In light of the state’s decision to remove mandated water conservation targets as well as the success of water conservation within the City of Poway, the city is resuming an important program to maintain our water system previously curtailed due to the drought.
Known as flushing, this program is considered a standard industry practice by water agencies to maintain the highest level of water quality and protect public health. This process is critical to removing small particles that can accumulate inside water main pipes and potentially affect the quality of water.
Flushing is not a haphazard release of water, but rather the act of putting water to work to help keep the city’s system of pipes clean. Flushing pushes water out at a high velocity and scours the pipe walls to remove residue.
The amount of water discharged by Poway when it last regularly maintained a flushing program amounted to about 0.1 percent of the city’s total annual water use. To provide an idea of how much water that is, it would take 256 years to fill Lake Poway with the amount of water flushed each year.
Frequently Asked Questions
Where does the water go when the system is flushed?
Discharged water is generally channeled into storm drains, which lead to natural bodies of water. For that reason, it is dechlorinated to protect wildlife and sensitive species. In most areas, this water feeds existing streams and wetlands, benefitting the health and well-being of these bodies of water.
Why can’t the city capture the water flushed?
Recapturing this water would be ideal, but the reality is that it’s extremely difficult due to the velocity and duration of the water flow. It’s also not cost-effective. The cost of the water released during a typical flushing is $50, while the cost to capture it and transport it by water trucks would exceed $650 and take 10 hours for each flushing. It would roughly cost $625,000 to recapture all of the water flushed annually.
How can the city justify releasing that much water in light of the drought?
During the drought, the city put its flushing program on hold. But now that the regulations have been relaxed, the city has determined that it’s in the best interest of our water system to return to this “best practices” method of maintaining the high level of water quality that our residents have come to expect and deserve.
About the Poway Water System
- Lake Poway holds about 1 billion gallons of water.
- The city operates a modern water treatment plant and produces about 4 billion gallons of drinking water each year.
- Poway's drinking water meets or exceeds all state and federal standards for water quality.
- The city maintains about 269 miles of water pipe.