Beaverton aims to conserve water with Purple Pipe Program
Beaverton is working on an innovative water project that will conserve water, save money and use groundwater and stormwater for irrigation in the South Cooper Mountain area.
The Purple Pipe Program, as city officials are calling it, is the first of its kind in Oregon. It will eventually use treated stormwater and native groundwater for irrigation, according to program manager Priya Dhanapal.
"This has been attracting a lot of attention throughout the West Coast. (Consultants for) the city of Seattle actually connected with us to ask how we do it and what we're doing because they want to implement something similar," Dhanapal said.
Currently, Beaverton gets most of its water from the Tualatin River and from aquifer storage underground. Later this decade, it is expected to tap the Willamette River as an alternative water source through the Willamette Water Supply System, in which it is partnering with Hillsboro and the Tualatin Valley Water District.
All of this water is treated to be used for drinking water and in homes across the city.
Potable drinking water needs to go through extra treatment processes, Dhanapal said, but if people are just watering grass and plants with it, the water don't need to be treated with chlorine or fluoride.
That's where the Purple Pipe Program comes in.
The additional water system will carry non-potable but clean water across the South Cooper Mountain area to be used for irrigation and recharging streams.
Without the Purple Pipe Program, drinking water is the only option for watering parks and yards, so adding this new water system makes sense for Beaverton in a few different ways, Dhanapal said.
Not only does the program save money by eliminating those extra treatment costs, but the project will be useful for environmental reasons, too.
When groundwater and stormwater are used instead, less water has to be taken from the Tualatin River.
"That's not only a cost avoidance, it is (saving resources) for the overall region, not just for us — that's why it's a reliable and sustainable source," Dhanapal said.
The stormwater treatment part of the project hasn't been set up yet, but when that happens within the next year or so, Dhanapal said the system will be using water that would've been wasted otherwise.
"The program helps fulfill a commitment that the city has made to increase its resiliency to climate change by making a real difference in terms of water uses for Beaverton water customers," Dhanapal said.
Beaverton Mayor Lacey Beaty said the city has been working on the project for a while as part of its climate action plan.
"It sometimes feels like water isn't a problem in Oregon because it comes out of the sky so much, but we have to fiercely protect our drinking water," Beaty said. "And when we use our drinking water to irrigate lawns and stuff like that, it's not the best and greatest use. … And we had an opportunity in South Cooper Mountain — where we were building a community from the ground up — to think creatively and do something new and different."
For now, the project will be contained just to South Cooper Mountain, and maybe future developments in Beaverton where other projects are going on, too. That way, it's cost-effective to add in the purple pipes at the same time.
The project is still in its early stages, and the cost is continuously evolving, Dhanapal said, but the latest estimate for the overall cost was about $19.5 million. The project is anticipated to be completed in summer 2023.
According to the Purple Pipe project website, the system will be paid for through system development charges, or SDCs, which are fees paid by developers and customers at the time of connection. The rest of the costs will come from city revenue, a grant from the state and any other grants the city can get for the project.
When the project is done, homeowners living in the area will also see utility bills for non-potable water, which will likely be lower than rates for potable water, but Dhanapal said no rates have been set so far.
So far, about 9,500 linear feet of purple pipe has been constructed near Mountainside High School and in surrounding neighborhoods.
For more information about the project and how it will affect residents, visit the project website at www.beavertonoregon.gov/1523/Beaverton-Purple-Pipe.
Editor's note: A previous version of this story provided an incorrect estimate of the overall project cost. The estimate is $19.5 million.
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