Many Local Government Authorities (LGA’s) are now requesting concepts designs to be provided in the Development Approval submission.

Since the adoption of the Building Act and use of Private Certifiers, LGS’s have developed more specific Planning Guidelines to ensure that the Certificate of Design Compliance (CDC’s) take into account any adverse site or servicing condition that could affect a proposed development.

Regional and specific site conditions, such as soil types and a high ground water table, can pose significant restrictions on system designs and spatial requirements. An simple example would be stormwater drainage in areas where a high ground water table or a low porosity soil exist that could result in complex and large areas being required to accommodate swales or drainage basins.

Some LGA’s have aged drainage networks that have limitations on volumes and flows that can be accommodated from developments. The result is that on site detention systems must be designed to ensure the development does not impact on drainage networks.

Multiple or Group Residential and Commercial developments in un-sewered areas could fall under the jurisdiction of the Perth Metropolitan Sewerage Policy. Establishing if a project needs to be connected to sewer would be of primary importance when assessing the viability of a project. The Sewerage Policy is overseen by the Health Department of WA.

LGA’s cannot advise developers on Policy compliance. The Health Department are usually not contacted until “Design for Building Approval” is commenced. Without early assessment the Developer could incur costs for the extensions or modifications to the existing sewer network and/ or the provision of a Private Pumping Station to comply with the Policy.

Another issue is the adequacy or other wise of Reticulated Water Mains to provide compliant fire service flows and pressures to satisfy AS 2419 and AS 2118 as applicable. Having the Water Mains tested and the results reviewed by Hydraulic Services Consultant can provide developers with information as the need for fire tanks and pumps.

By engaging a Hydraulic Services Consultant to prepare Design Concepts and Feasibility Reports , the Developer can be assured the unknown aspects are addressed, resulting and can make informed decisions when assessing the viability and spatial requirements for a development.