Union Bay Natural Area

The Union Bay Natural Area is a public wildlife area, natural restoration laboratory, and an important habitat next to Lake Washington. At 74 acres, with 4 miles of shoreline, it is the second largest natural system left on the lake. Over thirty years of restoration have turned this former landfill into a diverse system of meadows, woods, and wetlands. Considered one of the best bird-watching sites in the city of Seattle, over 200 species of birds have been sighted here.

The Union Bay Natural Area is managed by UW Botanic Gardens to maintain and enhance plants, wildlife and landscape values while serving as an outdoor laboratory for research, teaching and public service. Questions about UBNA should be directed to ubna@u.washington.edu or call 206-543-8616.

Dispatch from a Blue Tube Forest

Restoration in the Union Bay Natural Area
by
Kern Ewing, Environmental Horticulture Faculty
Fred Hoyt, Center for Urban Horticulture Grounds Manager

The Union Bay Natural Area sits atop a portion of what was known for decades as the Montlake dump.  The land for the dump was exposed when the Montlake cut was completed and Lake Washington was dropped eleven feet in 1916.  Filling in of the mud flats with rubbish and other materials began in the 1920’s.  The City of Seattle operated the site as a landfill until it was closed out and graded flat between 1968 and 1970.  The fill surface was seeded with clover and with a non-native grass mixture to prevent erosion and eliminate dust.  Some fruit trees were planted along Wahkiakum Lane, and an occasional pine tree may be found on the site today, dating from this period.

Over the years, various structures were built on the fill in an attempt to realize the promise of turning it into “a usable part of the campus”.  A structure was built at the golf driving range and a clubhouse was built at the old baseball field which was at the corner of 45th Street and the current Mary Gates Boulevard.  Both suffered from foundation cracking caused by unequal settlement of the fill.  Light standards installed on pilings in parking lot E5 (the “dime lot”) showed 4-5 feet of settlement as the lot sank and the pilings did not.  The response to settlement as it occurred over much of the site was to add more fill to level the soil surface.  Because of the ongoing settlement, the University gradually backed away from building any but the lightest of structures on the fill. Continuation of article (page 4)

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