Thinking of subdividing your land?

Any questions? Please call us on

02 9980 1000

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Our team of experienced designers and drafters have a combined total of over 95 years experience in civil design, surveying and drafting fields.

No job too big or small



Our team of experienced design engineers have extensive technical understanding of typical council design guidelines and Ausroad/RMS design standards we incorporate this knowledge into our designs to ensure that all project objectives are met whilst remaining cost effective.


GDS will calculate the peak flow rates prior to commencing the design of main drains and watercourses.


We will then analyse these calculations as a primary consideration when determining the hydraulic grade for your site, ensuring the finished surface level of your developed land is designed to allow for overland water flow through drains and underground pipes.


GDS uses MUSIC Modeling (The Model for Urban Stormwater Improvement Conceptualisation ), a water quality tool which assists the planning and design of stormwater management systems, tailoring  to your land development needs, making sure you achieve water quality targets and requirements for your area.


GDS will accurately assess the performance of stormwater treatment devices and estimate pollutants generated, to provide expert recommendations on the most appropriate stormwater management system for your development.

We output a wide range of high quality detail designs and drawings consisting of:

Storm Water

• MUSIC modelling

• Catchment analysis

• Hydrology and hydraulics

• Stormwater, analysis and network design

• Stormwater management plans

• Water sensitive urban design (WSUD)

• Wetland and detention basin design

• Stormwater Detention/Retention Basin

• Floodway and Channel Design

• Flood and Risk Management Studies

• Stormwater Quality and Quantity Re-modelling

• Hydraulic/ Water Engineering


• Road design

• Intersection design

• Carparks, footpaths, and bicycle paths

• Traffic signs and line marking



• Bulk earthworks

• Erosion and sediment control

• Retaining wall design


Sewage and Water

• Sewer reticulation analysis and design

• Water reticulation analysis and design




• Earthworks, levees, and dams

• Flooding & stormwater modelling (1D & 2D)

• Flood studies

• Hydraulic impact assessments

• Culvert and open channel design

• Pollution Control Schemes

• Erosion and sediment control


Contact details

Suite 3A, 265-271 Pennant Hills Road

Thornleigh NSW 2120


PO Box 498

Pennant Hills NSW 1715

Phone: +61 2 9980 1000