Powell Butte Reservoir #2 project goes into winter hibernation

33,000 truckloads of dirt later … find out what happens now, and when work will start up again – at this, one of Portland Water Bureau’s biggest projects in recent history. Fascinating photos will help you understanding the size and scope of the project …

Overlooking the massive hole excavated this year, Teresa Elliott, Portland Water Bureau’s principal engineer in charge of constructing Powell Butte Reservoir #2 talks about the project with Bureau spokesman Tim Hall.

Story and photos by David F. Ashton
With the federal government demanding that Portland shut down or cover its open drinking water reservoirs, the Portland Water Bureau (PWB) has planned, and started constructing, a new additional 50,000,000-gallon storage tank in Powell Butte.

> For our “first look” at this project, CLICK HERE to read that story.
> To see how the City prepared to build Powell Butte Reservoir #2, CLICK HERE.
> See our exclusive story about the project’s groundbreaking last year: CLICK HERE.

“Including the improvements to Powell Butte Nature Park, this is a $137 Million project,” Tim Hall, PWB’s spokesman for the project, told us, as he reintroduced us to the project’s manager and principal engineer, Teresa Elliott.

Looking south across the excavation, no photograph does justice to the immense size of a hole that, late next year, will become Portland’s next water reservoir.

We took the above photo at the project gate, a spot located in the upper right-hand corner of this wide aerial photo that looks to the north above the project. PWB photo

Although the huge excavators had left, and the parade of dump trucks had halted for the season, the Bureau is still at work at on the project, Elliott told us.

“We’re still in the design phase,” Elliott said. “We’re finishing our 90% review; and we’ve submitted our land-use application. We expect the land-use hearing to take place on November 15.”

We asked why the Bureau was allowed to take out 33,000 truckloads of dirt without a land-use permit.

“We have the conditional-use permit for the master plan that says that we can do the work that’s been done,” Elliott explained. “The reservoir is already permitted; it will be the exact size, and in the exact location, as outlined in those permits. The land-use planning to we’re doing now is for elements of the project that have changed since the conditional-use permits were issued – such as changes and improvements to the park.”

> To see our story about recommendations for the Nature Park, see our story: CLICK HERE.

New plans including rearranged the park center, and making the maintenance building look like a farmer’s barn, Elliott specified. “We’ve done some trail plan changes, and altered storm water facilities – minor differences that will improve the overall project.”

Even during the recent sloppy springtime weather, giant excavators filled a never-ending parade of dump trucks with earth dug from the site. PWB photo

A loaded dump truck turns north on SE Division Street from SE 162^nd Avenue, heading toward the Gresham quarry, while an empty truck heads back to the worksite. PWB photo

Big hole to get bigger
Since October, 2009, contractors will have removed 350,000 yd.³ of earth – about 33,000 truckloads worth – Elliott continued, before they finish up this portion of the project in June, 2011.

“We’ve dug the first 20 feet,” Elliott said. “Once the land-use [permits are] finalized, and we have permits for continuing the project, we’ll dig the final 15 feet. We should be ready to resume construction of late spring, 2011.”

Holding off during the winter months is a good idea, she added, because the Bureau’s geology technicians are concerned that the “hopper bottoms” might fill with water. “And, I don’t want a safety risk of somebody falling into a reservoir partially filled with rainwater, after they’ve climbed the fence.”

Digging the “hopper bottoms” – these help water completely drain from the divided tank – will take two or three months. “After that they’ll start pouring concrete and laying out the form work,” said Elliott. “All told, the entire project takes about two years.”

Concurrent with digging and fashioning the reservoir will be installing the plumbing to connect it to Portland’s water system.

This is one of two massive storm water retention ponds (400 feet x 30 feet x 10 feet) built to hold back storm and groundwater from nearby Johnson Creek, so the project will not add to other storm water to worsen flooding. PWB photo

“And along SE 162^nd Avenue, SE Powell Boulevard, and 159^th Avenue, we have three very large vaults that tie into the system, so we can take Powell Butte [Reservoir #1] off-line while we do construction. There will be work that will be concurrent to the reservoir,” Elliott explained.

Many trails will remain open during the construction hiatus, as well as when work begins next spring. “It is import for people using the park that they stay on the trails,” Hall warned. “They’re well-marked. And, be sure to stay out of the fenced construction areas; they are patrolled by police.”

Within a year, this area will be home to a giant water tank buried underground.

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