• Home
  • How We Work
  • Where We Work
  • News Room
  • About Us
  • My Nature Page

The Nature Conservancy in Africa - Conservation in Africa

The Nature Conservancy in Asia Pacific - Conservation in Asia-Pacific

The Nature Conservancy in the Caribbean - Conservation in the Caribbean

The Nature Conservancy in Central America - Conservation in Central America

The Nature Conservancy in North America - Conservation in North America

The Nature Conservancy in the United States - Conservation in the United States

The Nature Conservancy in South America - Conservation in South America

River Raisin Watershed

The River Raisin flows through preserves at Sharon Hollow and Ives Road Fen.
River Raisin
© Harold E. Malde

Why the Conservancy Selected This Site
Draining a watershed the size of Rhode Island, the River Raisin once served as a waterway for trade and travel for early settlers. Even now, the river provides lifeblood for the communities settled around it. But the river does more than support the communities near its banks. At least 84 fish species feed off the 216 aquatic insect species the river supports. Another 21 species of freshwater mussels make the River Raisin one of the most productive mussel habitats in the state, reaffirming the river’s good ecological health, as mussels are indicators of a healthy river system. Rare and endangered species also live in and around the River Raisin, such as reptiles and bats.

Learn about field trips in the River Raisin Watershed.

Threats
With development pressure coming from both Toledo and Detroit, time is of the essence to protect what we can of one of the very best warmwater rivers in Michigan. Invasives species, altered hydrology, water quality degradation, and loss of habitat resulting from conversion to agriculture all affect the quality of the River Raisin.

Our Conservation Strategy
The Conservancy works with the Washtenaw County Parks and Recreation Commission and local land trusts to help protect vital tributaries to the river, including wetlands and streams, in addition to the river corridor. For example, the Conservancy and Washtenaw County just completed a partnership that will turn much of a newly purchased 245-acre property into a natural area along the banks of the River Raisin. Together with local partners, we can now proudly boast of protecting roughly six miles of the river and more than 1500 acres in the watershed, including our Ives Road Fen and Nan Weston preserves.

What the Conservancy Has Done/Is Doing
The Nature Conservancy’s protection efforts began in 1983 with the purchase of 22 acres. That land parcel has grown to become the 249-acre Nan Weston Nature Preserve at Sharon Hollow. From streams lined with silver maple and red ash to swamps filled with elm and yellow birch, Sharon Hollow encompasses a vital floodplain forest adjacent to the River Raisin and provides extensive habitat for migratory birds, amphibians, and an array of wildflowers.

Meandering downstream on its way to Lake Erie, the River Raisin meets the Conservancy’s Ives Road Fen Preserve near Tecumseh. This 660-acre preserve is a unique wetland community in which wet, spring-fed prairie fen blends into floodplain forest along the river. Fens are globally significant, and increasingly rare, wetlands that receive water from underground alkaline springs rather than from precipitation. This mineral-rich, cool water flows in rivulets under the thick grasses and sedges of the preserve and empties into the River Raisin at its eastern edge. The fen provides habitat for many of the watershed’s rare species as well as migratory and breeding birds.