ABOVE: Workers installing new stepping stones across the stream in early September. (Photo courtesy UW Botanic Gardens)
The major construction component of the Rhododendron Glen stream restoration project is almost complete. The contractors, Forma and Terra Dynamics, used heavy machinery to remove the old stone “dam” at the upper pond, and to excavate and regrade the pond and stream channel. They installed new cobblestones, in various particle sizes, along the pond and stream bed, as well as large woody debris, to prevent erosion and enhance the stream’s natural character and habitat value.
“Right now, the contractors are putting down more soil, including a special, well-draining mix that’s ideal for rhododendrons and was developed by the Rhododendron Species Botanical Garden,” says UW Botanic Gardens Curator and Associate Director Ray Larson. “They are also finishing installation of the new irrigation system—putting in sprinkler heads and adjusting to finish grades.”
“They will soon be doing final work on the pathways, including the new accessible pathway connecting the new seating/overlook area to the Centennial Garden. The main outlines of the seating area are in place, with the larger rock work on the west side completed. The benches will be installed last, hopefully in the first two weeks of November.”
BEFORE: The overgrown and heavily silted upper pond, with dam intact, prior to restoration.
AFTER: Restoration included widening the stream bed; removing weeds and silt; and installing new cobble.
Downslope from the new seating area, the contractors created a new, wide planting bed alongside the lower course of the stream as it exits the Glen and enters the Azalea Way Pond. They also installed a series of the large stepping stones connecting the grassy slope of the lower Glen to the Centennial Garden.
“As soon as the fences come down in another week or so, we will begin planting trees, and doing some more intensive planting work along the upper restored creek area,” says Ray. “In general, shrub and perennial plantings will occur over the next few months.”
See our August blog post for details on the new plants coming to the restored stream section of Rhododendron Glen.
In early September, a very special visitor—Mary Ellen Mulder—came to tour the work site and see all the wonderful progress the Arboretum partners have been making in Rhododendron Glen. It was a catalytic gift from Mary Ellen and her husband Gordon, who sadly passed away in April of this year, that made the restoration of this iconic garden possible.
More project details: Visit our “Revitalizing the Arboretum” page.
New cobble and large woody debris in the stream bed will prevent erosion and create aquatic habitat.
Construction of the new seating area/overlook in the lower Glen area is nearly complete.
Mary Ellen Mulder (second from right) touring the project site in late summer.
Project map, courtesy Berger Partnership.