Causeway Pedestrian and Cyclist Bridges

The design of the bridge resulted from consultation with key stakeholders including local governments, Traditional Owners, specialist groups, cycling and boating authorities and other government agencies, taking into consideration path user requirements, local developments on either side of the bridges, future maritime height allowances and the needs of existing river users.

Built as two bridges that connect over Heirisson Island, the s-shaped curves of the bridge’s design represents the sinuous movement of the Wagyl (rainbow serpent), while supporting the increased clearance heights above the river and minimising the number of trees impacted by construction.

Key to this design is minimising impacts to the sacred Swan River (Derbarl Yerrigan). The cable-stay design ensures less impact to the river, with only three permanent piers required to support both bridges.

The location, approximately 90 metres downstream of the existing Causeway traffic bridge, was chosen as it minimises impacts on flora and fauna, while improving path user connections and amenity.

Integral to the design are references to prominent Whadjuk Noongar people, including: Yagan, a warrior and young leader, represented by a boomerang-inspired pier, and Balbuk who fought to retain the Swan-Coastal Plain’s over-development and is represented by two digging stick-inspired piers.

The bridges have been designed to cater for navigational clearance and future sea level rises. The new bridge on the Point Fraser side will have 6.2 metres of navigational clearance, while the new bridge on the McCallum Park side will have 5.1 metres of navigational clearance, allowing for smooth passage of marine vessels.

The bridge design is curved to minimise the impact on existing trees, to assist in accommodating the height requirements of the navigation channel and to slow down cyclists traveling downhill when approaching key intersection points.

The design has been extensively workshopped with key stakeholders, and the State Design Review Panel supports the elegant, curved form of the bridge structures, which blend into the natural environment.

Two of the three piers are inspired by the shape of wannas, or digging sticks. A traditional wanna is shaped with one round end, and one slightly flattened end, hence the piers are different at the top to depict each end of the wanna. The wanna is a tool used for harvesting edible roots, particularly the yangeti, which grew around Matagarup and the wetlands and lakes. The wannas symbolise Balbuk, a woman who fought to maintain her rights to Country in the face of development.“When a house was built in the way, she broke its fence-palings with her wanna and charged up the steps and through the rooms…”

One of the three piers is inspired by the shape of the dowak, the killer boomerang. This is a tool used for hunting game, and is thrown hard and low to the ground. The dowak symbolises Yagan, a strong, young Whadjuk warrior, who was one of the leaders in resisting colonisation from 1829, until he was killed in 1833.

The MEG have requested that Yagan’s statue, currently located on the southern end of Heirisson Island, be relocated to a more prominent position within the vicinity of the new pedestrian and cyclist bridges. The statue holds great symbolism and value to the Noongar community; not only for what Yagan stood for as a person, but also because of the recent history, where a repatriation mission was successful in the return of Yagan’s head from the British government in 1997, where it had been since 1833. We are investigating options to relocate Yagan’s statue to a more prominent location within the project area.

The new bridges will cross Heirisson Island, providing an opportunity to highlight the important role the Island had in Perth’s Noongar heritage. This project will provide improved connection for both pedestrians and cyclists to the river and foreshore area on the island, while enhancing the natural environment through landscaping and showcasing Whadjuk Noongar heritage. It is anticipated that this will result in activation of the island, welcoming visitors and locals alike.

The existing Causeway traffic bridge is heritage listed and will not be modified as part of this project. The current path will remain and path users will continue to have access, both during construction and once the new bridges are open.

The bridges will be fabricated steel decks made from weathering steel, which provides a “rusty” appearance, with no painting required. Construction will start from McCallum Park, and work towards Heirisson Island, and then onto Point Fraser. The bridges will be split into segments of up to 40 metres in length, which will be installed via a combination of a large land-based crawler crane and a barge for segments that are outside of the crane’s reach. The pylons, which are up to 50 metres in height, will be installed via the crawler crane.

Construction on land will involve ground preparation, piling (setting deep foundations for bridge abutments) and earthworks for the bridge approach embankments.

In-river works will include piling, pile caps and constructing pylon structures. The two ‘lay down areas’ will be at the Point Fraser and McCallum Park foreshores near to where the bridge lands.

Works will be conducted to minimise any impact to community, foreshore park users and river vessels. Advanced notice of impacts will be provided on the project website and to those directly affected.