by Tim Hall

Portland Water Bureau

Making way for a better Kelly Butte landscape

 

During first three months of the year, construction vehicles were at work clearing a large section of Kelly Butte. Crews were busy removing non-native and invasive plants, dead and diseased trees, and unfortunately, a few healthy tree as well.  All of this work is part of the construction of the city’s new 25-million gallon underground drinking water reservoir on the butte. Kelly Butte is north of Powell Blvd. and east of I 205.

For over 30 years, invasive plants have degraded the local environment on Kelly Butte by decreasing botanic diversity, displacing native species, destroying habitat for wildlife and birds, and increasing storm water runoff by decreasing the 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 Portland Water Bureau’s section of the butte.

Some plant removal was necessary to build the larger rectangle concrete 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 as well. In addition, space on the hillside is 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 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 smaller maintenance trucks.

When the reservoir construction is complete in 2015, the ground surface above the facility and its pipes will be re-seeded. 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.

With the actions taken for the project, the future landscape of Kelly Butte will enable the preservation of some upland meadow, prairie and grassy habitats. Re-vegetation services will continue to monitor the new plant life far after the reservoir construction is completed.