The Corbett Water District spends thousands of dollars each year to ensure the safety of our drinking water. A vital link in this effort is the Corbett Water District's Cross-Connection and Backflow Prevention programs. 

Water distribution systems are designed so that water flows in one direction from the treatment plant to the customer. 

Cross-Connections are any unprotected actual or potential connection or structural arrangement between a public or a consumer's potable water system and any other source or system through which it is possible to introduce, into any part of the potable system, any used water or substance other than the intended potable water. Bypass arrangements, jumper connections or any other temporary or permanent connections through which backflow can occur are considered to be cross-connections. 

Backflow is the undesirable reversal of flow of water or mixtures of water and other liquids or substances into the distribution pipes of the potable supply of water from any source or sources.

Federal and State laws require Water Purveyors to protect their system from cross-connections and backflow. To do this, we work closely with consumers, architects, contractors, and engineers to ensure that all those who are required to, comply with cross-connection control and/or backflow prevention requirements. If you have been contacted by the Corbett Water District and know you need a backflow prevention assembly installed or tested, see the Oregon State of approved backflow testers website at, for a list of certified testers.

It is suggested to contact the City of Gresham permit department at        503-618-2891 to discuss permit requirements.

For questions regarding assembly requirements and approvals for meter protection, fire protection or for more information about this program, please contact the District office at 503-695-2284 or via email at


Suggested installation guidelines are below. Please note that a certified plumber will have the ability to install backflow assemblies.

1. Shut off the meter service on the District side of the meter.
2. Remove the back side of the service line. Cut about 5” off.
3. Rotate meter about 15 degrees, so you can install the “s” tube on the back side of the water meter.
4. With an adapter so the double check can be installed on the downstream end of the “s” tube, tie into PVC or copper compression. 
5. The meter and double check will fit inside the Corbett Water District meter box and the touch read unit will be installed in the green plastic meter lid. 
6. The meter / double check will be rotated about 15 degrees from the perpendicular original location from the street when completed.

If you need a larger meter box, with the hole drilled out for the touch read unit, please contact the District office to exchange the smaller meter box at no cost to the customer. 

Listed below are some vendors that carry backflow assembly parts for your convenience only. Corbett Water District has no affiliation with any of the following companies. 

Please make sure that you purchase a "lead free" assembly.
Ferguson Plumbing Supply (Gresham).........503-695-5455
Ferguson Plumbing Suppy (Portland)...........503-240-6747
HD Supply Waterworks................................503-620-9123
H.D. Fowler & Co.........................................503-656-3900
Keller Supply................................................360-696-4377