When Detroit underwent rapid industrialization beginning at the turn at the twentieth century, much of the pollutants from the growing industries found their way into the Detroit River and had devastating consequences on the ecosystem.
 When the Detroit River became so polluted as to warrant federal intervention, Congress declared Grassy Island and the surrounding area as part of the Wyandotte National Wildlife Refuge in 1961.
 However, larger shipping lanes were needed in the Detroit River and its main tributary, the River Rouge, with the increase of commercial shipping and larger freighters during this time.
 The U.S. Army Corps of Engineers took control of Grassy Island from 1960–1982 and used it as a disposal facility for millions of cubic meters of sediments dredged from the nearby River Rouge for better navigation of that river.
 Dikes were constructed around Grassy Island to hold the sediments— much of which were heavily contaminated from nearby industries.

When the dredging project was completed, Grassy Island swelled from its original 6 acres (2.4 ha) to 72 acres (29 ha).
 Because of the island's massive expansion, it can be considered an artificial island, as no real remnants of the original island are seen today.
 The mouth of the River Rouge was effectively diverted to an easier route (creating the artificial Zug Island in the process) with all the sediments from this new River Rouge route being dumped at Grassy Island with no regard to the amount of pollutants in the soil.
 The island now has an unnatural appearance and composition.
 Its sides are steep earthen dikes used to hold up the island, and this can pose a variety of hazards to those who attempt to dock boats at the shore or walk on the island.
When Detroit underwent rapid industrialization beginning at the turn at the twentieth century, much of the pollutants from the growing industries found their way into the Detroit River and had devastating consequences on the ecosystem.  When the Detroit River became so polluted as to warrant federal intervention, Congress declared Grassy Island and the surrounding area as part of the Wyandotte National Wildlife Refuge in 1961.  However, larger shipping lanes were needed in the Detroit River and its main tributary, the River Rouge, with the increase of commercial shipping and larger freighters during this time.  The U.S. Army Corps of Engineers took control of Grassy Island from 1960–1982 and used it as a disposal facility for millions of cubic meters of sediments dredged from the nearby River Rouge for better navigation of that river.  Dikes were constructed around Grassy Island to hold the sediments— much of which were heavily contaminated from nearby industries.
When the dredging project was completed, Grassy Island swelled from its original 6 acres (2.4 ha) to 72 acres (29 ha).  Because of the island's massive expansion, it can be considered an artificial island, as no real remnants of the original island are seen today.  The mouth of the River Rouge was effectively diverted to an easier route (creating the artificial Zug Island in the process) with all the sediments from this new River Rouge route being dumped at Grassy Island with no regard to the amount of pollutants in the soil.  The island now has an unnatural appearance and composition.  Its sides are steep earthen dikes used to hold up the island, and this can pose a variety of hazards to those who attempt to dock boats at the shore or walk on the island.
Grassy Island