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Milwaukee River Basin Explained

Milwaukee River Basin Facts

Milwaukee River Basin is located in portions of seven counties, contains (entirely or portions of) 13 cities, 32 towns, 24 villages and is home to about 1.3 million people. The southern quarter of the basin is the most densely populated area in the state, holding 90% of the basin’s population.

The river basin is divided into six watersheds.

The Milwaukee River Watersheds occupy 2/3 of the basin area (584 square miles) and consist of:

The other three watersheds are named after the major rivers they contain and they occupy the remaining 1/3 of the basin. They consist of:

Collectively the six watersheds contain about 500 miles of perennial streams, over 400 miles of intermittent streams, 35 miles of Lake Michigan shoreline, 57 named lakes and many small lakes and ponds. Wetlands encompass over 68,000 acres, or 12% of the basin land area.

River Inhabitants

The number of fish found in the Milwaukee River Basin vary depending on if you count Lake Michigan species or not. Some studies count Lake Michigan species that enter the river such as Coho and Chinook salmon, but do not count fish that might stray into the lower part of the river such as lake trout. A rough cross-reference reveals 54 different species of fish.

However, there are many other inhabitants apart from fish in the Milwaukee River Basin. Invertebrates, for example, play a significant role in the ecosystem of a river. In fact, the types of critters you might find can help determine the health of a stream. The abundance of some invertebrates signals that the river is in good health, while an abundance of others is a bad omen. click here.

Milwaukee River Basin’s Past

Before intensive settlement, the Milwaukee River Basin was much different than it is today. Historic settlements of four Native American groups—the Fox, Mascouten, Potawatomi and Menominee—were documented along the Milwaukee River, and remained in the area for a short time after their lands were ceded to the United States around 1833. Some of these groups even became involved in the fur trade with French explorers during the 1700 and 1800s. Pere Jacques Marquette was the first European explorer known to have visited what is now Milwaukee. He and the other explorers who followed him found an area rich with upland forests of maple, beech and basswood, and lowland areas dominated by tamarack, cedar and ash.

In addition to the forests, the basin was water and wetland rich. The abundant resources of the forests, rivers and lakes were catalysts for the first settlers’ attempts at economic development in the basin. The southernmost portions of the basin, now known as the Milwaukee area, were soon settled and incorporated, while many of the forested riverbanks were cut for lumber or cleared for farming. Further north in the basin, the land was rapidly deforested and cleared for agriculture. The relatively flat landscape and rich soils that were formed by the glaciers in many areas of the basin allowed the settlers to farm a variety of crops. By the mid-late 1800s, farming was the main activity in the upper basin, while mill operations were the first industries. The Milwaukee River and Cedar Creek served to provide excellent hydropower for the mills.

The Milwaukee River Basin Currently

The Natural Heritage Inventory has documented 16 endangered, 26 threatened and 65 special concern plant and animal species along with 30 rare aquatic and terrestrial communities within the basin. The Southeastern Wisconsin Regional Planning Commission (SEWRPC) identified over 18,000 acres of high quality natural communities and critical species habitats remaining in the basin. About 18% of the land area of the basin is covered by urban uses, while the remainder is considered rural. Agriculture is still dominant in the northern half of the basin.

Lake Michigan supplies drinking water to about 70 percent of basin residents as a function of population size. The remainder of the population receives their drinking water from groundwater sources. However, as people move to the more rural areas of the basin, groundwater quantity and quality issues will become more important.

(Most information above culled from the WDNR’s State of the Basin Report. For more information on WI River Invertebrates click here.)

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