The La Crosse-Bad Axe River Basin encompasses approximately 1,000 square miles in southwest Wisconsin. This basin lies entirely within the portion of Wisconsin that was not flattened by the glacial ice drifts, also known as the driftless area. The basin is divided into six watersheds for water resource management purposes: Upper La Crosse River, Little La Crosse River, Lower La Crosse River, Coon Creek, Bad Axe River, and the Rush Creek watersheds. Three watersheds drain to the La Crosse River, while the other three drain directly toward the Mississippi River.
The basin includes parts of Crawford, La Crosse, Monroe and Vernon Counties. Major cities and villages in the basin include La Crosse, Onalaska, Sparta, Prairie du Chien, Viroqua, Westby, Genoa, Chaseburg, Coon Valley, Cashton, DeSoto, Stoddard, Rockland, Bangor and Fort McCoy. Approximately 106,000 people live in the La Crosse-Bad Axe River Basin, La Crosse County being the most populous. The basin population increased an estimated 8% between 1990 and 2000, a little higher than the state average of 7.3%.
The La Crosse-Bad Axe River basin covers nearly 1,000 square miles within the driftless, or unglaciated, portion of the state. Typical terrain consists of ridges with steep slopes and narrow stream valleys, characteristic of the coulee region. An elevation difference of 700 feet from valley floor to ridgetop is not uncommon. Soils are silt loam (loess) and sandy loam over sandstone and dolomite.
Aside from agricultural crops, vegetation in the basin consists of oak forest, degraded oak savanna, grassland, dry prairie, and bottomland hardwoods. Exposed sandstone and dolomite cliffs are common throughout the basin. The major land use is agriculture, including dairy and beef farms, located on ridge tops as well as stream valleys. Highly erodable lands, common in the driftless area, are either in hardwoods or in set-aside programs such as the Conservation Reserve Program (CRP). Wooded slopes are often managed for oak/hardwood production, however due to high tax assessments of non-agricultural land, more wooded slopes are now being grazed.
The La Crosse-Bad Axe River Basin contains approximately 850 miles of streams and rivers. Due to the steep topography, no natural lakes exist in the basin; however, a fair number of man-made impoundments can be found. Again, due to steep topography, isolated wetlands are rare, but some relatively large expanses of wetlands are located adjacent to the larger rivers in the basin.
Black-Buffalo-Trempealeau River Basin
The Black-Buffalo-Trempealeau River Basin covers approximately 3852 square miles of land in West Central Wisconsin. The Basin includes parts of Buffalo, Clark, La Crosse, Jackson, Monroe, Trempealeau, and Taylor Counties.
- Encompasses around 2.5 million acres
- Includes about 3,500 miles of stream and 82 lakes and impoundments
- Has almost 300,000 acres of wetlands
- Is home to historic Native American lands
- Has nearly 600,000 acres of county, state, and federally-owned public land.
- Supports a population of approximately 80,000.
- Includes some of the roughest terrain in the state.
The area from eastern Jackson County to the northern tip of the basin in Taylor County was covered as late as 10,000 years ago with Ice Age glaciers. Home to the headwaters of the Black River, several lakes in Taylor County are kettle holes that were created by glaciers and have since filled with groundwater. These glaciers scraped the granite underlayers and deposited silty soils. Today, the rich, poorly drained soils are used mainly for agriculture, though they are perhaps better suited to forestry, and also make up most of the wetlands in the basin.
Early vegetation in this northern section of the BBT was made up predominantly of Northern Mesic Forest, or maple, hemlock, and yellow birch, except in the area of the Sand Plain. The sandy alluvial plains created by glacial Lake Wisconsin provided the ideal setting for Pine Barrens and Pine Forests.
The Coulee Section includes most of Buffalo, Trempealeau, and La Crosse Counties as well as western Jackson County. Better known as the Driftless Area, this plateau has been dissected by a maze of high, narrow ridges and steep, broad coulees worn down by streams. A layer of wind-spread silt covers most of the Coulee Section, while sand and gravel carried from the uplands covers the valleys.
The Coulee Section is also part of a region of the country known as the Prairie-Forest Border, forming the transition zone between the plains to the south and west and the forests to the north and east. Before European settlement and the resulting fire suppression, the vegetation in this region consisted mostly of oak savanna and southern oak forest.
At one time, 78 percent of the Basin was covered by forests. Land use in the Basin has changed over the years since European settlement though. Currently, unlike many other basins in the state, less than 1percent of the Basin’s land is considered to be urban. Most of the remaining rural lands of the Basin are split evenly between cropland or pasture and forest .
About 3,500 miles of streams and 82 lakes and impoundments make up the water resources of the Black, Buffalo, Trempealeau Basin. Of these total stream miles, 604 miles are designated cold water streams that are capable of supporting, to some degree, a trout fishery. Of the 82 Lakes and impoundments, only 20 occur naturally and these are confined primarily to the northernmost part of the Basin in Taylor County. These naturally occurring lakes form the headwaters of the Black River.
One major resource in protecting the streams and lakes in the Basin is wetlands. Nearly 300,000 acres of wetlands store excess water, protect shorelines from erosion, assist in groundwater recharge and discharge, and provide vital habitat for fish and wildlife.
The northern portion of the basin, generally including the area north and east of Black River Falls, is made up of a granite bedrock overlayed by clay soils. As a result, the groundwater in this area flows in the cracks, or aquifers, between layers of granite. These aquifers can be both deep and difficult to find.
In the southern portion of the basin, that area south and west of Black River Falls which is also considered to be the unglaciated, or Coulee Region. The bedrock here is made up mostly of sandstone, which is extremely porous. Groundwater can be much easier to locate and drill to in this area of the basin, but it also has a much greater potential for contamination, because the sandstone is not very effective in filtering surface waters that permeate it. A variety of land uses can release contaminants that travel through the sandstone to the water table, potentially causing problems with both private and municipal drinking water supplies.
Because of issues like these that impact drinking water, communities across the basin are developing wellhead protection plans that will help them minimize the potential for contamination.
The Black-Buffalo-Trempealeau Basin offers a wealth of wildlife viewing, hunting, and trapping opportunities, from the whitetail deer that is so common across the state, to the rare and protected timber wolf. Wildlife areas, fishery areas, parks, and forests provide a variety of habitats spread over thousands of acres for wildlife to thrive in their natural surroundings.
The Black-Buffalo-Trempealeau Basin provides many areas of rare habitat to species that are endangered or threatened state-wide, federally, and even globally. Of those species that are listed in the state as endangered, threatened, or special concern, 27 percent are found in the Basin.
Endangered species are those species whose continued existence in Wisconsin is in jeopardy. Threatened species appear to authorities, within the foreseeable future, to become endangered. Species of special concern, however, are those species for which some problem of abundance or distribution is suspected but not yet proven.
A variety of problems can lead to the significant decrease of certain wildlife populations. For example, the Karner blue butterfly, a federally endangered butterfly found in the Basin, experienced a major population decrease during the last century because of loss of barrens habitats, open, prairie-type habitats with scattered trees, usually oak or pine. Many rare mammals depend on having a broad expanse of forested land in which to live, hunt, and reproduce. Each fish species has certain habitat requirements, including dissolved oxygen levels, water temperature, stream bottom, food supply, and more. When one or more of these requirements are not being met, stress is put on the population.
In the Black-Buffalo-Trempealeau Basin, barrens habitats are encouraged through prescribed burning practices, propagation of important, native plant species, and control of invasive species. Thousands of acres of county, state, and federal forest land in the Basin offer connected wild areas for wildlife that require a broad range to survive. Many streams offer the right combinations of water quality, temperature, and habitat for rare species in the state.