Sydney Harbour eyesore rejuvenated to reflect its wooded headland, colonial estate, refinery past

But on Saturday July11, the thoroughly rejuvenated site, was officially opened by NSW Premier Nathan Rees.
Originally a natural, wooded headland occupied by Aborigines, it formed part of a 550ac (223ha) colonial land grant to William Balmain and encompassed most of the Balmain peninsula. The current site was subsequently sold to John Gilchrist and the boundaries reflect this delineation today.
From the earliest days of European shipping in Port Jackson, its landscape was altered as visiting ships, having unloaded their cargo, hewed sandstone from the site, taking it as ballast for their return journeys. Thus the site earned both its English name and the steep cutaway that defines its southern side.
In 1864 Thomas Perkins built a maritime villa Menevia on the site. It lasted for 66 years but was demolished in 1930 following the Texas Oil Company’s purchase of the site in 1928. Caltex occupied the site for another 74 years until 2002, processing and storing oil-related products. Reminders of tank rings and part of the bund wall in the northern part of the park, give a clue to the scale of this industrial activity.
Ironically, the start of Ballast Point’s journey back to a green headland, began at the very time that it was being converted for industrial use, when the Lang Government acted to preserve Balls Head, immediately across from Ballast Point, in 1926.
It was this seemingly unrelated event that would ultimately prove critical in the decision of another Labor Premier, Bob Carr, to acquire Ballast Point for public space in 2002. The public value of Ballast Point as a 2.6ha green space lies not just in its own significance, but in the relationship it now forms with Balls Head, as the green gateway to the Parramatta River a mile up Sydney Harbour from the Harbour Bridge.
Overview
Landscape architects McGregor & Coxall, used cutting edge environmentally based design strategies, in the reconstruction of this degraded site. The design reconciles the layers of history, with forward looking new technologies, to create a regionally significant urban park. The environmental approach is achieved by site-wide storm water bio-filtration, extensive and innovative use of recycled materials, the use of locally collected seeds to re-plant the site and wind turbines for power.
Construction excellence
The steeply sloped site included sheer cliff faces, whilst exposed and latent heritage items and poor road access through narrow streets, provided a complex web of construction, safety and environmental challenges.
Landscape Solutions and McGregor’s design team, could only undertake geotechnical investigations after possession. So the subsequent discovery of latent conditions, forced significant adjustments and on the run redesign of levels, requiring close collaboration between contractor, superintendent and client.
An innovative product was required to terrace the site. The concept from the architect was for a reinforced earth wall with custom gabion face, and this was engineered by Landscape Solutions.
The final design was a unique wall that had never been built before and required some innovative thought and commitments from the construction team, including the reuse of re-engineered site fill, screening and mixing on site of specific sized and coloured recycled aggregate for the gabion infill, and intricate construction sequencing. Due to the site’s topography, temporary access platforms for heavy equipment were built and pulled down regularly.
The site has a significant heritage feature in the middle of the site, the former building, lying in the middle of the main (and only possible) construction access road. This created significant access constraints, and an archaeologist was engaged by Landscape Solutions to assist in the excavation and management of construction activities required through the area. The result is the preservation and magnificent display of the foundations of the original Menevia.
Innovation
Examples of post occupation innovation were: redesigning the amphitheatre area to accommodate revised site conditions and reducing costs, screening existing site material to create engineered fill for behind the gabion walls and the use of existing structures and hidden features previously unknown.
The curved faces of the reinforced earth wall and non standard gabion baskets meant each panel was individually made to suit the curve of the wall.
The implementation of existing structures into the project required the LS team to be flexible and to work closely with the design team. The removal of lead based paint on tanks, and the reuse of existing walls and structures, was both technically difficult and evolutionary.
The use of Italian wind turbines within the conserved Lube Ring, to feed power back into the grid to offset the power used on site for lighting, had not been done in Australia before and added a new degree of technical expertise. In particular, they used a battery bank to trickle feed the grid
Technical complexity
Technical complexities of the project included:
Earth Reinforced Walls with custom gabion style faces. The 300mm face basket had a 23 angle. This in combination with curved corners and compaction over the reinforcement in 600mm layers, required innovative solutions. Compacting so close to the gabion and at an angle, required a high degree of handwork; large equipment was not capable of the compaction required on the inside invert. With walls more than 20m long and up to 9m in height, the difficulty was in maintaining a plum rear face whilst the angle of the front face stayed in alignment around stairs, and to allow the fitting of predetermined curved, precast caps. Extensive trial and error fine tuned their successful construction.
Cutting gateways through existing concrete bund walls and concrete retaining walls, is certainly not an everyday occurrence for any contractor, and Landscape Solutions needed to complete two of these on site.
The first gateway was created by cutting through the heritage bund, with the cut piece then used to create the walkway through the wall. A wall mounted track saw was used to cut the opening and an 80t crane lifted the piece after two holes were cored for lifting points. All this occurred under the watchful eye of structural engineer focussed on the wall’s continued integrity.
The second gateway was created to accommodate southern stairs. This was to be cut though the existing hardstand area, with no geotechnical knowledge of what lay beneath. Landscape Solutions discovered structural beams that extended from the rear of the wall and through various fill material. The result is an innovative use of the beams to create a feature as visitors walk down the stairs behind the original wall on the cliff, and then down the southern stairs.
Environmental constraints
Sediment control was the major concern dealing with such a sloped site. This required extensive terracing using large equipment and in many cases occurred close to the waters edge. Landscape Solutions’ target was for absolutely no sediment in the harbour.
Sediment fences were installed at all perimeters and throughout the project. Diversion and earth mounds were installed to pool water wherever possible. All sediment controls were rigorously checked daily using our site specific checklist. During heavy rain they were checked every few hours and cleaned regularly.
The external boundaries of the site were soft landscaped as early as possible with turf, a wetland and gardens to create a natural sediment trap and reduce dust. A sediment control fence on the harbour’s edge was a “last resort”, and was never breached throughout the 18 month program.
Resource recycling/reuse
Not only was no material taken off the site, but certain elements which had been removed during earlier remediation, were reclaimed and reinstated.
Re-use of materials sourced on site, such as site soil, crushed concrete, sandstone boulders, general fill material and suitable mulched vegetation.
All rubble was recycled and used in the gabion baskets. As well, various recycling plants around Sydney contributed bricks, concrete and steel reinforcement. For added interest, recycled artefacts to represent past uses of the site were placed randomly in gabion baskets.
The engineered fill behind the Gabions was ameliorated and re-engineered site material, with oversize rock crushed and reused for landscape fill.
The site had numerous steel tanks previously used by Caltex. One of these, Tank 101, was cut up and used to build large letters which appear as Les Murray poetry on The Lube Ring structure.
Soil under turf was recycled from an off site source and no VENM was used in gardens or turf areas. The concrete used throughout the project was an EC1 Green mix, a recycled concrete that provide challenges due to its shot blasted finish and structural strength.
All stormwater collected on site, is treated through a series of wetlands, on the northern and southern faces. Planted with ephemerals, the one on the northern promenade, features filtered water spouting through one of the gabion walls over natural rock.
Throughout the site there is extensive reuse of on site materials such as pathways, roadways, old tanks, bund walls, existing concrete, all these required a high degree of co-operation with the Architect and Landscape Solutions. These are just a few of the items that demonstrate the working relationship that all parties had to achieve such an innovative project.

Official Opening

"Sydney Harbour Foreshore Authority is delighted with Ballast Point Park. The site's transformation from a former industrial wasteland into a benchmark community park was only made possible through quality design and world class construction."
Di Talty, Executive Director Strategic Projects