Water Technology was commissioned to provide specialist services in the areas of flooding and water quality for the proposed 107 lot residential estate located at Jacobs Well in the Gold Coast. The 10 hectare site was subject to significant flood constraints which included regional flooding from the Pimpama and Logan Rivers as well as being located within an overland flowpath associated with an external rural/residential catchment some 60 hectares in area. Flood levels at the site were found to be dominated by storm tide conditions from the Broadwater.
The various sources of flooding that heavily constrained development of the site proved to be challenging in order to achieve a non-worsening outcome having regard to the development layout. A number of iterations were required to the master plan and development footprint for the site in order to reach a suitable development outcome which could be supported and approved by Council. Water Technology were able to define a suitable central drainage channel profile and arrangement to both address Council’s specific requirements as well as providing an acceptable flood outcome for the estate. Earthworks filling scenarios were also assessed in combination with the central drainage arrangements and internal road crossings to achieve suitable flood immunity outcomes for the development having regard to off-site impacts. A combination of 1D and 2D modelling was used for the flood and drainage assessments.
The services provided for the project also included stormwater quality management whereby various Water Sensitive Urban Design features were sized to fit within the proposed master plan. Inclusion of WSUD features as part of the developed also provided challenges given the limited area available within the estate.