Design options for the pipe chase

Wed 4 Jan 17

At the riverwalk design community event held on November 17, we shared design options for the pipe chase area of the site (reference Area 2, South Riverfront on the map below).  A few discussion topics at the heart of these design options include:

Access. Re-use of the pipe chase structure can provide an easy connection to the southern portion of the site. Removal of the structure will require access to the falls through the interior of the site, away from the river or through constructing new access routes.

Healthy Habitat. Removal or partial removal of the pipe chase will provide healthy habitat and protect water quality. Opportunities exist to expand alcove habitat, which supports salmon, steelhead and pacific lamprey.

Views. Along its length, the pipe chase can provide views of the falls to the south, the river to the west, and views into the interior of the site to the east. If the lower level is utilized, safe proximity to the river can be supported. Retaining the pipe chase could potentially block views from the yard area to the river.
At the event, five ideas were presented:

1.  Use the pipe chase as a porch, with covered gathering space and pedestrian connectivity on the upper deck. Habitat enhancements could occur behind the structure, but would limit connectivity to the river.


2.  Convert the pipe chase into a deck by deconstructing the bottom of the structure, allowing riparian habitat connectivity to the upland parts of the site.


3.  This idea is a hybrid between the first two options. It includes a smaller covered gathering space with a top and bottom deck. The bottom deck has penetrations to allow light through to benefit riparian habitat and fish.


4.  Retain a smaller portion of the pipe chase and connect habitat areas on either side. This would be an opportunity to create a destination accessed by explorer trails.


5.  Remove the pipe chase, almost in entirety, for the benefit of ecological connections. A small portal remains as another variation of a covered gathering area and viewpoint to the Willamette River.


As we move forward in design, these options can be combined, modified and hybridized to craft the preferred riverwalk design. Our design team will consider community feedback along with technical information such as flood impacts and structural integrity. The feedback received at the event and on the online survey showed a high level of support for the porch option and the porous option, in which covered areas are provided for viewing.

Other input included:

  • Views are important. A pipe chase element should include broad views, perhaps to both sides. There was also concern that the pipe chase would block views from public yard.
  • There were many suggestions for design tweaks, such as views to the river from the floor, leaving some portions open to sky, keeping portions completely closed in, planting vegetation on top, etc. Many expressed the desire for some protection from sun and rain to increase seasonal usage.
  • There was concern about the safety and security of the pipe chase, particularly at night.
  • There were suggestions for interpretive information and/or having an area for cultural presentations.
  • There was support for habitat restoration and also walking through habitat areas to get to the pipe chase. There is a desire for continuous/looping trails.

For full results of the survey and event workshop, see the report here.

Take our online design survey here.

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