Workflow Evansville

Prevent Sewer Backups

Sanitary sewer backups can cost hundreds or thousands of dollars to repair. Sanitary sewer backups occur in either the City’s main sewer lines or in private sewer service lines, which you own and maintain. The guide below explains the responsibilities of the Evansville Water and Sewer Utility (EWSU) and property owners.

EWSU’s Guide to Sanitary Sewer Service

Causes of Sewer Backups

While the Utility tries to prevent backups, they still occur. Sewer backups may be caused by unapproved items entering the sewer system, outdated infrastructure or environmental impacts.

Materials from Homes and Businesses

There are many items, including “flushable” wipes, paper towels and sanitary items, that are unsuitable for our sewer system. They should never be flushed or washed down the drain. Learn more about what is and is not flushable

Environmental Intrusions

Tree roots and plant materials may cause breaks or cracks in sewer lines and mains. If you have large shrubs or trees with deep roots near your lateral sewer line, a plumber can determine if your service line has been or could be damaged. If you do not know where your lateral sewer line connects to the City’s system, call the Sewer Department at 812-421-2130 for help locating it.


Another frequent cause of blockages within the City’s system is vandalism. Report criminal activity by calling 812-421-2130 to alert the sewer department.

EWSU Efforts to Prevent Backups

EWSU does everything possible to prevent backups in the sanitary sewer system, including:

  • Regularly inspecting and cleaning sewer lines throughout the City. 
  • Injecting degreasing chemicals into lines in areas that are prone to stoppages, such as those near restaurants, apartments or high-density housing developments.

What to Do if You Have a Sewer Backup

Stop the Flow of Sewage

If the backup occurs in a City-maintained line, the wastewater will normally flow out of the lowest possible opening. In some homes – especially those with basements, or where the lowest level is even with the sewer lines – the wastewater may exit through your lowest drains and toilet.

You should quickly close all drain openings with stoppers and plugs. Please note that tub, sink and floor drains may need additional weight to keep them sealed. Avoid running water down your drains until the blockage has been cleared.

Report the Backup

Once you have plugged your drain openings, call 812-421-2130. Emergency crews are on call 24 hours a day, 7 days a week to assist you. The Utility may encourage you to check with your neighbors to determine if it is widespread in your neighborhood. 

You will be asked questions about the backup timing, location and properties at risk. City personnel will check for blockages in the main line and, if found, the blockage will be immediately cleared.

Clean Up and Repair the Damage

If the Utility's main line is not blocked, you will be advised to call a plumbing or sewer contractor to check your service line. To minimize damage to your property and health, cleanup should begin as quickly as possible. You may need to contact a business specializing in cleanup and restoration.