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Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.


1120 SW Fifth Ave, Suite 600, Portland, OR 97204

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April 5, 2013

While heading north on the I-205 freeway or from SE Powell Boulevard near the freeway ramp, you may have seen construction vehicles at work clearing the south side of Kelly Butte. Crews were busy removing non-native and invasive plants, dead and diseased trees, and unfortunately a few healthy trees.

All of this work is part of the construction of the new 25-million gallon underground drinking water reservoir on the butte.

The plant removal -- through an integrated approach of mechanical cutting and manual removal -- was necessary to build the larger rectangle reservoir that is replacing a 10-million gallon round steel water tank. A temporary wide road for large trucks to haul away excavated soil and carry in concrete and steel had to be built.  In addition, space on the hillside was needed for a new storm water detention pond and overflow holding tank.

While the south slope may now be barren, once the reservoir construction is completed the next phase of the project is a Land Use approved re-vegetation plan that includes planting with more than 1,667 trees and 7,254 shrubs on the entire site. The south side will be replanted with an oak savannah. The north side is where many of the new trees will be planted.  Seeding of ground cover plants like grasses and wildflowers will occur.  The haul road will be reduced in width to accommodate Portland Water Bureau maintenance trucks.

On the west and north side of the butte, the tree canopy that is dominated by Douglas-Fir and Big Leaf Maple trees has been largely left intact.

For over 30 years, invasive plants have degraded the local environment by decreasing botanic diversity and displacing native species, destroying habitat for wildlife and birds, and increasing storm water runoff by decreasing the structural complexity of plant communities.

One of the many vegetation goals for the project is to aid in reducing the level of invasive plants on the butte. With the actions taken, the future landscape will enable the preservation of some upland meadow, prairie and grassy habitats. The project work will also remove invasive plants from the Portland Water Bureau’s property on the butte.

When reservoir construction is complete in 2015, the ground surface above the facility and its pipes will be re-seeded. Re-vegetation services will continue to monitor the new plant life far after the construction is completed.