The city’s sewage system is more than 100 years old and was designed to discharge wastewater directly into area waterways when it becomes overloaded, a key reason water quality is poor in the Inner Harbor, Jones and Gwynns falls and the Patapsco and Back rivers. Cracked and broken pipes allow sewage to routinely flow into city waterways. When it rains, stormwater inundates the system, sometimes washing millions of gallons of water contaminated with untreated sewage into waterways.