Backwater Valve Program

Most of the time, the City's sewer pipes have adequate capacity to carry wastewater to the treatment plant. But during heavy, extended raining periods when the ground water is high, the capacity of some sections of the sewer system is exceeded. Ground water or surface water will enter older sewer pipes through cracks and, added to the wastewater flow, will exceed the space available in the pipe. When these conditions occur the water has to go somewhere. If it can't flow down the main pipe, it will back up into the service line and, possibly, all the way into the basement. This happened during the heavy rains in the February 1996 flood, and again in November and December 1996. 

A simple device in your sewer line, if properly maintained, can prevent wastewater from backing up into your basement. A one-way valve is installed in your line to allow wastewater to flow out, but it swings shut when wastewater tries to flow back in. 

The City of Corvallis Public Works Department has a program that may assist homeowners with the cost of installing backwater devices on their sewer lines. Backwater devices are designed to prevent wastewater from backing up into the sewer service line and into basements from the main trunk line. 

How Does the Program Work?

• Your house must have a basement and must be located in an area of the city subject to periodic basement flooding. Public Works Department staff can tell you if your home is in one of these areas. Call them at 541-766-6916 to find out if you are eligible for this program.
• Get the necessary City construction permits before any work is done. Call Development Services at 541-766-6929 for details.
• Hire a licensed plumbing contractor. You must show proof that you received project cost estimates from two different contractors and hired the contractor with the lowest estimated cost to do the job.
• When the project is done, pay the contractor. Then send the Public Works Department copies of all three cost estimates and the final invoice from the contractor. You are responsible for the first $100 of installation costs. After that, the City will reimburse you for up to $1500 of the remaining costs. Once the copies have been received and approved, a check will be sent to you in about 45 days.

The backwater prevention device belongs to you, and you are responsible for continued maintenance and repair. Ask your plumbing contractor for maintenance instructions. 

Liability 

The City's insurance company generally does not approve payment on claims for damages caused by sewer back-ups due to excessive wet weather conditions. The City assumes no liability should the backflow device fail to prevent basement flooding. 

For more information 

Contact the Public Works Department at 541-766-6916 to find out more about the program.