The site is directly adjacent to existing main arterial roads and residential / rural properties and contains steep topography across the site (over 50m in elevation). The site also contains the Ki-It Monger Brook and an existing landfill quarry operation and livestock farming. The geology also comprises significant volumes of clay material and inert landfill. These constraints present many challenges to be overcome in the design and construction phases of the project.

Key Considerations

• Working effectively with the Client, service authorities and other Stakeholders.
• Investigating engineering opportunities and constraints for different planning options.
• Undertaking Remediation of a former use site (earthmoving quarry operations).
• Retention of significant trees and vegetation (with focus on Ki-It Monger Brook).
• Realignment of existing fencing to accommodate livestock movements.
• Providing value adding input into the proposed lot layout.
• Working collaboratively with landscape architect to ensure quality finishes.
• Designing Bulk Earthworks for multi-dwelling sites and single residential lots.
• Upgrade of Chittering Road including drainage modifications and undergrounding of existing power lines.

Project Challenges

Bulk Earthworks

The Bulk Earthworks design requires achieving as close as practicable to a balanced cut to fill and minimising import fill whilst maintaining functional design grades through the 50m elevation. This was complicated by the technical nature of the site, level differences across the sites and Client request to focus on minimising extent of retaining walls.

Geotechnical

The existing site geology is constrained by significant volumes of clay in the elevated areas to the east and also deposits of inert landfill within the quarry operation site. JDSi is working closely with the geotechnical engineers and planners to ensure these materials are engineered to maximise development yield whilst minimising remediation costs and without compromising structural integrity and quality of work.

Stormwater Solution

JDSi successfully negotiated the stormwater drainage strategy outfall solution with the project hydrologist and local authority. This includes capturing the minor stormwater events within the public open space areas, with major events being conveyed into the existing Ki-It Monger Brook whilst still creating a useable space for the public to interact with.

Overhead Powerlines

JDSi has split the electrical works into separate works packages to ensure existing distribution and consumer mains along Chittering Road are converted to underground, and the overhead powerlines could be removed by Western Power prior to the commencement of the Bulk Earthworks.

Contract Management

JDSi integrated multiple works packages as separable portions within a single contract to achieve the Client’s requirements. This arrangement will have the added benefit of a single contractor completing the works which encompass earthworks, civil works and potentially landscaping disciplines mitigating interface issues whilst delivering a high quality of work in a shorter duration.

Road Upgrades

Working with service and local authority to design suitable upgrades of Chittering Road and Great Northern Highway to cater for interim and ultimate (Directions 2031) development requirements whilst considering and maintaining a strong and aesthetically pleasing interface for the development estate.