during the early stage of their life. Low concentrations of dissolved oxygen constituted the most detrimental water-quality problem affecting smallmouth bass populations. Dissolved-oxygen concentrations were occasionally less than 3 milligrams per liter, a dissolved-oxygen concentration that may be detrimental to early-life stages of smallmouth bass in the streams; however, smallmouth bass were apparently able to withstand these low dissolved-oxygen concentrations and seem to have survived in some situations when dissolved-oxygen concentration decreased to1 milligram per liter.

Wisconsin↗
USGS1993

Hydrology of Little Rock Lake in Vilas County, north-central Wisconsin

Water budgets were developed for Little Rock Lake for October 1983 through September 1990 as part of a study to evaluate the chemical and biological effects of artificially acidifying one basin of the two-basin lake. The 17.9-hectare seepage lake is situated in 60- to 90-meter-thick, predominantly sand and gravel glacial deposits of Vilas County, north-central Wisconsin. Annual precipitation during the study varied from 647 to 926 mm (millimeters). Average annual precipitation during 1951-80, based on nearby National Weather Service stations, was 825 mm. Annual evaporation from the lake surface ranged from 495 to 648 mm. Total lake-stage fluctuation was 930 mm during the study. Lake volume at the maximum stage was 31 percent greater than at the minimum lake stage. Inflow to the lake was dominated by precipitation, which was about 99 percent of total inflow. Ground-water inflow to the lake was transient, occurring only intermittently during October 1983 through September 1986, and amounted to only about 1 percent of total inflow. No ground water flowed into the lake from October 1986 through September 1990. Evaporation accounted for about two-thirds of total outflow from the lake, and lake water discharging to the underlying aquifer accounted for the remainder. The average hydraulic residence times for the 7-year study period were 3.9, 3.3, and 4 years for the entire lake, the south basin, and the north basin, respectively; corresponding chemical residence times were 10.9, 9.3, and 10 years.

Wisconsin↗
USGS1992

Impacts of variation in planktivorous fish on abundance of daphnids: A simulation model of the Lake Mendota food web: Chapter 20

Previous chapters in this volume have outlined the goals of the Lake Mendota food web manipulation study (Rudstam et al., Ch. 12) and have reported on variations in phytoplankton and zooplankton abundances during the past 15 years (Lathrop and Carpenter, Ch. 7 and 8). Because of the long time scales inherent in such a lake management manipulation, it became imperative to attempt to predict how the lake would respond to changes in planktivorous fish abundance over time scales of several decades. We know from the past 15 years of study (Lathrop and Carpenter, Ch. 7 and 8; Magnuson and Lathrop, Ch. 11) that substantial variation of planktivorous fish, zooplankton, and phytoplankton abundances can occur the lake. Given the current stocking of piscivores, we have the potential to substantially modify the abundance of planktivorous fish and possibly shift the assemblages of phytoplankton and zooplankton beyond the ranges of those which occurred previously. In this chapter we describe the construction and use of a simulation model designed to examine how variation in plantivore abundance might impact zooplankton biomass and species composition.

Wisconsin↗