Snøhetta has unveiled its new transformation plans for a 150-year inaccessible industrial region of North America - Willamette Falls - to revive the area with new river walks and public spaces overlooking Oregon City's waterfront. Willamette Falls is the second largest waterfall by volume in North America, but the region has been inaccessible to public for 150 years. 

Snøhetta will design new public spaces on this industrial region that will allow visitors to rediscover the full height of the falls and its rugged shoreline, uncovering swaths of the 22-acre site’s historic basalt topography and reconnecting Oregon City to its spectacular waterfront. Snøhetta's design will be developed as a complex two-year design process, underpinned by a significant public engagement effort that has reached thousands of unique participants.

The above image shows the transformation of The Woolen Mill, which will serve as the public terminus of Main Street, offering 360° views of PGE dam, the historic boiler complex, the restored river alcove and The Public Yard. Through selective removal of existing structures and platforms, the full height of PGE dam is revealed and the historic boiler plant complex becomes a defining focal point of the riverwalk. An elevated explorer trail connects the yard area to the boiler plant complex, providing interpretive opportunities focused on the restored alcove habitat and the historic Woolen Mill Foundation. 

Willamette Falls Riverwalk. Image © Snøhetta 

"The riverwalk will serve as a portal to the Northwest’s collective history, reviving a former industrial site through its aggregated layers of natural, ecological, cultural, and geological history. Beginning at the entrance to Oregon City’s historic downtown and ending at the crest of the falls themselves, the riverwalk is conceived as sequence of islands, an archipelago carved from ancient basalt and industrial steel, concrete, and wood alike," said Snøhetta.

"The new design treats the whole site as a single landscape, with a network of promenades and lofted pathways that lace through the physical strata of the site, immersing visitors in a tactile experience that celebrates the changing water level, the feeling of the spray on your skin, the dramatic play of light and the roar and presence of the falls," added the studio.

Snøhetta divides the design of the region into four segments called North Riverfront, South Riverfront, PGE Dam and Mill E and Canemah. The site encompasses the location of Oregon City’s historic downtown. Over time, industry boomed and overtook the shoreline, and for the past century, the waterfront has been completely inaccessible to the public.

Willamette Falls Riverwalk. Image © Snøhetta 

In the first segment of the area, the studio transforms the Woolen Mill Alcove with a Public Yard. Today’s industrialized river edge diminishes the ecological value of the shoreline. The riverwalk design carves away industrial fill and structural platforms to restore region-specific ecosystems, such as alcove and riparian basalt habitats. 

Proposed inlets and exposed rock outcroppings provide critical off-channel moments for migratory salmon and other fish species to rest before they undertake their passage upstream beyond the falls. This particular alcove reveals the Woolen Mill’s historic relationship to the river and source of water power. To support public access, the walls of the pipe chase are selectively removed, leaving behind lower portions of the structure re- used as a porch-like promenade at the water’s edge. 

Removing structure lessens shadowing impacts on river ecosystems, while retained remnants of the structure enrich historical interpretation of the water’s edge, allowing people to mentally reconstruct what once occurred on the site.

Willamette Falls Riverwalk. Image © Snøhetta 

The Mill O Visitor Center and Pipe Chase Porch will be visible from Main Street and commanding a presence from the water, Mill O, the historic extension to the Oregon City Woolen Mill, is well- positioned to serve as the riverwalk’s visitor center. The exterior shell of the building is reinforced and retained, while the interior is opened up to make a large public hall, and offer opportunities to re-use interior wood structure. 

Large portions of the ground floor spill out to the adjacent public yard, creating flexibility and all-weather use. The eastern end of the structure is conditioned and provides restrooms, a kitchen, storage, and flexible use spaces. It also supports upper stories of the building devoted to redevelopment.

Willamette Falls Riverwalk. Image © Snøhetta 

To offer prominent views of the falls and river valley to the south, the industrial corrugated cladding of the existing Mill H structure is peeled away. The structure is opened to light and air while revealing the reinforced steel and concrete structure of the mill. Portions of the Mill H ceiling are carved to further open the space connecting the interior to the sky. 

The concrete foundation of Mill H is repurposed to hold conifer tree species, referencing the historic wood- based paper-making processes that once took place in the structure. Upper levels of the structure provide falls viewing vantage points, while the lower levels draw visitors to The Clarifier path and the Hawley Powerhouse Station Falls Overlook beyond. 

The Mill H aspects of this view - the grove, the overlook, and improvements to the structure, are planned to be included as part of Phase I of the riverwalk. Key Plan a large volume of soil to support a grove of native conifer tree species, referencing the historic wood- based paper-making processes that once took place in the structure. 

Willamette Falls Riverwalk. Image © Snøhetta 

For the clarifier landscape and PGE Dam Promenade, Snøhetta proposed walkway rings the clarifier, a water quality treatment structure once used by Blue Heron Paper to treat waste water from its paper making processes. The landscape interior of the clarifier is inspired by the region’s oak savanna habitat featuring characteristic Oregon oak and camas plantings as well as basalt salvaged from the site. 

Families can gather, picnic, or rest in the landscape with expansive views to the river and West Linn Paper. The clarifier pathway links Mill H to the falls overlook, allowing full public access to the falls when the PGE dam promenade is closed for operations and maintenance. 

"Collectively, the riverwalk sequence opens a new chapter in the life of the site, one that reimagines Willamette Falls in its fullest, most expansive depth in nature, culture, and time," added the studio.

Construction for the structures is expected to begin in June 2018. New public gathering space is conceived to anchor the site as a civic heart of downtown, offering key opportunities for events and redevelopment that will drive economic renewal. The design will also provide greater access to the five confederated tribes who will continue to annually fish the waters as they have done since time immemorial.

Top image: Willamette Falls Riverwalk. Image © Snøhetta 

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