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Research about Waukesha County, Wisconsin

Source-linked reports with geographic coverage including Waukesha County, Wisconsin.

9 recordsLinked to original sources
USGS2011

Application of the Local Grid Refinement package to an inset model simulating the interaction of lakes, wells, and shallow groundwater, northwestern Waukesha County, Wisconsin

Groundwater use from shallow, high-capacity wells is expected to increase across southeastern Wisconsin in the next decade (2010-2020), owing to residential and business growth and the need for shallow water to be blended with deeper water of lesser quality, containing, for example, excessive levels of radium. However, this increased pumping has the potential to affect surface-water features. A previously developed regional groundwater-flow model for southeastern Wisconsin was used as the starting point for a new model to characterize the hydrology of part of northwestern Waukesha County, with a particular focus on the relation between the shallow aquifer and several area lakes. An inset MODFLOW model was embedded in an updated version of the original regional model. Modifications made within the inset model domain include finer grid resolution; representation of Beaver, Pine, and North Lakes by use of the LAK3 package in MODFLOW; and representation of selected stream reaches with the SFR package. Additionally, the inset model is actively linked to the regional model by use of the recently released Local Grid Refinement package for MODFLOW-2005, which allows changes at the regional scale to propagate to the local scale and vice versa. The calibrated inset model was used to simulate the hydrologic system in the Chenequa area under various weather and pumping conditions. The simulated model results for base conditions show that groundwater is the largest inflow component for Beaver Lake (equal to 59 percent of total inflow). For Pine and North Lakes, it is still an important component (equal, respectively, to 16 and 5 percent of total inflow), but for both lakes it is less than the contribution from precipitation and surface water. Severe drought conditions (simulated in a rough way by reducing both precipitation and recharge rates for 5 years to two-thirds of base values) cause correspondingly severe reductions in lake stage and flows. The addition of a test well south of Chenequa at a pumping rate of 47 gal/min from a horizon approximately 200 feet below land surface has little effect on lake stages or flows even after 5 years of pumping. In these scenarios, the stage and the surface-water outflow from Pine Lake are simulated to decrease by only 0.03 feet and 3 percent, respectively, relative to base conditions. Likely explanations for these limited effects are the modest pumping rate simulated, the depth of the test well, and the large transmissivity of the unconsolidated aquifer, which allows the well to draw water from upstream along the bedrock valley and to capture inflow from the Bark River. However, if the pumping rate of the test well is assumed to increase to 200 gal/min, the decrease in simulated Pine Lake outflow is appreciably larger, dropping by 14 percent relative to base-flow conditions.

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USGS2000

Simulation of the shallow hydrologic system in the vicinity of Middle Genesee Lake, Wisconsin, using analytic elements and parameter estimation

Middle Genesee Lake is a ground-water flow-through lake located in a developing area in southeastern Wisconsin. Because the lake is in good connection with the shallow ground-water system, hydrologic stresses to the shallow ground-water system could adversely affect the lake system. In order to assess the effects of potential stresses on the lake, a study was completed by the U.S. Geological Survey, in cooperation with the Middle Genesee Lake Management District. The objective of the study was to identify areas that contribute ground water to the lake and estimate the hydrologic budget of the lake and hydraulic parameters affecting ground-water flow. A two-dimensional, steady-state analytic element model of the lake and surrounding area was developed using the computer code GFLOW. A parameter estimation model, UCODE, was used to optimize the calibration to measured water levels and streamflow. The calibrated model was used to evaluate the effect of three hypothetical stress scenarios on the stage of Middle Genesee Lake; the simulations were linked to UCODE, which formally incorporated parameter uncertainty into 95-percent confidence intervals around the simulated value. The scenarios included: (1) pumping from upgradient irrigation wells, (2) pumping from Lower Genesee Lake to lower lake levels, and (3) reduction in recharge resulting from development. The results of the simulations demonstrated that lake levels could be affected by hydrologic stresses in the shallow hydrologic system, with effects ranging from a 2.7 feet decline in lake stage resulting from pumping in Lower Genesee Lake to a 0.1 feet decline in lake stage from development in part of the upgradient recharge area. The range of lake stage decline increased when parameter uncertainty was included, from a decline of 3.1 feet for pumping from Lower Genesee Lake to no reduction in lake stage for the development in the recharge area. Whereas these simulated effects are within the natural variation in lake stage, they represent a systematic reduction of ground-water flow to the lake. Therefore, these hypothetical stresses are expected to establish a new, lower, baseline lake stage over which the natural variation due to climatic effects are added and subtracted.

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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.

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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.

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USGS1986

Hydrogeology and ground-water quality of Lannon-Sussex area, northeastern Waukesha County, Wisconsin

The Silurian dolomite aquifer in the Lannon-Sussex area of southeastern Wisconsin is overlain by glacial deposits, but is within 8 ft of the land surface over 15% of the study area. The proximity of the dolomite aquifer to the land surface makes it susceptible to contamination from man 's activities. Water from the aquifer was analyzed and several characteristics were monitored in a 30-sq-mi area of Waukesha County, including: water temperature, calcium, magnesium, potassium, strontium, alkalinity, chlorides, fluorides, sulfates, nitrites, nitrates, nitrogen, iron, manganese, hardness, and pH. The water is hard, commonly having a hardness of more than 350 mg/L as CaCO 3 , and high in iron, commonly containing more than 0.3 mg/L. However, nutrient concentrations are not high; nitrogen, greater than 8 mg/L; phosphorus, none detected; and potassium, greater than 4 mg/L. The chloride content of the water averages more than 50 mg/L indicating contamination probably from septic systems. The water quality varies over a time. High concentrations of chloride and, occasionally, of bacteria correlate with periods of groundwater recharge over a period of 17 months. Chloride concentrations were highest in water from wells where housing density is high. An attempt was made to relate water quality changes with depth to beds of cherty dolomite that are identified in geologic logs; it was postulated that these zones might be confining beds. Although the beds appear to extend over the area, no evidence was found that they are confining beds, other than reports of a few artesian wells. Water quality, indicated by chloride content, showed no significant relation to well bottom altitudes, casing bottom altitude, or well depth.

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USGS1979

Water-table map of Waukesha County, Wisconsin

A map (scale 1:100,000) was prepared of the water table in Waukesha County in southeastern Wisconsin using water levels from more than 1,700 wells. The work was done as part of a cooperative project between the U.S. Geological Survey, the University of Wisconsin-Extension, Geological and Natural History Survey, and the Southeastern Wisconsin Regional Planning Commission. The map shows the altitude of the water table in increments of 20 feet, with supplemental 10-foot contours. The altitude ranges from less than 670 feet at a point along the east border of the county to more than 1,000 feet above sea level at three points in the central part of the county. (Woodard-USGS)

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USGS1975

Ground-water resources and geology of Waukesha County, Wisconsin

Good-quality water is available from the sand-and-gravel, Niagara, and sandstone aquifers in Waukesha County, Wis. As much as 15 gallons per minute (0.95 litres per second) can be obtained from wells almost everywhere in the county. Several hundred gallons per minute are available from aquifers in the glacial drift that fill bedrock valleys to thicknesses of 300 feet (91 metres) or more. Estimated well yields from much of the surficial outwash in western Waukesha County exceed 500 gallons per minute (31 litres per second). Estimated well yields from most of the Niagara aquifer, a dolomite as much as 325 feet (99 metres) thick in the eastern two-thirds of the county, exceed 50 gallons per minute (3.2 litres per second). The sandstone aquifer underlies the entire county and ranges in thickness from about 400 feet (120 metres) in the northwest corner to about 2,400 feet (730 metres) in the southeast corner. This aquifer yields more than 1,000 gallons per minute (63 litres per second) to wells over most of the county and is the principal source for municipal and subdivision water. Ground water in Waukesha County is of good quality and is suitable for most uses. Most of the water is a calcium magnesium bicarbonate type, is very hard [more than 180 mg/l (milligrams per litre) hardness], and requires softening for some uses. The ground water locally contains iron and manganese concentrations that exceed the limits (0.3 and 0.05 mg/l, respectively) recommended by the U.S. Public Health Service (1962, p. 7). Water high in sulfate and dissolved solids (saline water) is present locally in the Niagara and sandstone aquifers. Water from one well contained excessive nitrate (more than 45 mg/l). With one exception, wells sampled at irregular intervals indicated no significant changes in their chemical characteristics with time. About 24.3 million gallons per day (1.06 cubic metres per second) of ground water was pumped in the county in 1970. Sixty-two percent was withdrawn from the sandstone aquifer. More than one-half of the latter amount was for domestic use, and more than one-third was for industrial and commercial uses.

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