If you live near one of TVWD’s 21 water reservoirs, you’ve probably noticed just how quiet and unassuming they are. Little to no noise, no traffic, no fuss – just a reliable, behind-the-scenes neighbor that plays a major role in delivering clean, safe drinking water to our entire community. And like any good neighbor, we check in on them regularly to make sure they’re in great shape.
As we prepare to bring the new Willamette Water Supply System (WWSS) online as early as late-2026 and transition away from the Portland water supply, reservoir cleaning is especially critical. Making sure reservoirs are free of sediment and buildup allows the system to smoothly integrate water from our new source - the Willamette River at Wilsonville - while maintaining consistent water quality and supporting reliable service for homes and businesses across our service area.
Reservoirs do more than just store water – they help keep it flowing efficiently and at the right pressure, from neighborhoods on the valley floor to those as high as 1,045 feet. Keeping them clean not only supports water quality, it extends the life of the infrastructure, reduces wear and tear on pumps and pipes, and helps prevent costly repairs.
Every five years, each of our reservoirs gets a thorough, professional cleaning. Since a portion of our current water supply comes from the unfiltered Portland water system, natural sediment can settle at the bottom of reservoirs over time. Regular cleaning removes this buildup to help maintain water clarity, support system performance, and protect the quality of the water that comes out of your tap.
The cleaning process itself is impressive: professional divers enter the full reservoirs with disinfected, clean scuba and vacuum equipment – like cleaning a giant swimming pool – while the reservoirs stay online. A 2-million-gallon reservoir can be cleaned in one day, while larger 10-million-gallon tanks take around four days.
Chad V., a TVWD Water Works Operator with more than 20 years of experience managing the District’s distribution system (the pipes, valves, pumps, and tanks that deliver water to your home), oversees the cleaning work.
“Cleaning our reservoirs is critical not just for water quality today, but for the long-term health of the system,” Chad explains. “We’re protecting the infrastructure, supporting reliable service, and making sure our customers continue to receive safe, clean water every time they turn on the tap.”
By investing in this routine care, TVWD ensures these quiet neighbors keep working 24/7 to provide dependable water for your home and community.
