Aoyuan International is developing the 125Ha master planned Coomungie & Chelsea Gardens residential community located at Moss Vale in the Southern Highlands of NSW. When completed, will supply up to an additional 1,200 homes to the district with lot sizes ranging from 450sqm to 2,000sqm. The master planned development will take up to ten years to be developed, with the first stage being circa 176 lots. This project seeks to balance a mix of lot typologies in keeping with the character of the place and the existing natural landform. More than 20 per cent of the site will be dedicated to green open spaces, lakes and recreational facilities.

Orion Consulting was engaged by Aoyuan to review the concept engineering and prepare civil design documentation for Stage 1 of the proposed development. As part of the engineering review, Orion Consulting assessed not just Stage 1, but looked at the key engineering aspects of the site as a whole, including the development of strategies for site wide bulk earthworks and integrated water cycle management.

One of the core development objectives was the need to minimise the impact of the project on the surrounding community; with a focus on minimising external truck movements and rationalising the site contouring to effectively use the existing undulating landform. This collaborative approach to achieving social and environmental outcomes was fundamental in the development of a balanced earthworks model, that sat alongside a flooding and stormwater quality management strategy, that in turn worked in harmony with the open space strategy and vision provided by Arterra Design.

Orion Consulting worked in conjunction with Aoyuan and Arterra Design to come up with an urban form and engineering outcome that respected the landform and the local community. Stormwater and earthworks options were tested and as a result it was possible to achieve a reduction in import of 100,000 cubic metres of fill in Stage 1 alone. This coordinated design approach was projected across the whole site layout, which led to a rationalisation of the water management strategy to optimise the earthworks and enhance the open space vision.

By undertaking these design development and coordination exercises early in the project lifecycle, Orion Consulting was able to significantly minimise earthworks quantities, simplify and rationalise the water management strategy which will allow for easier long-term maintenance and provide greater areas for open space, as well as highlighting key project risks and opportunities for further consideration. This is a great demonstration of how the engineering design can be used to enhance the key client drivers for project success.

Civil Design – Roads and Drainage

Civil Design – Site wide masterplan Bulk Earthworks and site regrading

Civil Design – Site wide Integrated Water Cycle Management

Project Management and Coordination

James McLeod, Chris Scholes, Raul Cid