Here’s your chance to look into this new outer East Portland Water Bureau project, which they say will benefit all water users in the area …
High atop Kelly Butte in outer East Portland, work crews set rebar for the concrete encasement in which the reservoir’s inlet/outlet pipes will be embedded.
Story and photos by David F. Ashton
Last month, a large group of protesters gathered under the Mt. Tabor Reservoirs, saying that the City of Portland doesn’t need new reservoirs – that the open, century-old landmark water ponds work just fine.
> See the story about the July 12 protests at Mt. Tabor Park: CLICK HERE.
Portland Water Bureau Kelly Butte Reservoir Construction Manager Thomas Gilman stands next to one of the 48-inch-diameter mortar-coated steel pipes before it is encased, giving you a sense of scale for these water conduits.
But, on a trip to survey the progress being made on the new Kelly Butte Reservoir, Portland Water Bureau (PWB) Public Information Manager Tim Hall said that building new reservoirs – including the Powell Butte Reservoir No. 2 – is necessary to provide customers with enough water storage to meet future demands.
“During hot summer months, we can have as much as 200,000,000 gallons a day go through our system,” Hall told East Portland News at the Kelly Butte Reservoir work site, located just east of I-205 and north of SE Powell Boulevard.
This pipe, to carry water out of the east tank of the Kelly Butte Reservoir, is about to be encased in high-strength concrete, providing additional seismic durability.
“With the pending disconnection of the 75,000,000 gallon Mt. Tabor reservoir, and of the 50,000,000 gallon Washington Park facility, these new reservoirs will provide the water storage that will be lost,” Hall added.
When asked why the PWB was about to decommission two “perfectly good” reservoirs – part of Portland’s heritage – Hall said there were two reasons.
“The first is that the Environmental Protection Agency has set up new rules that prohibit open drinking-water reservoirs. They want municipalities to have the safety and security of enclosed facilities. Portland is one of very few cities that still operates open drinking water reservoirs. Other municipalities began to cover or bury their facilities in the 1970s.”
Once the reservoir is built on top of it, this is the pipe in which water will flow into the eastern tank.
As for the second reason, Hall reminded that Portland is in an active seismic area. “The reservoirs being decommissioned were built at the turn of the century. There is very little rebar – something that’s standard in all of our newer projects, but which wasn’t standard back in the late 1800s. Today, the standards of construction are designed to meet seismic standards.
“One of the concerns is always been whether or not the Mt. Tabor reservoirs would remain intact during a moderate earthquake,” Hall added. “Working reservoirs are one of the City’s ‘best hopes’ of fighting the fires that would break out in an earthquake or in another natural disaster.”
This is the last time these four heavy-duty pipes will be seen — just before being encased and buried. The pipe closest in the photo, “necked down” to a smaller diameter, will be an inlet to the east cell. The others are an inlet to the west cell, and the outlet pipes that will be connected to the hopper-bottom of each cell.
While jouncing up the hillside in his vehicle at the construction site in mid-July, PWB Kelly Butte Reservoir Construction Manager Thomas Gilman said they began construction in November, 2012.
“That’s when we started demolition of the old 10,000,000-gallon steel aboveground tank, in preparation to construct a new 25,000,000-gallon buried concrete reservoir,” Gilman explained.
Now, during the summer of 2013, the contractors are doing some excavation, and installing inlet and outlet pipes that run under the hopper-bottomed reservoir, Gilman said.
The facility’s North Valve Vault is where the flow of water will be remotely-controlled, once the reservoir is built.
“Kelly Butte is a strategic location,” Gilman said. “Its elevation is just below that of Powell Butte, but higher than the Mt. Tabor Reservoirs. This tank will serve not only east Portland, it will also supply water all the way across into southwest Portland. Basically, all the Portland Water Bureau customers get fed out of this site.”
Like the Powell Butte reservoirs, the Kelly Butte tank is a divided water storage facility, with two individual “cells”, each with a capacity of 12.5 million gallons.
This is the foundation for the “Parkrose Meter Vault” that measures the outflow of water flowing into the “Parkrose Water Main” – the sealed pipe sticking up from the ground, the background.
Building a reservoir starts with laying pipe – in this case, really big mortar-coated steel pipe, 48 inches in diameter. “A Certified Welding Inspector observes the welding of all of the seams, and examines the joints,” Gilman said. “They also do an air-pressure test to make sure they don’t leak.”
Unlike the City’s 100-year-old reservoirs, where the pipes were laid in on a bed of gravel and buried, all of the water pipes in and out of the Kelly Butte facility are encased in concrete, Gilman pointed out. “This is critical to the infrastructure, to keep water flowing. It helps provide seismic stability and supports the pipe against any settlement that might occur.
Before long, the Kelly Butte Reservoir structure will rise at this location.
Hall said the Kelly Butte Reservoir is expected to come online in 2015.
“While we understand that there are some people who are not happy with the decision to disconnect the open reservoirs,” Hall said at the end of the tour, “we hope that folks will understand that for water quality, for security, and for safety reasons, we have made the decision to disconnect the reservoirs and build these new facilities.”
© 2013 David F. Ashton ~ East Portland News