Moving water in rivers and streams provide more oxygen to sustain fish and other wildlife such as Northern Leopard Frog (Rana pipiens) and Great Blue Heron.

Insects such as mayflies, dragonflies, and damselflies spend their juvenile stage in streams, and serve as living indicators of water quality.

Many streams, including the DuPage River, have been channelized for navigation and irrigation, losing their value as wildlife habitat.