Park No. 597 / SEPA Station #1 Natural Area, Chicago

A Natural Area Around A Waterway Machine

The Chicago Park District describes SEPA Station #1 as a Side-stream Elevated Pool Aeration system that uses pumps and waterfalls to improve dissolved oxygen in the Calumet River-Main Channel. That makes the site both ecological landscape and waterway technology.

The Park District began ecological restoration and management around the pool after a 2018 lease agreement with the Metropolitan Water Reclamation District. The resulting landscape is a useful Southeast Side example of public land being repurposed for habitat rather than only access or operations.

The Eaglets Change The Record

In May 2026, the Park District announced that bald eagle hatchlings had been observed at the site, believed to be Chicago's first successful bald eagle hatchlings inside city limits in more than a century.

The story quickly shifted from celebration to protection. WTTW reported that the Park District put barriers in place and closed a popular trail after the nest drew too much attention. That second turn is part of the record: urban wildlife success can create its own access conflict.

Research Questions To Carry Forward

Future documentation should watch how the park balances habitat protection, public curiosity, trail access, and the operational needs of the aeration station.

The site also belongs in any broader Calumet River research frame, especially work on industrial river corridors, MWRD infrastructure, brownfield-adjacent habitat, and the Southeast Side's uneven access to restored public nature.