Contact Us

02 9980 1000


Suite 3A, 265-271 Pennant Hills Road Thornleigh NSW 2120

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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.

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


  • 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

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


  • 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

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.

Group Development Services uses MUSIC (The Model for Urban Stormwater Improvement Conceptualiation ) to assist the planning and design of stormwater management, tailoring to your land development needs, ensuring you achieve water quality targets and requirements for your area.

No project is too big or small, we can simulate stormwater detention and flow from a single lot to a whole suburb.

Stormwater management

Group Development Services can manage your storm water capabilities and create water sensitive urban designs (WSUD) and integrated water-cycle management (IWCM) using MUSIC to identify the best way to firstly capture and remove contaminants and then reuse storm water runoff.

Using tanks, rain gardens, swales, bioretention and/or buffer systems, (to name a few) GDS will choose the stormwater storage system to suit your needs and complying with standards set for storm water volume and pollutants.

We will plan your entire storm water system, giving you the optimal design and receiving-water quality as well as estimate the impacts of various treatment options to give you optimal water-quantity and quality and ensuring the best cost versus benefits solutions.