Kotuitui Whitinga Footbridge

Completed 2014

Harris Butt Architecture in association with GHK Piling and Richardson Stevens Consulting submitted their entry along with four other consultant groups for the Waiarohia Stream Footbridge Competition. This design by local architects, contractors and engineers was selected as the winning entry over the entries of some larger Auckland based construction companies. The competition required a design solution for an opening footbridge across the Waiarohia Stream. The aesthetic and design intent were critical aspects of the WDC assessment criteria for each submission. This wining entry for the Waiarohia Stream Footbridge completes a new cycle and walking loop that joins the Town Basin Marina to the new Lower Hatea River Crossing.

The simple form of the bridge is a derivative of thoughts based around movement, journey, water, light, food gathering and cultivation with connection to historic and current occupation of the place. All establishing and reinforcing “a sense of place.” The bridge in its most simple form is seen as a link. Out of this comes the potential for many implied metaphors, which create the opportunity for all who see and use the bridge to make their own connections and interpretations. The bridge meets the need to cross the stream in a safe way whilst allowing for the occasional passage of boats up and down the stream.
Nine main bridge piles, which support a sloping column/mast structure, are placed at approx 10m centres. The main variation to this occurs at the opening section of the bridge. The mast supports the screen and handrail to the upstream side of the bridge and also the lighting units. Cantilevered beams are attached to the column/mast as main supports for the bridge deck. This column/mast structure is reminiscent of the traditional Maori ko or digging stick with the teka, or tread attached. It also references the lightweight structures erected for the catching of Inanga or Whitebait).
white-bait-structure
The two screens are fabricated as panels, which are then simply attached to the vertical. On the down stream side, these panels are framed sections of woven mesh (a “net”) whilst the upstream screen is fabricated out of “distorted” bar. This bar alternates in height with the low portion of the screen being at 1.4m high off the bridge surface, the higher portion ranging between approx 2.0m and 4.0m (the form of the screen referencing the coastal vegetation and surrounding land forms).
The bridge deck is made from precast concrete panels with a textured/exposed aggregate finish. Where the panels are connected to the main cantilevered beam supports, stitch joins occur which are expressed to reinforce the sense of journey and acknowledge the subtle change in direction and pitch as appropriate. The pattern on the bridge deck was derived from the weaving patterns of kete. Kete often incorporated metaphoric symbols related to food, land formations, elements etc. In this case consideration was given to the idea of the flow Inanga swimming up stream.
kete-image
The bridge has a low, horizontal profile, which is not affected by the opening of the centre section. Subsequently a minimal, elegant structure has been created which appears to simply ‘float’ across the stream. The moving section of the bridge is opened/rotated using a hydraulically operated ram. This component is seen as a distinctive “switch” both separating and connecting Hihiaua and Okara. The design was driven by the desire to remove any extraneous items from the bridge. For example, the lighting is an integral part of the masts with the masts supporting the screen with the screen rails acting as conduit for power. This approach allowed for the ability to prefabricate the majority of the components thereby minimising on site fabrication. This greatly reduced the risk of pollution and damage to the surrounding eco-system. The new bridge has now become an iconic feature of the Whangarei City from the Hihiaua Peninsula to Port Road across the Waiarohia Stream.