City of Kansas City, Water Services

Overflow Control Program

The Overflow Control Program (OCP) is a commitment by KC Water to meet regulatory requirements, as outlined in the Consent Decree, to reduce overflows from combined sewer systems and prevent overflows from separate sewer systems.

Reducing and preventing overflows from Kansas City’s sewer systems creates a cleaner, healthier environment for our community and improves the quality of the water that is returned to area waterways.

The OCP is the largest infrastructure investment in Kansas City’s history. The program will be implemented over a 25-year time period by completing a list of improvements that can be found in the Overflow Control Plan and in our Overflow Control Program Roadshow.

Interested in learning more? Please click HERE to sign-up to receive OCP updates.

For a list of current projects and annual reports please click HERE.

What does it mean to have combined and separate sewer systems?

Kansas City’s sewer system is made up of combined and separate sewers. In a separate sewer system, stormwater and wastewater are collected in two different pipes.  The wastewater is routed to a wastewater treatment plant for treatment and the stormwater flows directly to nearby rivers and streams without treatment.   A combined sewer system collects stormwater and wastewater in the same pipe.  The wastewater and stormwater collected is routed to a wastewater treatment plant for treatment.

What is a sewer overflow?

During periods of moderate or heavy rainfall, sewer systems can reach capacity, overflow, and discharge a mixture of wastewater and stormwater into our streams and rivers.

The discharge of water from combined sewer overflows is not uncommon, and some overflow from these systems is allowed under national discharge permits.

Separate sewer systems are not typically designed to overflow, but broken joints, pipes, and manholes near separate sewer systems which can allow stormwater to enter the pipes, causing the separate system to overflow during heavy rainfall.

The OCP will address overflows from both the combined and separate sewer systems by reducing the number of combined sewer system overflows by 88% and repairing separate systems to eliminate overflows.

Did you know?

Most of Kansas City’s wastewater infrastructure is made up of separate sewer systems. KC Water maintains 260 square miles of separate sewer systems, and 58 square miles of combined sewer systems. The combined sewer systems can be found in the oldest parts of Kansas City. Some of our combined sewer systems, dating back to 1863, are still in use today!


Basement Backup Survey
Smoke Testing Fact Sheet
Smoke Testing Video

Completed Projects (Please click HERE for a list of current projects):

Round Grove Force Basin Force Main Re-establishment
Round Grove Basin Infiltration and Inflow Reduction
Middle Blue River Basin Green Solutions Pilot Project