The Platte River watershed covers 198 square miles in central and east-central Grant County with a small portion in extreme western Iowa County. It has an area of about 194 square miles making it the second largest watershed in the basin.
The Platte River is the primary waterbody in the watershed. The river's historical records for the river record it to be deep enough to allow steamboats to ply its lower reaches. The upper reaches of the watershed are on Military Ridge, where the land is rolling and well suited to cultivation. The rest of the watershed's topography consists of narrow ridgetops, and steep slopes down to a narrow valley floor. The ridgetops are usually cultivated, while the steep valley slopes have been left in woods, similar to the pre-settlement condition.
There are about 215 stream miles in the watershed. There are 30.8 miles of cold water trout streams, approximately 60 miles of warm water sport fishery streams, 48.2 miles of warm water forage fishery streams, and 3.2 miles of limited aquatic life streams. The existing biological use of the remaining stream miles have not been determined, but are assumed to be full fish and aquatic life waters. Portions of four streams in the watershed, totaling 10.5 miles, are currently on Wisconsin's list of impaired waters, the 303(d) list. Those streams are Culver Branch, a short reach of Leggett Creek, a portion of Martinville Creek, and McPherson Branch. Each are on the list due to instream habitat impairment caused by nonpoint sources of pollution.
The Platte River, Crow, Culver, Lee, Leggett, and McPherson Creeks have been ranked high for nonpoint source pollution abatement projects.
Population, Land Use
There are three municipal Wisconsin wastewater discharge permitted facilities in the watershed. They are Orchard Manor with a discharge to a tributary of Austin Branch, Dickeyville (931) with a discharge to a tributary to Indian Creek, and Potosi-Tennyson that discharges to a wetland in Pool 11 of the Mississippi River. None of these are considered large or major municipal dischargers.
Dickeyville is growing at a relatively slow rate, so urban nonpoint source pollution from construction sites and stormwater runoff is not a major concern. Care still needs to be taken to properly control erosion from construction sites in the community. The wastewater treatment plants in the watershed do not constitute a threat to water quality as long as they are properly operated and maintained.
Public recreation in the watershed is limited by lack of public lands. Access to streams is scattered throughout the watershed and at road crossings.
Nonpoint and Point Sources
Agriculture is the dominant land use in the watershed and over 70% of the watershed's area is actively farmed (Fix, 1991). The watershed has many acres of intensively cropped farmland on highly erodible land. Stream bank erosion, from overgrazing streambanks or flooding, is also a major problem (Grant County, 1997). The Platte River watershed has one of the highest livestock concentrations in Wisconsin (ibid.). Runoff from problem barnyards and feedlots add to the sediment and nutrient problems in receiving surface waters. Two best management practices can be implemented to protect streams. One is providing stream buffers to stabilize stream banks, provide habitat, and filter out pollutants which otherwise would reach the stream (Lyons et. al., 2000b). A second practice that provides a similar result is rotational grazing (Lyons,et.al., 2000a).
Grant County LCD and the county office of the NRCS jointly initiated a USDA EQIP project in the Platte River Watershed (Environmental Quality Incentives Program), in the summer of 1998. Average soil loss for cropland in the Platte River watershed is estimated at eight tons/acre/year (Grant County, 1997) which compares with the tolerable (T) or target goal for soil loss in the watershed of five tons/acre/year. The water resources objectives of the Platte River watershed EQIP project are to obtain water quality, fish and wildlife habitat improvements by reducing sheet and rill erosion, streambank erosion, and manure and cropland runoff through a variety of farm management best management practices, including contour farming, conservation tillage, rotational grazing, grade stabilization structures, streambank stabilization, sediment basins, filter strips, manure storage, nutrient management, fencing and livestock exclusion (ibid.).
Nonpoint and Point Sources
Nonpoint Source Pollution - Based upon watershed reconnaissance conducted in the fall of 1997 and spring of 1998, monitoring streams in the watershed, and professional judgment of DNR staff, there are still a number of land management problems, including soil erosion from cultivated fields, overgrazing of streambanks, and exposed and eroding streambanks, around smaller cool and cold water streams in the upper portion of the Platte River watershed. The current work involved in the Platte River EQIP project should help to address some of the problem sites in the watershed. However, there is a continued need to consider these streams for small-scale nonpoint source pollution abatement projects as well.
A major reconstruction of US Highway 151 from Dickeyville to Belmont is scheduled to begin in the year 2002. Sediment coming from the site could threaten instream habitat and fisheries of nearby streams if adequate erosion control measures are not installed and properly maintained. Because of the topography of the area such measures may need to go beyond the standard Wisconsin Department of Transportation measures. The stream in this watershed potentially threatened is Indian Creek near Dickeyville.
There are three municipal Wisconsin wastewater discharge permitted facilities in the watershed. They are Orchard Manor with a discharge to a tributary of Austin Branch, Dickeyville (931) with a discharge to a tributary to Indian Creek, and Potosi-Tennyson that discharges to a wetland in Pool 11 of the Mississippi River. None of these are considered large or major municipal dischargers. Dickeyville is growing at a relatively slow rate, so urban nonpoint source pollution from construction sites and stormwater runoff is not a major concern. Care still needs to be taken to properly control erosion from construction sites in the community. The wastewater treatment plants in the watershed do not constitute a threat to water quality as long as they are properly operated and maintained.
The Platte River Watershed is located in both the Western Coulee and Ridges Ecological Landscape and the Southwest Savanna Ecological Landscape.
The Western Coulee and Ridges Ecological Landscape in southwestern and west central Wisconsin is characterized by its highly eroded, driftless topography and relatively extensive forested landscape. Soils are silt loams (loess) and sandy loams over sandstone residuum over dolomite. Several large rivers including the Wisconsin, Mississippi, Chippewa, Kickapoo and Black flow through or border the Ecological Landscape.
Historical vegetation consisted of southern hardwood forests, oak savanna, scattered prairies, and floodplain forests and marshes along the major rivers. With Euro-American settlement, most of the land on ridgetops and valley bottoms was cleared of oak savanna, prairie, and level forest for agriculture. The steep slopes between valley bottom and ridgetop, unsuitable for raising crops, grew into oak-dominated forests after the ubiquitous presettlement wildfires were suppressed. Current vegetation is a mix of forest (40%), agriculture, and grassland with some wetlands in the river valleys. The primary forest cover is oak-hickory (51%) dominated by oak species and shagbark hickory. Maple-basswood forests (28%), dominated by sugar maple, basswood and red maple, are common in areas that were not subjected to repeated presettlement wildfires. Bottomland hardwoods (10%) are common in the valley bottoms of major rivers and are dominated by silver maple, ashes, elms, cottonwood, and red maple. Relict conifer forests including white pine, hemlock and yellow birch are a rarer natural community in the cooler, steep, north slope microclimates.
The Southwest Savanna Ecological Landscape is located in the far southwestern part of the state. It is characterized by deeply dissected topography, unglaciated for the last 2.4 million years, with broad open hilltops and river valleys, and steep wooded slopes. The climate is favorable for agriculture but the steep slopes limit it to the hilltops and valley bottoms. Soils are underlain with calcareous bedrock. Soils on hilltops are silty loams, sometimes of shallow depth over exposed bedrock and stony red clay subsoil. Some valley soils are alluvial sands, loams, and peats. Some hilltops are almost treeless due to the thin soil while others have a deep silt loam cap.
Historic vegetation consisted of tall prairie grasses and forbs with oak savannas and some wooded slopes of oak. Almost three-quarters of the current vegetation is agricultural crops with lesser amounts of grasslands, barrens, and urban areas. The major forest types are oak-hickory and maple-basswood. High-quality prairie remnants occur on rocky hilltops and slopes that are not farmed. Some prairie pastures and oak savannas still exist. The grassland areas harbor many rare grassland birds, invertebrates, and other grassland species. Relict stands of pine occur on bedrock outcroppings along some stream systems.
Monitor biology on WBIC: 954200
Conduct biological (mIBI or fIBI) monitoring on Unnamed, WBIC: 954200, AU:5727611
Monitor biology on WBIC: 951700
Conduct biological (mIBI or fIBI) monitoring on Unnamed, WBIC: 951700, AU:5727127
Document monitoring conducted to de-list from impaired waters list.
Martin Branch, Martinville Creek and Rogers Branch TMDLs
The Wisconsin Department of Natural Resources (WDNR) developed TMDLs for TSS and phosphorus for Martin Branch, Martinville Creek, and Rogers Branch in Grant County, Wisconsin.
Martinville Creek TMDL
Martinville Creek TMDL
Watershed History Note
Founded in 1852 by Gabriel Hail and John Albrecht, the Potosi Brewery began as a small brewery quenching the thirsts of area farmers, fishermen and miners. In 1886 Adam Schumacher bought the brewery and started brewing beer. In 1906, the Potosi Brewing Company was founded by Adam and his brothers Nicholas and Henry. At its peak, the Potosi Brewery had grown to be the fifth largest in Wisconsin, shipping a variety of labels including Good Old Potosi, Holiday, Garten Brau, Augsburger and others to destinations throughout the United States. In 1972 the brewery ceased operations and closed its doors.
The restoration of the Potosi Brewery began in 1995 when Gary David bought the ruined Brewery Bottling buildings. The nearly one square block of buildings has just suffered a major fire and most of the buildings were a total loss. After three years to rebuild what had been destroyed, attention was turned to the Brewery itself. Mr. David, with friends and family, worked with the community to create the Potosi Brewery Foundation in 2000.
In 2004, the Potosi Brewery Foundation was selected by the Breweriana Association to be the home to its national museum. The National Brewery Museum and Library opened in the village on the site of the Potosi Brewery in 2008. The National Brewery Museum is a world-class facility dedicated to preserving the artifacts and memories of America's breweries.