Industrial chemicals, fabric dyes, human poop — these waste products all need to go somewhere. And up until the early 1900s, they mostly ended up in Baltimore’s rivers and harbor. In this era, few houses had indoor plumbing, and the ones that did piped straight into nearby streams. Families dumped their bathwater and dishwater into the gutters. Hired “night soil men” hauled the contents of backyard privies out of the city by barrel, cart, and barge, to fertilize nearby farms. Butchers, brewers, soap factories, and sugar refineries pumped their effluent directly into Baltimore’s waterways, mixing with street runoff from horse manure and overflowing outhouses. Imagine the scent of the Inner Harbor, if you dare!

After decades of odor complaints and disease outbreaks, the city in 1905 began work to address the problem. A comprehensive plan to build two sewer systems adapted cutting-edge designs from similar projects around the country. Sanitary sewers would eventually connect most Baltimore residences to indoor plumbing and wastewater treatment, while a separate storm sewer system would drain the city’s streets and reduce flooding.

Baltimore’s abused rivers became the backbones of these storm sewers. The city transformed Sumwalt Run and miles of other streams into buried storm drains that channeled rainwater off of city streets. This new system employed the most advanced engineering of its day. Tunnel sizes and slopes were carefully calculated to accommodate water from the heaviest rains.

Although ingenious, engineers could not predict the weather. A torrential storm in 1915 swamped sewers and underground streams throughout the city, collapsing the Harris Creek tunnel and flooding eight acres of Patterson Park. In the 21st century, more frequent storms fueled by climate change regularly overwhelm the city’s aging stormwater and sanitary sewers, causing flooding, sinkholes, and sewage overflows. Long-overdue sewer maintenance, upgrades, and measures to reduce stormwater run-off (such as more green infrastructure) are needed to prepare Baltimore and other cities for a changed climate.