By Vince Gerasole

(CBS) — What’s floating in the urban waters of the Chicago River is an attempt to bring back its natural life.

“In the ‘70s, the water was so bad it was considered poisonous in a way,” says Zachary Damato of the advocacy group Urban Rivers.

It begins in the shell of a burned-out warehouse, where volunteers who know the river is now cleaner plant the seeds of a hopeful future.

Native plants are being placed into what will become a floating wetlands to hopefully attract wildlife.

“What we want to happen is to have these things attract fish. Fish will come underneath, they’ll eat the roots. The plants will grow, birds will eat the plants. It will start to jump-start the ecosystem,” Nick Wesley, also of Urban Rivers, tells CBS 2’s Vince Gerasole.

In all, the not-for-profit is creating 166 linear feet.

Volunteers will continue to assemble the wetlands Saturday.